Federal Register Vol. 80, No.154,

On June 16, 2015, Keeping Babies Safe (referred to as “KBS” or “petitioner”), submitted a petition to the Commission to initiate a rulemaking to ban supplemental mattresses for play yards with non-rigid sides, which are currently marketed to be used with non-full-size cribs, play yards, portable cribs, and play pens under the Commission's authority under section 8 of the Consumer Product Safety Act (“CPSA”), 15 U.S.C. 2057. KBS states that these supplemental mattresses should be deemed banned hazardous products because they present an unreasonable risk of injury and death to infants, and that no feasible consumer product safety standard would adequately protect infants from the unreasonable risk of injury and death associated with the product.1

In support, the petitioner asserts that KBS analyzed the death and injuries associated with supplemental mattresses, based on CPSC incident data. According to KBS, between 2000 and 2013, 15 incidents involving supplemental mattresses occurred in domestic settings and six incidents occurred in a child care setting. The petitioner states that all of the incidents involved a child being wedged between gaps created when a supplemental mattress was added to a play yard or portable crib. The petitioner additionally states that the data indicate that most of the supplemental mattresses involved in deaths exceeded 11/2 inches in thickness.

The petitioner also asserts that the current standard (ASTM F406-13, Standard Consumer Safety Specification for Non-Full-Size Baby Cribs/Play Yards) does not adequately address the risk of injury posed by supplemental mattresses. KBS states that although ASTM F406-13 requires each product to be sold with a mattress provided by the manufacturer with a total thickness not to exceed 11/2 inches, and contain warnings never to add a mattress, supplemental mattresses continue to be marketed to consumers for use in portable cribs and play yards. According to the petitioner, modifying the existing language in the current ASTM standard is not adequate to educate consumers about the unreasonable risk of injury that these mattresses pose to consumers. KBS states that, because supplemental mattresses continue to be sold to consumers, the most effective way to address the risk of injury caused by supplemental mattresses is to ban the product so that consumers do not have access to the product.

Interested parties may obtain a copy of the petition by writing or calling the Office of the Secretary, Consumer Product Safety Commission, 4330 East West Highway, Bethesda, MD 20814; email: [email protected]; telephone (301) 504-6833. The petition is also available at http://www.regulations.gov under Docket No. CPSC-2015-0020, Supporting and Related Materials.

Posting of Public Comments

Please note that all comments received in response to this docket are considered part of the public record. They will, unless reasonable cause is given, be made available by the Drug Enforcement Administration (DEA) for public inspection online at http://www.regulations.gov. Such information includes personal identifying information (such as your name, address, etc.) voluntarily submitted by the commenter. The Freedom of Information Act (FOIA) applies to all comments received. If you want to submit personal identifying information (such as your name, address, etc.) as part of your comment, but do not want it to be made publicly available, you must include the phrase “PERSONAL IDENTIFYING INFORMATION” in the first paragraph of your comment. You must also place the personal identifying information you do not want made publicly available in the first paragraph of your comment and identify what information you want redacted.

If you want to submit confidential business information as part of your comment, but do not want it to be made publicly available, you must include the phrase “CONFIDENTIAL BUSINESS INFORMATION” in the first paragraph of your comment. You must also prominently identify confidential business information to be redacted within the comment.

Comments containing personal identifying information and confidential business information identified as directed above will generally be made publicly available in redacted form. If a comment has so much confidential business information or personal identifying information that it cannot be effectively redacted, all or part of that comment may not be made publicly available. Comments posted to http://www.regulations.gov may include any personal identifying information (such as name, address, and phone number) included in the text of your electronic submission that is not identified as directed above as confidential.

An electronic copy of this document and supplemental information to this proposed rule are available at http://www.regulations.gov for easy reference.

Pursuant to 21 U.S.C. 811(a), this action is a formal rulemaking “on the record after opportunity for a hearing.” Such proceedings are conducted pursuant to the provisions of the Administrative Procedure Act (APA), 5 U.S.C. 551-559. 21 CFR 1308.41-1308.45; 21 CFR part 1316, subpart D. In accordance with 21 CFR 1308.44(a)-(c), requests for hearing, notices of appearance, and waivers of an opportunity for a hearing or to participate in a hearing may be submitted only by interested persons, defined as those “adversely affected or aggrieved by any rule or proposed rule issuable pursuant to section 201 of the Act (21 U.S.C. 811).” 21 CFR 1300.01. Such requests or notices must conform to the requirements of 21 CFR 1308.44(a) or (b), and 1316.47 or 1316.48, as applicable, and include a statement of interest of the person in the proceeding and the objections or issues, if any, concerning which the person desires to be heard. Any waiver must conform to the requirements of 21 CFR 1308.44(c) and 1316.49, including a written statement regarding the interested person's position on the matters of fact and law involved in any hearing.

Please note that pursuant to 21 U.S.C. 811(a), the purpose and subject matter of a hearing is restricted to: “find[ing] that such drug or other substance has a potential for abuse, and * * * mak[ing] with respect to such drug or other substance the findings prescribed by subsection (b) of section 812 of this title for the schedule in which such drug is to be placed * * *.” All requests for hearing and waivers of participation must be sent to the DEA using the address information provided above.

The DEA implements and enforces titles II and III of the Comprehensive Drug Abuse Prevention and Control Act of 1970, as amended. 21 U.S.C. 801-971. Titles II and III are referred to as the “Controlled Substances Act” and the “Controlled Substances Import and Export Act,” respectively, and are collectively referred to as the “Controlled Substances Act” or the “CSA” for the purpose of this action. The DEA publishes the implementing regulations for these statutes in title 21 of the Code of Federal Regulations (CFR), chapter II. The CSA and its implementing regulations are designed to prevent, detect, and eliminate the diversion of controlled substances and listed chemicals into the illicit market while ensuring an adequate supply is available for the legitimate medical, scientific, research, and industrial needs of the United States. Controlled substances have the potential for abuse and dependence and are controlled to protect the public health and safety.

Under the CSA, each controlled substance is classified into one of five schedules based upon its potential for abuse, its currently accepted medical use in treatment in the United States, and the degree of dependence the substance may cause. 21 U.S.C. 812. The initial schedules of controlled substances established by Congress are found at 21 U.S.C. 812(c), and the current list of all scheduled substances is published at 21 CFR part 1308.

Pursuant to 21 U.S.C. 811(a)(1), the Attorney General may, by rule, “add to such a schedule or transfer between such schedules any drug or other substance if he * * * finds that such drug or other substance has a potential for abuse, and * * * makes with respect to such drug or other substance the findings prescribed by subsection (b) of section 812 of this title for the schedule in which such drug is to be placed * * *.” The Attorney General has delegated scheduling authority under 21 U.S.C. 811 to the Administrator of the DEA. 28 CFR 0.100.

The CSA provides that scheduling of any drug or other substance may be initiated by the Attorney General (1) on her own motion; (2) at the request of the Secretary of Health and Human Services (HHS); or (3) on the petition of any interested party. 21 U.S.C. 811(a). If finalized, this action would impose the regulatory controls and administrative, civil, and criminal sanctions of schedule IV controlled substances for any person who handles eluxadoline.

Eluxadoline is a new molecular entity with central nervous system opioid properties. It has not been marketed in any country. Eluxadoline has mixed mu opioid receptor (MOR) and kappa opioid receptor (KOR) agonist and delta opioid receptor (DOR) antagonist properties. Recently, the Food and Drug Administration (FDA) approved eluxadoline as a prescription drug for the treatment of irritable bowel syndrome with diarrhea (IBS-d). Eluxadoline will be marketed as 75 and 100 milligrams (mg) oral tablets under the trade name of Viberzi.

Pursuant to 21 U.S.C. 811(a)(1), proceedings to add a drug or substance to those controlled under the CSA may be initiated by request of the Secretary of the HHS.1 The HHS provided the DEA with a scientific and medical evaluation document (dated May 5, 2015) prepared by the FDA entitled “Basis for the Recommendation to Place Eluxadoline and Its Salts into schedule IV of the Controlled Substances Act” and a scheduling recommendation. Pursuant to 21 U.S.C. 811(b), this document contained an eight-factor analysis of the abuse potential of eluxadoline as a new drug, along with the HHS' recommendation to control eluxadoline under schedule IV of the CSA.

In response, the DEA reviewed the scientific and medical evaluation and scheduling recommendation provided by the HHS, and all other relevant data, and completed its own eight-factor review document pursuant to 21 U.S.C. 811(c). Included below is a brief summary of each factor as analyzed by the HHS and the DEA, and as considered by the DEA in its proposed scheduling decision. Please note that both the DEA and the HHS analyses are available in their entirety under “Supporting and Related Material” in the public docket for this proposed rule at http://www.regulations.gov, under Docket Number “DEA-419N”. Full analysis of, and citations to, the information referenced in the summary may also be found in the supporting and related material.

1. The Drug's Actual or Relative Potential for Abuse: Eluxadoline is a new chemical entity that has not been marketed in the U.S. or in any other country. As such, there is no information available which details actual abuse of eluxadoline. However, the legislative history of the CSA suggests that the DEA consider the following criteria in determining whether a particular drug or substance has a potential for abuse: 2

Both the HHS and the DEA note that three of the above mentioned four criteria (1, 2, and 3) do not apply to eluxadoline for the following reasons. Eluxadoline is a new molecular entity and has not been marketed in any country. Accordingly, it has not been diverted from legitimate sources, and individuals have not taken this substance in amounts sufficient to create a hazard to public health or safety. Therefore, criterion 4 is the only one that applies to eluxadoline.

Eluxadoline acts as a high affinity agonist at MORs and KORs and as an antagonist at DORs. Eluxadoline produced opioid agonistic effects such as centrally mediated analgesia, sedation, motor impairment, respiratory depression, and death in some animals. Eluxadoline generalized to morphine in a drug discrimination study in monkeys suggesting its MOR agonist properties. Monkeys self-administered eluxadoline indicating its rewarding properties.

Receptor binding and functional profile studies demonstrate that eluxadoline has KOR agonistic activity. Pentazocine (schedule IV opioid analgesic) and butorphanol (schedule IV opioid analgesic) are the two currently marketed opioid drugs with KOR agonist activity. Pentazocine and butorphanol were initially approved for market as non-controlled drugs. However, subsequent reports of their actual abuse supported control as schedule IV drugs under the CSA. Clinical studies indicated that pentazocine and butorphanol have been shown to cause greater dysphoria and to be less abusable than the schedule II opioids.

In human abuse potential studies, eluxadoline produced both positive and negative responses. The maximal effects of eluxadoline on Drug Liking are greater than that of placebo, but less than that of oxycodone (schedule II). Eluxadoline produced small statistically significant increases in several positive subjective responses such as visual analog scale (VAS) scores for Take Drug Again, Subjective Drug Value, Good Drug Effects, High, and the Addiction Research Center Inventory-Morphine Benzedrine Group (ARCI-MBG, Euphoria). The positive subjective responses to eluxadoline were most often statistically significantly less than those produced by oxycodone. Eluxadoline produced a high rate of euphoria in human abuse potential studies. However, these euphoric effects of eluxadoline are less than that of oxycodone.

Eluxadoline at all doses elicited a small but significant increase in the VAS score for Drug Disliking. Eluxadoline also produced a statistically significant increase in VAS Bad Drug Effects, ARCI Lysergic Acid Diethylamide (ARCI-LSD, Dysphoria), but did not cause a significant increase in Drowsiness and Sedation. These results are also similar to those produced by pentazocine in a published study which reported a statistically significant increase in the VAS score for Bad Drug Effects and the score for ARCI-LSD (Dysphoria). Eluxadoline produced dysphoric effects consistent with kappa agonist activity related effects produced by pentazocine and butorphanol.

In summary, eluxadoline appears to be so related in its action to substances already listed as having potential for abuse, and which have been controlled in schedule IV of the CSA, to make it likely that eluxadoline will have the same potential for abuse as those substances.

2. Scientific Evidence of Its Pharmacological Effects, If Known: The HHS, in its scientific and medical evaluation document, reviewed data from pre-clinical and clinical studies on eluxadoline. The HHS' findings are summarized below.

Eluxadoline has high affinity at the MOR, KOR, and DOR. Eluxadoline lacked significant affinity for other binding sites including those associated with abuse potential. Similar to butorphanol (schedule IV), eluxadoline acted as an agonist at both MOR and KOR, but acted as an antagonist at DOR. Pentazocine (schedule IV) also has agonist activity at KOR.

In the Irwin test (a test of general behavioral responses), there were no noticeable behavioral changes produced by eluxadoline at three subcutaneous doses of 500, 1000, or 2000 mg/kg in mice. Similarly, there were no changes in motor activity, reflexes, excitation, body tone, righting reflex, and rotorod tests or in body temperature in rats following oral administration of eluxadoline (30 or 300 mg/kg). However, intravenous administration of eluxadoline HCl (5, 10 and 20 mg/kg/day) in rats for 14 days followed by a 14-day recovery period produced classic opioid-related behaviors including general arousal, handling reactivity, stereotypy, tail pinch response, touch response, changes in posture, gait, mobility, righting reflex, respiration, and hindlimb splay. In a toxicity study in Cynomolgus monkeys, animals treated with eluxadoline (50, 100, and 200 mg/kg/day) or vehicle via oral gavage for nine months, followed by a four-week recovery period (for the vehicle and 200 mg/kg groups), exhibited no changes in behavior during the 39-week treatment period. In a dose-finding study, daily intravenous administration of 20 mg/kg eluxadoline for seven days produced opioid-associated behaviors (decreased respiration and periods of unconsciousness). These effects were severely pronounced following 40 mg/kg dose. All animals in the highest dose group (40 mg/kg reduced to 30 mg/kg on the second day of the dosing after one animal died) exhibited opioid overdose symptoms such as decreased activity, unresponsiveness, decreased body temperature and respiration rates. Opioid antagonist naloxone (0.1 mg/kg) was administered either subcutaneously or intravenously to more or less severely affected animals, respectively. Upon reducing the eluxadoline dose from 40 mg/kg to 30 mg/kg, all animals continued to respond with opioid overdose symptoms.

In a hot-plate test for studying anti-nociceptive effects in mice, oral administration of eluxadoline up to doses of 1000 mg/kg showed no significant analgesic responses. However, subcutaneous administration of both 10 and 50 mg/kg eluxadoline caused significant increases in hot plate latencies and produced concurrent opioid-associated behaviors such as Straub tail and increased limb tone.

As mentioned in the HHS scientific and medical evaluation and scheduling recommendation, drug discrimination tests in animals serve as an important experimental method for predicting whether the effects of a given test drug will be similar to that of a standard training drug used in the study. In drug discrimination studies conducted in Rhesus monkeys trained to discriminate between subcutaneously administered morphine (1 mg/kg) and vehicle using shock stimulus termination procedure, intravenous administration of 17.8 mg/kg dose of eluxadoline HCl produced full generalization to morphine (1 mg/kg) in the only monkey tested. When this same monkey was tested at 10 mg/kg, there was no generalization. However, the 10 mg/kg dose of eluxadoline produced full generalization in a different monkey. The lowest doses of eluxadoline at 1.0 (n = 1) and 3.2 mg/kg (n = 2) produced no generalization (<20%) to morphine. Eluxadoline, as a mu and kappa opioid agonist, produces an interoceptive cue similar to that of mu opioid agonist, morphine (schedule II). These data are similar to those from several published human studies in which butorphanol (schedule IV, mu and kappa opioid agonist), pentazocine (schedule IV, kappa opioid agonist) and tramadol (schedule IV, mu opioid agonist prodrug) generalized to hydromorphone (schedule II, mu opioid agonist). Thus, these drug discrimination data demonstrate that mu opioid agonists will be recognized by animals and humans as having similar pharmacological properties to each other.

Drug self-administration tests in animals are used to evaluate the rewarding effects of drugs. There is a good correlation between those drugs that are self-administered by animals and those that are abused by humans. The data from self-administration studies provide a measure for abuse potential. In a self-administration study with monkeys (n = 5) trained to self-administer heroin (0.032 mg/kg/infusion in two monkeys or 0.01 mg/kg/infusion in three monkeys), the 0.32 and 1.0 mg/kg/infusion doses of eluxadoline HCl did not produce self-administration in one monkey trained to self-administer the higher 0.032 mg/kg/infusion dose of heroin, or in three other monkeys trained to self-administer the lower 0.001 mg/kg/infusion dose of heroin. When the highest dose of eluxadoline HCI (3.2 mg/kg/infusion) was tested first in the two monkeys trained at the 0.032 mg/kg/infusion dose of heroin, the self-administration rate of eluxadoline HCl (10-19 infusions/session) was less than that of heroin, but more than that of saline (2-4 infusions/session). The self-administration of eluxadoline in animals seems similar to that of the mu and kappa opioid agonist, butorphanol (schedule IV), a kappa opioid agonist, pentazocine (schedule IV) and another mu opioid agonist prodrug, tramadol (schedule IV).

In a clinical study, the abuse potential, safety, tolerability, and pharmacokinetics of orally administered eluxadoline (100, 300 and 1000 mg) were compared with positive control drug, oxycodone (30 and 60 mg) in healthy non-dependent recreational opioid users. Of the subjects who received any study treatment, a total of 33 subjects completed the study. On the primary subjective measure of VAS Drug Liking, eluxadoline at the two supratherapeutic doses (300 and 1000 mg) produced statistically significant higher maximum (Emax) scores on Drug Liking compared to placebo. When compared to that of either dose of oxycodone on Drug Liking, all three tested doses of eluxadoline (100, 300 and 1000 mg) showed statistically significant lower Emax scores. Eighteen of the 36 subjects who received eluxadoline showed a statistically significant positive response on Drug Liking with at least one of the eluxadoline doses tested. Data from the secondary subjective measures showed that oxycodone (30 and 60 mg) statistically significantly increased scores on other positive subjective responses such as the VAS for Overall Drug Liking, Take Drug Again, Subjective Drug Value, Good Drug Effects, High, and ARCI-MBG (Euphoria). At supratherapeutic oral doses (300 and/or 1000 mg), eluxadoline elicited statistically significant increases as compared to the placebo in positive subjective responses such as VAS for Take Drug Again, Subjective Drug Value, Good Drug Effects, High, and ARCI-MBG (Euphoria). The positive subjective responses to eluxadoline were most often statistically significantly less than those produced by either dose of oxycodone (30 and 60 mg). The HHS states that these results are similar to those produced by a kappa opioid agonist, pentazocine (schedule IV). Eluxadoline at all doses elicited a small but significant increase in the VAS score for Drug Disliking, but it happened one to two hours before the peak Drug Liking response. Furthermore, there were no statistically significant differences in Drug Disliking between eluxadoline and oxycodone (60 mg). Eluxadoline also produced a statistically significant increase in VAS Bad Drug Effects, and ARCI-LSD (Dysphoria), but did not cause a significant increase in Drowsiness and Sedation. These results are also similar to those produced by pentazocine in a published study which reported a statistically significant increase in the VAS score for Bad Drug Effects and the score for ARCI-LSD (Dysphoria).

Oral administration of eluxadoline produced an increase in several classical opioid-like adverse events (AEs) associated with mu opioid agonists. Eluxadoline (ranging from 14-28%) produced euphoria in a dose-dependent manner and it was greater than that after placebo (5%) but less than that of oxycodone (ranging from 73-76%). Eluxadoline induced centrally-mediated responses such as somnolence (ranging from 19-42%), and it overlaps with the rate reported for oxycodone (38-41%) and placebo (19%). Peripheral opioid-associated AEs such as dry mouth were also mentioned (11-19% for eluxadoline and 11-13% for oxycodone). Pruritus was also reported with a range of 8-11% for eluxadoline and 54-70% for oxycodone. The above AEs support that eluxadoline produced typical opioid-like effects, although these are less frequent than reported for oxycodone.

Another clinical study evaluated the abuse potential and safety of intranasal administration of crushed eluxadoline (100 and 200 mg) in comparison to crushed oxycodone HCl (crushed, 15 and 30 mg) in 31 healthy adult, non-dependent recreational opioid users. On the primary subjective measure of Drug Liking VAS, eluxadoline (100 and 200 mg) failed to produce Emax scores on Drug Liking that were statistically different from that of placebo while oxycodone at both tested doses (15 and 30 mg) produced statistically significant higher maximum (Emax) scores compared to placebo. Results for the secondary subjective measures show oxycodone (15 and 30 mg) significantly increased scores on positive subjective responses including the VAS for Overall Drug Liking, Take Drug Again, Subjective Drug Value, Good Drug Effects, High, and ARCI-MBG (Euphoria). Eluxadoline (100 and 200 mg) produced significant increases compared to placebo in these positive subjective responses. The positive subjective responses to eluxadoline were most often significantly less than those produced by either dose of oxycodone. Intranasal eluxadoline produced a small but statistically significant increase in the VAS for Drug Disliking while oxycodone did not. Eluxadoline also produced a significant increase in VAS Bad Drug Effects, ARCI-LSD (Dysphoria), Drowsiness, and Sedation. Oxycodone at both doses increased each of these negative subjective measurements, to a degree significantly greater than that of placebo but similar to the high dose of eluxadoline. Subjects identified eluxadoline as an opioid to a degree that was less than that of oxycodone. Intranasal administration of eluxadoline caused adverse events such as euphoria after the 100 mg (22%) and the 200 mg doses (19%). Rate of euphoria following eluxadoline was less than that of oxycodone at 15 mg (44%) and 30 mg (67%), and greater than placebo (0%). All incidences of euphoria produced by eluxadoline were mild in intensity.

The clinical efficacy studies conducted with oral eluxadoline (75 and 100 mg/BID) reported abuse-related AEs. The AE of euphoric mood was reported by only two IBS-d patients in the pooled Phase 2 and 3 safety trials (0.2% of population). The dose of eluxadoline for both these subjects was 100 mg BID. Similarly, the AE of “feeling drunk” was reported by only two subjects (0.1% of subjects in the 75 mg group and 0.1% of subjects in the 100 mg group). Other than euphoria, anxiety (1.7%) and somnolence (0.7%) were the most commonly reported abuse-related AEs. There were a few other central nervous system-associated AEs observed in clinical trials. These included headache (4.0-4.5%), dizziness (2.2-3.2%), and fatigue (1.9-2.6%). Thus there was a very low incidence of euphoria-related AEs in these clinical studies. It is not uncommon for patients participating in clinical studies to exhibit a low rate of euphoria-related AEs compared to participants in Phase I human abuse potential studies. This difference may be due to the underlying disease state of the patient population in clinical studies versus the healthy subject population in human abuse potential studies.

3. The State of Current Scientific Knowledge Regarding Eluxadoline: The chemical name of eluxadoline is 5-[[[(2S)-2-amino-3-[4-aminocarbonyl)-2,6-dimethylphenyl]-1-oxopropyl][(1S)-1-(4-phenyl-1H-imidazol-2-yl)ethyl]amino]methyl]-2-methoxybenzoic acid. The molecular formula of eluxadoline is C32H35N5O5 and its molecular weight is 569.65. Eluxadoline has two asymmetric carbons, and there are at least four different optical isomers. Because eluxadoline contains a primary amine and a carboxylic acid in its structure, the pH of the solution will determine whether the primary amine will be protonated (positively charged) and the carboxylic acid will be deprotonated (negatively charged). The synthesis of eluxadoline requires a high level of expertise and knowledge in organic chemistry. The tablets could be cracked and easily crushed by users with a tablet crusher or a mortar and pestle. However, the unique physicochemical properties of eluxadoline may present a challenge to isolate eluxadoline for purposes of abuse.

The half-life of eluxadoline is approximately five hours, with high inter-subject variability. Eluxadoline has a low oral bioavailability due to poor GI permeability and moderate hepatic first-pass extraction involving OATP1B1-mediated hepatic uptake of eluxadoline. Co-administration with food lowered systemic exposures. Biliary excretion accounted for over 80% of overall elimination, while there is a minimal elimination by renal excretion.

4. History and Current Pattern of Abuse: Because eluxadoline is a new molecular entity and has not been marketed in any country, information as to the history and current pattern of its abuse is not available. Data from pre-clinical and clinical studies indicated that eluxadoline shares pharmacological similarities with schedule IV drugs such as pentazocine and butorphanol and has similar abuse potential (see factors 1 and 2). Pentazocine and butorphanol were initially approved for market as non-controlled drugs. However, subsequent reports of actual abuse of pentazocine and butorphanol supported control as schedule IV drugs under the CSA. It is likely that eluxadoline, upon approval for marketing, will be abused for its rewarding effects.

Eluxadoline generalized to the stimulus effects of morphine (schedule II) in animal drug discrimination studies. These discriminative stimulus effects are similar to that for butorphanol, a schedule IV mu and kappa opioid receptor agonist and for pentazocine, a schedule IV kappa opioid receptor agonist. In two human abuse potential studies, eluxadoline produced both positive and negative subjective responses. The maximal effects of eluxadoline on Drug Liking are greater than that of placebo, but less than that of oxycodone (schedule II). Eluxadoline at all doses elicited a small but significant increase in the VAS score for Drug Disliking. The negative subjective responses of eluxadoline may be reflective of its kappa opioid receptor agonist properties and these are similar to those of schedule IV opioids, butorphanol and pentazocine. These dysphoric effects may indicate a lower abuse potential of a substance. In human abuse potential studies oral or intranasal administration of eluxadoline produced euphoria with a degree less than that of oxycodone.

As of May 20, 2015, no reports for eluxadoline were identified in either the National Forensic Laboratory Information System (NFLIS),3 or System to Retrieve Information on Drug Evidence (STRIDE).4

5. The Scope, Duration, and Significance of Abuse: Because eluxadoline is a new molecular entity and has not been marketed in any country, information as to the scope, duration and significance of its abuse is not available. Both pre-clinical and clinical studies indicate that eluxadoline shares pharmacological similarities with schedule IV drugs such as butorphanol and pentazocine and has similar abuse potential. Pentazocine and butorphanol were initially marketed as uncontrolled drugs. However subsequent reports of abuse of butorphanol and pentazocine led to their control as schedule IV drugs under the CSA. Thus, if eluxadoline were to be marketed as a non-controlled drug, it is likely to be abused for its rewarding properties. If uncontrolled, it is also likely that individuals seeking opioids will abuse eluxadoline as a substitute for other opioids that are controlled under the CSA.

In human abuse potential studies, eluxadoline produced both positive and negative subjective responses. The maximal effects of eluxadoline on Drug Liking are greater than that of placebo, but less than that of oxycodone (schedule II). Eluxadoline at all doses elicited a small but significant increase in the VAS score for Drug Disliking. The negative subjective responses of eluxadoline may be reflective of its kappa opioid receptor agonist properties and these are similar to those of schedule IV opioids, butorphanol and pentazocine. These dysphoric effects may indicate a lower abuse potential of eluxadoline.

6. What, If Any, Risk There Is To the Public Health: Data from pre-clinical and clinical studies indicate that eluxadoline has abuse potential similar to schedule IV opioids such as butorphanol and pentazocine. Abuse potential of a drug is considered a risk to the public health. Available information suggests that if eluxadoline were to be marketed as a non-controlled drug, it would be abused for its rewarding properties. The major concern regarding eluxadoline's risk to public health is based on animal studies in monkeys treated with eluxadoline, where the animals exhibited opioid overdose symptoms such as decreased activity, unresponsiveness, decreased body temperature, and decreased respiration rates. Severe sedation and slumping were also observed in monkeys following self-administration with eluxadoline. Furthermore, opioid-like effects of eluxadoline may not be reversible unless adequate or repeated administration of opioid antagonists such as naloxone or naltrexone is performed.

7. Its Psychic or Physiological Dependence Liability: Several pre-clinical studies both on Cynomolgus monkeys and rats treated with different doses of eluxadoline followed by various recovery or drug discontinuation periods showed no behavioral changes during the treatment period. There were also no behaviors suggestive of withdrawal during the observed recovery periods. Thus, chronic administration of eluxadoline did not result in withdrawal signs in laboratory monkeys and rats. However, monkeys self-administered eluxadoline. This suggests that eluxadoline has sufficient rewarding effects to induce reinforcement. In human subjects, the abuse-related AEs reported in clinical studies found that eluxadoline produced a low incidence of euphoria, “feeling drunk,” anxiety, somnolence, headache, abdominal pain, dizziness, and fatigue, which are suggestive of its ability to produce psychic dependence.

8. Whether the Substance is an Immediate Precursor of a Substance Already Controlled Under the CSA: Eluxadoline is not an immediate precursor of any substance controlled under the CSA.

Conclusion: Based on consideration of the scientific and medical evaluation conducted by the HHS and its recommendation, and after considering its own eight-factor analysis, the DEA has determined that these facts and all relevant data constitute substantial evidence of potential for abuse of eluxadoline. As such, the DEA hereby proposes to schedule eluxadoline as a controlled substance under the CSA.

The CSA establishes five schedules of controlled substances known as schedules I, II, III, IV, and V. The statute outlines the findings required in placing a drug or other substance in any schedule. 21 U.S.C. 812(b). After consideration of the analysis and recommendation of the Assistant Secretary for Health of the HHS and review of all available data, the Administrator of the DEA, pursuant to 21 U.S.C. 812(b), finds that:

Based on these findings, the Administrator of the DEA concludes that eluxadoline, including its salts, isomers and salts of isomers, whenever the existence of such salts, isomers, and salts of isomers is possible, warrants control in schedule IV of the CSA (21 U.S.C. 812(b)(4)).

If this rule is finalized as proposed, eluxadoline would be subject to the CSA's schedule IV regulatory controls and administrative, civil, and criminal sanctions applicable to the manufacture, distribution, dispensing, importing, exporting, research, and conduct of instructional activities involving schedule IV substances, including the following:

1. Registration. Any person who handles (manufactures, distributes, dispenses, imports, exports, engages in research, or conducts instructional activities with) eluxadoline, or who desires to handle eluxadoline, would be required to be registered with the DEA to conduct such activities pursuant to 21 U.S.C. 822, 823, 957, and 958 and in accordance with 21 CFR parts 1301 and 1312. Any person who currently handles eluxadoline, and is not registered with the DEA, would need to submit an application for registration and may not continue to handle eluxadoline as of the effective date of the final rule, unless the DEA has approved that application for registration, pursuant to 21 U.S.C. 822, 823, 957, 958, and in accordance with 21 CFR parts 1301 and 1312.

2. Security. Eluxadoline would be subject to schedule III-V security requirements and would need to be handled and stored pursuant to 21 U.S.C. 821, 823, 871(b) and in accordance with 21 CFR 1301.71-1301.93.

3. Labeling and Packaging. All labels and labeling for commercial containers of eluxadoline on or after finalization of this proposed rule would need to comply with 21 U.S.C. 825 and 958(e), and be in accordance with 21 CFR part 1302.

4. Inventory. Every DEA registrant who possesses any quantity of eluxadoline on the effective date of the final rule would be required to take an inventory of all stocks of eluxadoline on hand as of the effective date of the rule, pursuant to 21 U.S.C. 827 and 958, and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11(a) and (d).

Any person who becomes registered with the DEA after the effective date of the final rule must take an initial inventory of all stocks of controlled substances (including eluxadoline) on hand on the date the registrant first engages in the handling of controlled substances, pursuant to 21 U.S.C. 827 and 958 and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11(a) and (b).

After the initial inventory, every DEA registrant would be required to take an inventory of all controlled substances (including eluxadoline) on hand, on a biennial basis, pursuant to 21 U.S.C. 827 and 958, and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11.

5. Records. All DEA registrants would be required to maintain records with respect to eluxadoline pursuant to 21 U.S.C. 827 and 958, and in accordance with 21 CFR parts 1304, 1307, and 1312.

6. Prescriptions. All prescriptions for eluxadoline or products containing eluxadoline would need to comply with 21 U.S.C. 829, and be issued in accordance with 21 CFR parts 1306 and 1311, subpart C.

7. Importation and Exportation. All importation and exportation of eluxadoline would need to be in compliance with 21 U.S.C. 952, 953, 957, and 958, and in accordance with 21 CFR part 1312.

8. Criminal Liability. Any activity involving eluxadoline not authorized by, or in violation of, the CSA, occurring on or after finalization of this proposed rule, would be unlawful, and may subject the person to administrative, civil, and/or criminal sanctions.

In accordance with 21 U.S.C. 811(a), this proposed scheduling action is subject to formal rulemaking procedures performed “on the record after opportunity for a hearing,” which are conducted pursuant to the provisions of 5 U.S.C. 556 and 557. The CSA sets forth the procedures and criteria for scheduling a drug or other substance. Such actions are exempt from review by the Office of Management and Budget (OMB) pursuant to section 3(d)(1) of Executive Order 12866 and the principles reaffirmed in Executive Order 13563.

This proposed regulation meets the applicable standards set forth in Sections 3(a) and 3(b)(2) of Executive Order 12988 to eliminate drafting errors and ambiguity, minimize litigation, provide a clear legal standard for affected conduct, and promote simplification and burden reduction.

This proposed rulemaking does not have federalism implications warranting the application of Executive Order 13132. The proposed rule does not have substantial direct effects on the States, on the relationship between the national government and the States, or the distribution of power and responsibilities among the various levels of government.

This proposed rule will not have tribal implications warranting the application of Executive Order 13175. It does not have substantial direct effects on one or more Indian tribes, on the relationship between the Federal government and Indian tribes, or on the distribution of power and responsibilities between the Federal government and Indian tribes.

The Administrator, in accordance with the Regulatory Flexibility Act (RFA), 5 U.S.C. 601-612, has reviewed this proposed rule and by approving it certifies that it will not have a significant economic impact on a substantial number of small entities. The purpose of this proposed rule is to place eluxadoline, including its salts, isomers, and salts of isomers, into schedule IV of the CSA. No less restrictive measures (i.e., non-control, or control in schedule V) enable the DEA to meet its statutory obligations under the CSA. In preparing this certification, the DEA has assessed economic impact by size category and has considered costs with respect to the various DEA registrant business activity classes.

Eluxadoline is a new molecular entity which has not yet been marketed in the United States or any other country. Although the manufacturer is expected to enjoy market exclusivity for many years, the DEA has no basis to determine the level of contracted or outsourced manufacturing activities or the breadth of the distribution network. Furthermore, due to the wide variety of unidentifiable and unquantifiable variables that could potentially influence the dispensing and distribution rates of new pharmaceutical drugs, the DEA is unable to determine the number of potential small entities that might handle eluxadoline. However, the DEA estimates that all persons who would handle, or propose to handle, eluxadoline are currently registered with the DEA to handle schedule IV controlled substances, because it is a pharmaceutical controlled substance intended for medical treatment. Accordingly, the number of DEA registrations authorized to handle schedule IV controlled substances is a reasonable estimate for the maximum number of eluxadoline handlers. Therefore, the DEA estimates that 1.6 million (1,554,254 as of June 2015) controlled substance registrations, representing approximately 427,584 entities, would be the maximum number of entities affected by this rule. The DEA estimates that 418,141 (97.8%) of 427,584 affected entities are “small entities” in accordance with the RFA and SBA size standards.

The DEA anticipates that prospective eluxadoline handlers already handle other schedule IV controlled substances and that the cost impact as a result of placing eluxadoline in schedule IV would be nominal. As the anticipated eluxadoline handlers already handle other scheduled IV controlled substances, they already have DEA registrations and the required security and recordkeeping processes, equipment, and facilities in place, and would only require a nominal increase in security, inventory, recordkeeping and labeling costs.

As discussed above, while the DEA does not have a basis to estimate the number of affected entities, the DEA estimates that the maximum number of affected entities is 427,584 of which 418,141 are estimated to be small entities. Since the affected entities are expected to handle other schedule IV controlled substances and maintain security and recordkeeping facilities and processes consistent with schedule IV controlled substances, the DEA estimates any economic impact will be nominal. Because of these facts, this proposed rule will not result in a significant economic impact on a substantial number of small entities.

In accordance with the Unfunded Mandates Reform Act (UMRA) of 1995, 2 U.S.C. 1501 et seq., the DEA has determined and certifies that this action would not result in any Federal mandate that may result “in the expenditure by State, local, and tribal governments, in the aggregate, or by the private sector, of $100,000,000 or more (adjusted for inflation) in any one year.” Therefore, neither a Small Government Agency Plan nor any other action is required under UMRA of 1995.

This action does not impose a new collection of information requirement under the Paperwork Reduction Act of 1995, 44 U.S.C. 3501-3521. This action would not impose recordkeeping or reporting requirements on State or local governments, individuals, businesses, or organizations. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB control number.

For the reasons set out above, the DEA proposes to amend 21 CFR part 1308 as follows:

For additional information see the direct final rule which is published in the Rules Section of this Federal Register. A detailed rationale for the approval is set forth in the direct final rule and incorporated herein by reference. If no adverse comments are received in response to this rule, no further activity is contemplated. If EPA receives adverse comments, the direct final rule will be withdrawn and all public comments received will be addressed in a subsequent final rule based on this proposed rule. EPA will not institute a second comment period on this document. Any parties interested in commenting on this document should do so at this time.

On September 23, 2011, KY DAQ submitted a SIP revision to EPA for approval that makes several changes to Kentucky's regulations at 401 Kentucky Administrative Regulations (KAR) 51:052, Review of new sources in or impacting nonattainment areas. These regulations establish air quality permitting requirements for the construction or modification of major stationary sources located within, or impacting upon, areas designated nonattainment for any primary national ambient air quality standard. To ensure improvement of air quality in those areas, the emissions resulting from construction or modification of a major stationary source must be offset with compensating emission reductions.

Kentucky's requested SIP revision would revise 401 KAR 51:052 by: (1) Changing Section 5, paragraph (6)(b) to authorize new or modified sources to offset their emission increases with emission reductions achieved by shutting down an existing unit or curtailing production or operating hours prior to the new source application date (if specified conditions are met), (2) adding new and more comprehensive language to Section 5, paragraph (6)(b) describing how to calculate offsetting emission reductions obtained from a source shutdown or curtailment (3) amending Section 4, paragraph (3)(a) to establish an offset ratio of at least 1:1 for pollutants other than volatile organic compounds (VOCs) and nitrogen oxides (NOx), and (4) making changes to the introductory paragraph to 401 KAR 51:052 and Section 5, paragraph (3)(e) that update and clarify these provisions.

EPA has reviewed Kentucky's requested changes to 401 KAR 51:052, Review of new sources in or impacting nonattainment areas, and preliminarily concluded that these changes are consistent with the applicable CAA provisions and EPA's NNSR permitting regulations at 40 CFR 51.165. Specifically, the changes to Section 5, paragraph (6)(b) of 401 KAR 51:052 authorizing new or modified sources to offset emission increases with emission reductions generated by source shutdowns or curtailments occurring before the filing of a permit application for a new project are consistent with 40 CFR 51.165(a)(3)(ii)(C)(1). Likewise, the new regulatory language in Section 5, paragraph (6)(b) of 401 KAR 51:052 describing how to calculate emission offsets generated from source shutdowns or permanent curtailments also is consistent with 40 CFR 51.165(a)(3)(ii)(C)(1). The change to Section 4, paragraph (3)(a) of 401 KAR 51:052 specifying that increases in emissions shall be offset by reductions in emissions using a ratio of emission decreases to emission increases of at least 1:1 is required by 40 CFR 51.165(a)(9)(i). Finally, the changes to the introductory paragraph to 401 KAR 51:052 and Section 5 paragraph (3)(e) simply update and clarify these provisions and do not affect the consistency of these provisions with federal law. EPA has preliminarily determined that these changes are approvable pursuant to CAA section 110 and EPA's NNSR permitting regulations at 40 CFR 51.165.

In this rule, EPA is proposing to include in a final EPA rule regulatory text that includes incorporation by reference. In accordance with requirements of 1 CFR 51.5, EPA is proposing to incorporate by reference Kentucky Rule 401 KAR 51:052, Review of new sources in or impacting nonattainment areas. EPA has made, and will continue to make, these documents generally available electronically through www.regulations.gov and/or in hard copy at the appropriate EPA office (see the ADDRESSES section of this preamble for more information).

EPA is proposing to approve the Commonwealth of Kentucky's September 23, 2011, SIP revision. EPA has preliminarily determined that the changes to Kentucky's Rule 401 KAR 51:052, Review of new sources in or impacting nonattainment areas, are approvable because they are consistent with CAA section 110 and EPA's regulations regarding NNSR permitting at 40 CFR 51.165.

Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the Act and applicable Federal regulations. See 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the CAA. Accordingly, this proposed action merely approves state law as meeting Federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, this proposed action:

• Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011)

• does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);

• is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);

• does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);

• does not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);

• is not an economically significant regulatory action based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);

• is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);

• is not subject to requirements of Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA; and

• does not provide EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).

The SIP is not approved to apply on any Indian reservation land or in any other area where EPA or an Indian tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, the rule does not have tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), nor will it impose substantial direct costs on tribal governments or preempt tribal law.

Background

On April 27, 2015, we received a petition from Defenders of Wildlife to list the smooth hammerhead shark (Sphyrna zygaena) as threatened or endangered under the ESA throughout its entire range, or, as an alternative, to list any identified DPSs as threatened or endangered. To this end, the petitioners identified five populations that they indicate qualify for protection as DPSs: Northeast Atlantic and Mediterranean Sea, Northwest Atlantic, Southwest Atlantic, Eastern Pacific, and Indo-West Pacific. The petition also requests that critical habitat be designated for the smooth hammerhead shark under the ESA. In the case that the species does not warrant listing under the ESA, the petition requests that the species be listed based on its similarity of appearance to the listed DPSs of the scalloped hammerhead shark (Sphyrna lewini). Copies of the petition are available upon request (see ADDRESSES).

Section 4(b)(3)(A) of the ESA of 1973, as amended (16 U.S.C. 1531 et seq.), requires, to the maximum extent practicable, that within 90 days of receipt of a petition to list a species as threatened or endangered, the Secretary of Commerce make a finding on whether that petition presents substantial scientific or commercial information indicating that the petitioned action may be warranted, and to promptly publish such finding in the Federal Register (16 U.S.C. 1533(b)(3)(A)). When it is found that substantial scientific or commercial information in a petition indicates the petitioned action may be warranted (a “positive 90-day finding”), we are required to promptly commence a review of the status of the species concerned during which we will conduct a comprehensive review of the best available scientific and commercial information. In such cases, we conclude the review with a finding as to whether, in fact, the petitioned action is warranted within 12 months of receipt of the petition. Because the finding at the 12-month stage is based on a more thorough review of the available information, as compared to the narrow scope of review at the 90-day stage, a “may be warranted” finding does not prejudge the outcome of the status review.

Under the ESA, a listing determination may address a species, which is defined to also include subspecies and, for any vertebrate species, any DPS that interbreeds when mature (16 U.S.C. 1532(16)). A joint NMFS-U.S. Fish and Wildlife Service (USFWS) (jointly, “the Services”) policy clarifies the agencies' interpretation of the phrase “distinct population segment” for the purposes of listing, delisting, and reclassifying a species under the ESA (61 FR 4722; February 7, 1996). A species, subspecies, or DPS is “endangered” if it is in danger of extinction throughout all or a significant portion of its range, and “threatened” if it is likely to become endangered within the foreseeable future throughout all or a significant portion of its range (ESA sections 3(6) and 3(20), respectively, 16 U.S.C. 1532(6) and (20)). Pursuant to the ESA and our implementing regulations, we determine whether species are threatened or endangered based on any one or a combination of the following five section 4(a)(1) factors: The present or threatened destruction, modification, or curtailment of habitat or range; overutilization for commercial, recreational, scientific, or educational purposes; disease or predation; inadequacy of existing regulatory mechanisms; and any other natural or manmade factors affecting the species' existence (16 U.S.C. 1533(a)(1), 50 CFR 424.11(c)).

ESA-implementing regulations issued jointly by NMFS and USFWS (50 CFR 424.14(b)) define “substantial information” in the context of reviewing a petition to list, delist, or reclassify a species as the amount of information that would lead a reasonable person to believe that the measure proposed in the petition may be warranted. In evaluating whether substantial information is contained in a petition, the Secretary must consider whether the petition: (1) Clearly indicates the administrative measure recommended and gives the scientific and any common name of the species involved; (2) contains detailed narrative justification for the recommended measure, describing, based on available information, past and present numbers and distribution of the species involved and any threats faced by the species; (3) provides information regarding the status of the species over all or a significant portion of its range; and (4) is accompanied by the appropriate supporting documentation in the form of bibliographic references, reprints of pertinent publications, copies of reports or letters from authorities, and maps (50 CFR 424.14(b)(2)).

At the 90-day finding stage, we evaluate the petitioners' request based upon the information in the petition including its references and the information readily available in our files. We do not conduct additional research, and we do not solicit information from parties outside the agency to help us in evaluating the petition. We will accept the petitioners' sources and characterizations of the information presented if they appear to be based on accepted scientific principles, unless we have specific information in our files that indicates the petition's information is incorrect, unreliable, obsolete, or otherwise irrelevant to the requested action. Information that is susceptible to more than one interpretation or that is contradicted by other available information will not be dismissed at the 90-day finding stage, so long as it is reliable and a reasonable person would conclude it supports the petitioners' assertions. In other words, conclusive information indicating the species may meet the ESA's requirements for listing is not required to make a positive 90- day finding. We will not conclude that a lack of specific information alone negates a positive 90-day finding if a reasonable person would conclude that the unknown information itself suggests an extinction risk of concern for the species at issue.

To make a 90-day finding on a petition to list a species, we evaluate whether the petition presents substantial scientific or commercial information indicating the subject species may be either threatened or endangered, as defined by the ESA. First, we evaluate whether the information presented in the petition, along with the information readily available in our files, indicates that the petitioned entity constitutes a “species” eligible for listing under the ESA. Next, we evaluate whether the information indicates that the species faces an extinction risk that is cause for concern; this may be indicated in information expressly discussing the species' status and trends, or in information describing impacts and threats to the species. We evaluate any information on specific demographic factors pertinent to evaluating extinction risk for the species (e.g., population abundance and trends, productivity, spatial structure, age structure, sex ratio, diversity, current and historical range, habitat integrity or fragmentation), and the potential contribution of identified demographic risks to extinction risk for the species. We then evaluate the potential links between these demographic risks and the causative impacts and threats identified in section 4(a)(1).

Information presented on impacts or threats should be specific to the species and should reasonably suggest that one or more of these factors may be operative threats that act or have acted on the species to the point that it may warrant protection under the ESA. Broad statements about generalized threats to the species, or identification of factors that could negatively impact a species, do not constitute substantial information indicating that listing may be warranted. We look for information indicating that not only is the particular species exposed to a factor, but that the species may be responding in a negative fashion; then we assess the potential significance of that negative response.

Many petitions identify risk classifications made by nongovernmental organizations, such as the International Union on the Conservation of Nature (IUCN), the American Fisheries Society, or NatureServe, as evidence of extinction risk for a species. Risk classifications by other organizations or made under other Federal or state statutes may be informative, but such classification alone may not provide the rationale for a positive 90-day finding under the ESA. For example, as explained by NatureServe, their assessments of a species' conservation status do “not constitute a recommendation by NatureServe for listing under the U.S. Endangered Species Act” because NatureServe assessments “have different criteria, evidence requirements, purposes and taxonomic coverage than government lists of endangered and threatened species, and therefore these two types of lists should not be expected to coincide” http://www.natureserve.org/prodServices/pdf/NatureServeStatusAssessmentsListing-Dec%202008.pdf. Additionally, species classifications under IUCN and the ESA are not equivalent; data standards, criteria used to evaluate species, and treatment of uncertainty are also not necessarily the same. Thus, when a petition cites such classifications, we will evaluate the source of information that the classification is based upon in light of the standards on extinction risk and impacts or threats discussed above.

The smooth hammerhead shark is a circumglobal species found in temperate to warm waters (Compagno, 1984). It occurs close inshore and in shallow waters, over continental shelves, in estuaries and bays, and around coral reefs, but it has also been observed offshore at depths as great as 65-650 feet (20-200 meters (m)) deep (Compagno, 1984; Bester, n.d.). Smooth hammerheads are highly mobile and, within the Sphyrnidae family, are the most tolerant of temperate waters (Compagno, 1984). In the western Atlantic Ocean, the range of the smooth hammerhead shark extends from Nova Scotia to Florida and into the Caribbean Sea, and in the south from southern Brazil to southern Argentina (Compagno, 1984; Bester, n.d). In the eastern Atlantic Ocean, smooth hammerhead sharks can be found from the British Isles to Guinea and farther south through parts of equatorial West Africa. They are also found throughout the Mediterranean Sea (Compagno, 1984; Bester, n.d). In the Indian Ocean, the shark occurs from South Africa, along the southern coast of India and Sri Lanka, to the coasts of Australia. Distribution in the Pacific extends from Vietnam to Japan and includes Australia and New Zealand in the west, the Hawaiian Islands in the central Pacific, and extends from Northern California to the Nayarit state of Mexico, and from Panama to southern Chile in the eastern Pacific (Compagno, 1984; Bester, n.d).

The smooth hammerhead shark gets its common name from its large, laterally expanded head that resembles a hammer (Bester, n.d.). The unique head shape allows for easy distinction of hammerheads of the Sphyrnidae family from other types of sharks. The smooth hammerhead is characterized by a ventrally located and strongly arched mouth with smooth or slightly serrated teeth (Compagno, 1984). The body of the shark is fusiform with a moderately hooked first dorsal fin and a lower second dorsal fin, and its color ranges from a dark olive to greyish-brown that fades into a white underside (Bester, n.d.).

The general life history characteristics of the smooth hammerhead shark are that of a long-lived, slow-growing, and late maturing species (Compagno, 1984; Casper et al., 2005). The smooth hammerhead can reach a maximum length of 16 feet (5 m) and a maximum weight of 880 pounds (400 kilograms (kg)) (Bester, n.d.). Females are considered sexually mature at the age of 9, which correlates to size at sexual maturity of 8.7 feet (2.65 m) (Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), 2013). Males are considered sexually mature slightly earlier in life than females, and at sizes from 8.2-8.7 feet (2.10-2.65 m.) (CITES, 2013). The smooth hammerhead shark is viviparous (i.e., give birth to live young), with a gestation period of 10-11 months, and likely breeds every other year (ICCAT, 2012; Bester, n.d.). Litter sizes range from 20 to 40 live pups with a mean litter size of 33.5 pups. Average length at birth is estimated to be 50 cm (Bester, n.d.).

The smooth hammerhead shark is a high trophic level predator (Cortés, 1999) and opportunistic feeder that consumes a variety of teleosts, small sharks, skates and stingrays, crustaceans, and cephalopods (Compagno, 1984). The species has also been observed scavenging from nets and hooks.

The petition contains information on the species, including the taxonomy, species description, geographic distribution, habitat, population status and trends, and factors contributing to the species' decline. According to the petition, all five causal factors in section 4(a)(1) of the ESA are adversely affecting the continued existence of the smooth hammerhead shark: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) inadequacy of existing regulatory mechanisms; and (E) other natural or manmade factors affecting its continued existence.

In the following sections, we evaluate the information provided in the petition and readily available in our files to determine if the petition presents substantial scientific or commercial information indicating that an endangered or threatened listing may be warranted as a result of any of these ESA factors. Because we were requested to list a global population and, alternatively, DPSs, we will first determine if the petition presents substantial information that the petitioned action is warranted for the global population. If it does, then we will make a positive finding on the petition and conduct a review of the species range-wide. If after this review we find that the species does not warrant listing range-wide, then we will consider whether the populations requested by the petitioners qualify as DPSs and warrant listing. If the petition does not present substantial information that the global population may warrant listing, and it has requested that we list any populations of the species as threatened or endangered, then we will consider whether the petition provides substantial information that the requested population(s) may qualify as DPSs under the discreteness and significance criteria of our joint DPS Policy, and if listing any of those DPSs may be warranted. Below, we summarize the information presented in the petition and in our files on the status of the species and the ESA section 4(a)(1) factors that may be affecting the species' risk of global extinction and determine whether a reasonable person would conclude that an endangered or threatened listing may be warranted as a result of any of these factors.

The petition does not provide an estimate of global population abundance or trends for the smooth hammerhead shark. The petition refers to the IUCN Redlist status assessment (Casper et al., 2005) and its classification of the smooth hammerhead as globally “vulnerable.” The IUCN assessment cites overutilization by global fisheries as the main threat to the species, with smooth hammerheads both targeted and caught as bycatch and kept for their fins.

The petition provides evidence of population declines in a number of regions throughout the smooth hammerhead's range that would indicate that smooth hammerhead sharks may be experiencing declines on a global scale. For example, a stock assessment of smooth hammerhead sharks in the Northwest Atlantic region, conducted by Hayes (2007), estimated a 91 percent decline of the population between 1981 and 2005. Similarly, another study (Myers et al., 2007) used standardized catch per unit effort (CPUE) data from shark-targeted, fishery-independent surveys off the east coast of the United States and found a 99 percent decline of smooth hammerhead sharks from 1972-2003. Myers et al. (2007) remarks that the trends in abundance may be indicative of coast-wide population declines because the survey was situated “where it intercepts sharks on their seasonal migrations.” In the southwest Atlantic, Brazilian commercial fisheries report an 80 percent decline in CPUE of the hammerhead complex (including smooth hammerhead sharks) from 2000 to 2008, suggesting a significant decline in abundance of hammerhead sharks from this area (FAO, 2010). The State of Rio Grande do Sul, Brazil, experienced a 65 percent decrease in CPUE from 2000-2002, specifically of smooth hammerhead sharks (CITES, 2013). In the Mediterranean Sea, estimated declines of the Sphyrna complex (with S. zygaena comprising the main species) exceeded 99 percent over the last century, with hammerhead sharks considered to be functionally extinct in the region (Feretti et al., 2008). In the Indian Ocean, tagging surveys conducted off the eastern coast of South Africa over the course of 25 years suggest smooth hammerhead abundance has declined, after reaching a peak in 1987 (n = 468, 34.9 percent of the total smooth hammerheads tagged over the course of the study; Diemer et al., 2007). However, catches of smooth hammerhead sharks in beach protective nets set off the KwaZulu-Natal beaches in South Africa were highly variable from 1978-2003, with no clear trend that could indicate the status of the population (Dudley and Simpfendorfer, 2006). In the Eastern Pacific, incidental catches of smooth hammerhead sharks by tuna purse-seine vessels have exhibited a declining trend, from a peak of 1,205 sharks caught in 2004 to 436 individuals in 2011 (a decrease of around 64 percent) (CITES, 2013). Based on the available information from these regions, we find evidence suggesting that the population abundance of smooth hammerhead sharks has declined significantly and may still be in decline. While data are limited with respect to population size and trends, we find the information presented in the petition and readily available in our files to be substantial information on smooth hammerhead shark abundance, trends, and status.

The petition contends that smooth hammerhead sharks are at risk of extinction throughout their range due to pollutants, especially those that are able to bioaccumulate and biomagnify to high concentrations at high trophic levels. Of particular concern to the petitioners are high mercury and polychlorinated biphenyl (PCB) concentrations in smooth hammerhead shark tissues. International agencies, such as the Food and Drug Administration and the World Health Organization, have set a recommended maximum of 1 µg/g concentration of mercury in seafood tissues (García-Hernández et al., 2007) for human consumption. Storelli et al. (2003) tested tissue samples from four smooth hammerhead sharks from the Mediterranean Sea and found that, on average, tissue samples from the liver and muscle had concentrations of mercury that greatly exceeded recommended limits (mean mercury concentration in muscle samples: 12.15 ± 4.60 µg/g, mean mercury concentration in liver samples: 35.89 ± 3.58 µg/g). Additionally, these specimens showed high concentrations of more chlorinated (hexa- and hepta-chlorinated) PCBs. Similarly, García-Hernández et al. (2007) found high concentrations of mercury in tissues of four smooth hammerhead sharks from the Gulf of California, Mexico (mean mercury concentration in muscle tissue: 8.25 ± 9.05 µg/g). Escobar-Sánchez (2010) also studied mercury concentrations in the muscle tissues of smooth hammerhead sharks from the Mexican Pacific, but out of 37 studied sharks, only one shark had a mercury concentration that exceeded the recommended limits. As stated previously, we look for information in the petition and in our files to indicate that not only is the particular species exposed to a factor, but that the species may be responding in a negative fashion. Despite providing evidence that smooth hammerhead sharks accumulate pollutants in their tissues, the petitioners fail to provide evidence that these concentrations of mercury and PCBs are causing detrimental physiological effects to the species or may be contributing significantly to population declines in smooth hammerhead sharks to the point where the species may be at risk of extinction. As such, we conclude that the information presented in the petition on threats to the habitat of the smooth hammerhead shark does not provide substantial information indicating that listing may be warranted for the species.

Information from the petition and in our files suggests that the primary threat to the smooth hammerhead shark is from overutilization by fisheries. Smooth hammerhead sharks are both targeted and taken as bycatch in many global fisheries. Smooth hammerhead sharks face fishing pressure from commercial, artisanal, and recreational fisheries that use a variety of gear types to harvest these sharks: Pelagic and bottom longlines, handlines, gillnets, purse seines, and pelagic and bottom trawls (Camhi et al., 2007). Smooth hammerhead sharks are mostly targeted for their large, high-quality fins for use in shark fin soup, which are then transported to Asian markets where they fetch a high market price ($88/kg in 2003) (Abercrombie et al., 2005). In the Hong Kong fin market, which is the largest fin market in the world, S. zygaena and S. lewini are mainly traded under a combined market category called Chun chi (Abercrombie et al., 2005; NMFS, 2014a). Based on data from 2000-2002, Chun chi is the second most traded category, comprising around 4-5 percent of the total fins traded in the Hong Kong market annually (Clarke et al., 2006; Camhi et al., 2007). This percentage of fins correlates to an estimated 1.3-2.7 million individuals of scalloped and smooth hammerhead sharks (equivalent to a biomass of 49,000-90,000 tons) traded in the Hong Kong market annually. Given their relatively high price and popularity in the Hong Kong market, there is concern that many smooth hammerhead sharks caught as incidental catch may be kept for the fin trade as opposed to released alive; however, as noted in the Great Hammerhead 12-month finding (79 FR 33509; June 11, 2014), there has also been a recent global push to decrease the demand of shark fins, especially for shark fin soup.

In the northwestern Atlantic, smooth hammerhead sharks are mainly caught as bycatch in the U.S. commercial longline and net fisheries and by U.S. recreational fishermen using rod and reel, albeit rarely (NMFS, 2014b). This is likely a reflection of the low abundance of the species. Between 1981 and 2005, Hayes (2007) estimated that the Northwest Atlantic population of smooth hammerhead shark suffered a 91 percent decline in size. As of 2005, the population was estimated to be at 19-24 percent of the biomass that would produce maximum sustainable yield (MSY), as defined by the Magnuson-Stevens Fishery Conservation and Management Act, and that the population was being fished at 150 percent of fishing mortality associated with MSY. Under 2005 catch levels, Hayes (2007) estimated that there was a 64 percent likelihood of smooth hammerhead shark recovery within 30 years. It is important to note that the term “recovery” as used by Hayes (2007) is defined under the Magnuson-Stevens Fishery Conservation and Management Act and is based on different criteria than threatened or endangered statuses under the ESA. As such, it does not necessarily indicate that a species may warrant listing under the ESA because it does not necessarily have any relationship to a species' extinction risk. Overutilization under the ESA means that a species has been or is being harvested at levels that pose a risk of extinction, not just at levels over MSY. However, we agree that the significant decline estimated for the population combined with the species' biological susceptibility to current fisheries and high at-vessel mortality rates (see Other natural or manmade factors affecting its continued existence section) may be of concern as it relates to the extinction risk of the species. In addition, we note that, as pointed out in the NMFS Great Hammerhead Shark Status Review (Miller et al., 2014), Hayes (2007) (cited as Hayes 2008 in the status review) identified many uncertainties in the data and catch estimates from his stock assessment model that may have affected population decline estimates and should be taken into consideration. We will evaluate these uncertainties and the adequacy of existing regulatory measures in preventing further declines in the species during the status review phase.

In the southwestern Atlantic, industrial landings of the hammerhead complex (mainly S. lewini and S. zygaena) off the coast of Santa Catarina, Brazil increased from 6.7 tons in 1989 to a peak of 570 tons in 1994, due to fast development of industrial net fishing during this time (CITES, 2013). However, catches of hammerheads from the industrial net fishery fell to 44 tons in 2008, despite continued fishing effort. Industrial deep fishing with bottom gillnets off the coast of Brazil is a threat to recruiting coastal hammerheads, especially during their mating and birthing seasons (CITES, 2013). Data from a bottom gillnet fishery targeting hammerheads off the coast of Brazil noted an 80 percent decline in CPUE of the hammerhead complex from 2000-2008 (FAO, 2010). The targeted hammerhead fishery was abandoned after 2008 when the species became too rare to make the fishery economically viable. In the Rio Grande do Sul State of Brazil, a 65 percent decrease in CPUE of smooth hammerhead sharks from the industrial fisheries was noted from 2000-2002, decreasing from 0.37 tons per trip to 0.13 tons per trip (CITES, 2013). The various fishing operations in this region concentrate effort in areas where all life stages of hammerhead sharks occur. For example, the artisanal net and industrial trawl fishing within inshore areas and on the continental shelf place neonates and juveniles at risk of fishery-related mortality, and the industrial gillnet and longline fisheries operating on the outer continental shelf and adjacent ocean waters place adults at risk (CITES, 2013). With this heavy fishing effort affecting all life stages, there may be observed declines in the population.

In the Mediterranean Sea, it is thought that smooth hammerheads may have been fished to functional extinction (Feretti et al., 2008). In the early 20th century, coastal fisheries would target large sharks and also land them as incidental bycatch in gill nets, fish traps, and tuna traps (Feretti et al., 2008). Feretti et al. (2008) hypothesized that certain species, including S. zygaena, found refuge in offshore pelagic waters from this intense coastal fishing. However, with the expansion of the tuna and swordfish longline and drift net fisheries into pelagic waters in the 1970s, these offshore areas no longer served as protection from fisheries, and sharks again became regular bycatch. Consequently, the hammerhead shark abundance in the Mediterranean Sea (primarily S. zygaena) is estimated to have declined by more than 99 percent over the past 107 years, with hammerheads considered to be functionally extinct in the region. Recently, Sperone et al. (2012) provided evidence of the contemporary occurrence of the smooth hammerhead shark in Mediterranean waters, recording seven individuals from 2000-2009 near the Calabria region of Italy. Additionally, the aforementioned toxicology study, Storelli et al. (2003), used four smooth hammerhead sharks that were caught as bycatch from the swordfish fishery in the Mediterranean in July of 2001. These two studies suggest that numbers of smooth hammerhead shark in the Mediterranean region may be slowly recovering (Sperone et al., 2012), although further study is needed.

In the waters off of northwestern Africa, hammerhead sharks are retained primarily as bycatch from the industrial fisheries and catch from the artisanal fisheries operating within this region. Historically, Spanish swordfish gillnet and longline fisheries and European industrial trawl fisheries caught significant amounts of hammerheads (Buencuerpo et al., 1998; Zeeberg et al., 2006). For example, from 1991-1992 a total of 675 hammerheads (the authors refer to them as scalloped hammerheads but give the scientific name of S. zygaena) were landed as incidental catch in the Spanish swordfish fishery, with juveniles comprising the majority of the catch (94 percent of males and 96 percent of females) (Buencuerpo et al., 1998). In a study of European trawl fisheries off the coast of Mauritania, 42 percent of the megafauna bycatch (the largest category) were hammerhead sharks and 75 percent of the hammerhead sharks were juveniles (Zeeberg et al., 2006). The study estimated that over 1,000 hammerheads are removed annually, a number considered to be unsustainable for the region. Additionally, according to a review of shark fishing in the Sub Regional Fisheries Commission member countries (Cape-Verde, Gambia, Guinea, Guinea-Bissau, Mauritania, Senegal, and Sierra Leone), Diop and Dossa (2011) state that shark fishing is an important component of the artisanal fishery. Before 1989, artisanal catch of sharks was less than 4,000 mt. However, from 1990 to 2005, shark catch increased dramatically from 5,000 mt to over 26,000 mt, as did the level of fishing effort (Diop and Dossa, 2011). However, from 2005 to 2008, shark landings dropped by more than 50 percent, to 12,000 mt (Diop and Dossa, 2011). As noted in the Scalloped Hammerhead Final Listing Rule (79 FR 38213; July 3, 2014), regulations in Europe appear to be moving towards the sustainable use and conservation of shark species; however, there is still concern regarding the level of exploitation of hammerhead sharks off the west coast of Africa, and the threat warrants further exploration.

In the eastern Pacific Ocean, smooth hammerhead sharks are both targeted and taken as bycatch in industrial and artisanal fisheries (Casper et al., 2005). In Mexico, sharks, in general, are an important component of the artisanal fishery (INP, 2006). They are targeted for both their fins, which are harvested by fishermen for export, and for their shark meat, which is becoming increasingly important for domestic consumption. In the Gulf of Tehuantepec, smooth hammerhead sharks are the seventh most important shark species (out of 21 identified species) caught in the artisanal fishery (INP, 2006). In a survey of the targeted artisanal elasmobranch fishery off the coast of Sinaloa, Mexico, smooth hammerhead sharks accounted for 6.4 percent (n = 70) of total landings in the more active winter season and 3 percent (n = 120) of the total surveyed catch from 1998-1999 (Bizzarro et al., 2009). Of concern is the fact that all individuals landed during this survey were juveniles. Similarly, a 1995-1996 survey of the artisanal fishery off the Tres Marinas Islands of Mexico demonstrated that smooth hammerhead sharks constituted 35 percent (n = 700) of the total catch, and only 20 percent of the females and 1 percent of the males were considered mature (Pérez-Jiménez et al., 2005). Given the species' low productivity, slow growth rate, and late maturity, this targeted removal of recruits from the population may cause or continue to cause declines in the abundance of the species to the point where it may be contributing to the species' risk of extinction and is cause for concern that warrants further review.

Smooth hammerhead sharks are also taken as bycatch by the tuna purse-seine fisheries operating in the Inter-American Tropical Tuna Commission convention area of the Eastern Pacific region. Based on data from observers, smooth hammerhead sharks constituted around 1.7 percent of the total bycatch from the tuna purse-seine fleet from 2000-2001. Since the mid-1980s, the tuna purse-seine fishery in the Pacific has been rapidly expanding (Williams and Terawasi, 2011), and despite the increase in fishery effort (or perhaps a consequence of this increased fishing pressure), incidental catch of smooth hammerhead sharks has seen a decline, from a peak of 1,205 individuals in 2004 to 436 individuals in 2011 (CITES, 2013).

In the west-coast based U.S. fisheries, hammerheads are primarily caught as bycatch, and, based on observer data, appear to be relatively rare in the fisheries catch. For example, in the California/Oregon drift gillnet fishery, which targets swordfish and common thresher shark and operates off the U.S. Pacific coast, observers recorded only 70 bycaught smooth hammerheads and 2 unidentified hammerheads in 8,698 sets conducted over the past 25 years (from 1990-2015; WCR, 2015).

Throughout the majority of the Indian Ocean and western Pacific, fisheries data in the petition and available in our files are lacking, but shark finning and illegal, unregulated and unreported (IUU) fishing were identified by the petitioners as threats contributing to the overutilization of the species in these areas. The smooth hammerhead shark is caught in both artisanal and commercial fisheries as directed catch and retained incidental bycatch (Casper et al., 2005). Pelagic fisheries from industrialized countries have been active in the region for over 50 years (Casper et al., 2005). A recent review of fisheries in the Indian Ocean reports that sharks in the area are fully or over-exploited (de Young, 2006), but due to the high levels of IUU fishing and lack of species-specific catch reporting, it is difficult to determine the rate of exploitation of smooth hammerhead sharks. In Western Australia, smooth hammerhead sharks are retained as bycatch in the demersal gillnet fishery, but it appears that the fishing pressure is too low to have impacted populations in this region (Casper et al., 2005). Smooth hammerheads are relatively common around New Zealand's North Island, where they are frequently caught as bycatch in commercial gillnets and trawls; however, these individuals are often discarded dead (Casper et al., 2005).

In the central Pacific, smooth hammerhead sharks are bycaught in the Hawaii-based fisheries, but comprise a very small proportion of the bycatch. In fact, from 1995-2006, only 49 smooth hammerhead sharks and 38 unidentified hammerhead sharks were bycaught in the Hawaiian longline fishery, amounting to less than 0.1 percent of all bycaught shark species in the fishery for that time period (Walsh et al., 2009). According to the U.S. National Bycatch Report (NMFS, 2011; NMFS, 2013), the Hawaii-based deep-set pelagic longline fishery (which targets swordfish) bycaught 3,173.91 pounds (1440 kg) of smooth hammerhead in 2010, an increase of around 29 percent from the amount reported in 2005 (2,453.74 pounds (1,113 kg)). However, for the Hawaii based shallow-set pelagic longline fishery (which also targets swordfish), there were no reports of bycaught smooth hammerhead sharks in 2010, whereas in 2005, 930.35 pounds (422 kg) of smooth hammerheads were recorded as bycatch. Additionally, in 2011, an estimated 12 smooth hammerhead sharks (based on extrapolated observer data) were taken in the American Samoa longline fishery (PIFSC, unpublished data). Further review is necessary to determine if this level of fishery-related mortality is a threat to the smooth hammerhead shark.

Given the evidence of historical exploitation of the species and subsequent population declines, and the fact that fishing pressure from industrial and artisanal fisheries may still be high based on available fisheries data and the high value and contribution of smooth hammerhead fins to the international fin trade, we conclude that the information in the petition and in our files suggest that global fisheries are impacting smooth hammerhead shark populations to a degree that raises concern that the species may be at risk of extinction.

The petition asserts that high concentrations of arsenic in smooth hammerhead shark tissues should be considered a significant threat to smooth hammerhead shark populations as it is a possible carcinogenic. The petition refers to Storelli et al. (2003), which found that smooth hammerhead sharks (n = 4) had a mean arsenic concentration in muscle samples of 18.00 ± 8.57 µg/g and a mean arsenic concentration in liver samples of 44.22 ± 2.22 µg/g. The study cites that sharks rarely have arsenic concentrations that exceed 10 µg/g, and so the arsenic levels in the sharks tissues should be considered “notably elevated” (Storelli et al., 2003). The petitioners contend that the smooth hammerhead sharks are at a higher risk for developing cancer due to these high levels of arsenic. However, as already stated, we look for information in the petition and in our files to indicate that not only is the particular species exposed to a factor, but that the species may be responding in a negative fashion. Despite providing evidence that some smooth hammerhead sharks have elevated levels of arsenic in their tissues, the petitioners fail to show that those specific levels are causing detrimental physiological effects or may be contributing significantly to population declines in smooth hammerhead sharks to the point where the species may be at risk of extinction. Additionally, neither the petitioners nor the information in our files indicate that predation is a significant threat to this apex species. As such, we conclude that the information presented in the petition on the threats of disease or predation to the smooth hammerhead shark does not provide substantial information indicating that listing may be warranted for the species.

The petition asserts that the existing international, regional, and national regulations do not adequately protect the smooth hammerhead shark and have been insufficient in preventing population declines. Additionally, the petition asserts that most existing regulations are inadequate because they limit retention of the smooth hammerhead shark and argues that the focus should be on limiting the catch of smooth hammerhead sharks in order to decrease fishery-related mortality, particularly given the species' high post-catch mortality rates. Among the regulations that the petition cites as inadequate are shark finning bans and shark finning regulations. Shark finning bans are currently one of the most widely used forms of shark utilization regulations, and the petition notes that 21 countries, the European Union, and 9 Regional Fisheries Management Organizations (RFMOs) have implemented shark finning bans (CITES, 2013). However, the petition contends that these shark finning bans are often ineffective as enforcement is difficult or lacking, implementation in RFMOs and international agreements is not always binding, and catches often go unreported (CITES, 2013). The petition also states that shark finning regulations tend to have loopholes that can be exploited to allow continued finning. Many shark finning regulations require that both the carcass and the fins be landed, but not necessarily naturally attached. Instead, the regulations impose a fin to carcass ratio weight, which is usually 5 percent (Dulvy et al., 2008). This allows fishermen to preferentially retain the carcasses of valuable species and valuable fins from other species in order to maximize profits (Abercrombie et al., 2005). In 2010, the United States passed the Shark Conservation Act, which except for a limited exception regarding smooth dogfish, requires all sharks to be landed with their fins attached, abolishing the fin to carcass ratio. However, in other parts of the species' range, the inadequacy of existing finning bans may be contributing to further declines in the species by allowing the wasteful practice of shark finning at sea to continue.

In the Atlantic United States, smooth hammerhead sharks are managed as part of the Large Coastal Shark (LCS) complex group under the U.S. Highly Migratory Species Fishery Management Plan (HMS FMP). The petition asserts that the inclusion of smooth hammerheads in the LCS complex offers minimal to no protection to the smooth hammerhead shark, and that implementation of Amendment 5 to the HMS FMP does not cover smooth hammerhead sharks. We find that the petitioners are incorrect in their assertion.

Amendments, in general, are rulemakings that amend FMPs, and in 2012, NMFS published a draft of Amendment 5 to the 2006 HMS FMP (77 FR 73029) that proposed measures designed to reduce fishing mortality and effort in order to rebuild various overfished Atlantic shark species while ensuring that a limited sustainable shark fishery for certain species could be maintained. After considering all of the public comments on Draft Amendment 5, NMFS split Amendment 5 into two rulemakings: Amendment 5a (which addressed scalloped hammerhead, sandbar, blacknose, and Gulf of Mexico blacktip sharks) and Amendment 5b (which addressed dusky sharks).

Amendment 5a was implemented in 2013 (78 FR 40318) and was a rulemaking designed to maintain the rebuilding of sandbar sharks, end overfishing and rebuild scalloped hammerhead and Atlantic blacknose sharks, establish total allowable catches (TAC) and commercial quotas for Gulf of Mexico blacknose and blacktip sharks, and establish new recreational shark fishing management measures. Although Amendment 5a focuses specifically on the rebuilding of scalloped hammerhead sharks, the regulatory measures affect and likely benefit the entire hammerhead complex. For example, with the implementation of Amendment 5a, commercial hammerhead shark quotas (which include smooth, scalloped and great hammerheads) have been separated from the aggregated LCS management group quotas, with links between the Atlantic hammerhead shark quota and the Atlantic aggregated LCS quotas, and links between the Gulf of Mexico hammerhead shark quota and Gulf of Mexico aggregated LCS quotas. In other words, if either the aggregated LCS or hammerhead shark quota is reached, then both the aggregated LCS and hammerhead shark management groups will close. These quota linkages were implemented as an additional conservation benefit for the hammerhead shark complex due to the concern of hammerhead shark bycatch and additional mortality from fishermen targeting other sharks within the LCS complex. The separation of the hammerhead species for quota monitoring purposes from other sharks within the LCS management unit allows for better management of the specific utilization of the hammerhead shark complex, which includes smooth hammerhead sharks.

Additionally, although the petition asserts that Amendment 5 did not cover the smooth hammerhead shark, it acknowledges that an applicable protection for smooth hammerhead sharks from Amendment 5a is the minimum size catch requirement for recreational fishermen, which has been set at 6.5 feet (198 cm). However, the petition notes that this minimum size is below the size at maturity for smooth hammerhead sharks (estimated at 210-250 cm for males and 270 cm for females), and, as such, allows for the continued catch of immature smooth hammerhead sharks.

Finally, although not part of Amendment 5a but still applicable to the smooth hammerhead shark, we note that starting in 2011, U.S. fishermen using pelagic longline (PLL) gear and operating in the Atlantic Ocean, including the Caribbean Sea, and dealers buying from vessels that have PLL gear onboard, have been prohibited from retaining onboard, transshipping, landing, storing, selling, or offering for sale any part or whole carcass of hammerhead sharks of the family Sphyrnidae (except for S. tiburo) (76 FR 53652; August 29, 2011). This prohibition provides an additional benefit to the species by reducing the fishery-related mortality of this species within the Atlantic.

While we find that the petitioners are incorrect in their assertion that the inclusion of smooth hammerheads in the LCS complex offers minimal to no protection to the smooth hammerhead shark and the implementation of Amendment 5 (presumably Amendment 5a) does not cover smooth hammerhead sharks, we will evaluate the adequacy of these and the other existing regulations in relation to the threat of overutilization of the species during the status review.

In terms of other national measures, the petition provides a list of countries that have prohibited shark fishing in their respective waters, but notes that many suffer from enforcement related issues, citing cases of illegal fishing and shark finning. The petition also highlights enforceability issues associated with international agreements regarding smooth hammerhead shark utilization and trade. Based on the information presented in the petition as well as information in our files, we find that further evaluation of the adequacy of existing regulatory measures is needed to determine whether this may be a threat contributing to the extinction risk of the species.

The petition contends that “biological vulnerability” in the form of long gestation periods, late maturity, large size, relatively infrequent reproduction, and high post-catch mortality rates exacerbate the threat of overutilization and increase the species' susceptibility to extinction. The petition cites Cortés et al. (2010), which estimated a post-release mortality of 85 percent for smooth hammerheads caught on pelagic longline. In New South Wales, Australia, Reid and Krogh (1992) examined shark mortality rates in protective beach nets set off the coast between 1950 and 1990, and found that only 1.7 percent of the total number of hammerheads caught in the net (total =2,031 sharks) were still alive when the nets were cleared. These high post-release mortality rates increases the sharks' vulnerability to fishing pressure, with any capture of this species, regardless of whether the fishing is targeted or incidental, contributing to its fishing mortality. However, in an ecological risk assessment of 20 shark stocks, Cortés et al. (2010) found that the smooth hammerhead ranked among the least vulnerable sharks to pelagic longline fisheries in the Atlantic Ocean, although the authors note that the amount and quality of data regarding the species was considerably lower than for the other species. Overall, this information suggests that the species' biological vulnerability (low productivity and high post-release mortality) may be a threat in certain fisheries, possibly contributing to an increased risk of extinction, but may not be a cause for concern in other fisheries.

The petition also contends that the species' tendency to form juvenile aggregations increases the species' susceptibility to extinction. Juveniles of the species have been known to aggregate in shallow, coastal waters (Zeeberg et al., 2006; Diemer et al., 2011; CITES, 2013), which increases the species' susceptibility to being caught in large numbers. These shallow areas are close to coastlines and, as such, generally face heavier fishing pressure from commercial, artisanal, and recreational fisheries. Many studies of targeted and retained bycatch shark fisheries have demonstrated that a large amount of the catch of smooth hammerhead sharks are juveniles (Bizzarro et al., 1998; Buencuerpo et al., 1998; Zeeberg et al., 2006; Diemer et al., 2007). The removal of substantial numbers of juveniles from a population can have significant effects on recruitment to the population and could lead to population declines and potentially extinction of a species. Given the observed declines in the species, this juvenile aggregating behavior and, consequently, increased susceptibility to being caught in large numbers, may be a threat that is contributing to the extinction risk of the species.

Thus, the available information in the petition and in our files suggests that the species' natural biological vulnerability (including high post-catch mortality rates and aggregating behavior) may present a threat that warrants further exploration to see if it is exacerbating the threat of overutilization and contributing to the species' risk of extinction that is cause for concern.

We conclude that the petition presents substantial scientific or commercial information indicating that a combination of three of the section 4(a)(1) factors (overutilization for commercial, recreational, scientific, or educational purposes; inadequate existing regulatory mechanisms; and other natural factors) may be causing or contributing to an increased risk of extinction for the smooth hammerhead shark.

After reviewing the information contained in the petition, as well as information readily available in our files, and based on the above analysis, we conclude the petition presents substantial scientific information indicating the petitioned action of listing the smooth hammerhead shark as threatened or endangered may be warranted. Therefore, in accordance with section 4(b)(3)(B) of the ESA and NMFS' implementing regulations (50 CFR 424.14(b)(2)), we will commence a status review of the species. During our status review, we will first determine whether the species is in danger of extinction (endangered) or likely to become so (threatened) throughout all or a significant portion of its range. If it is not, then we will consider whether the populations identified by the petitioners meet the DPS policy criteria, and if so, whether any of these are threatened or endangered. If no populations meet the DPS policy criteria, then we will consider whether a similarity of appearance listing is warranted. We now initiate this review, and thus, the smooth hammerhead shark is considered to be a candidate species (69 FR 19975; April 15, 2004). Within 12 months of the receipt of the petition (April 27, 2016), we will make a finding as to whether listing the species (or any petitioned DPSs) as endangered or threatened is warranted as required by section 4(b)(3)(B) of the ESA. If listing the species (or any petitioned DPSs) or a similarity of appearance listing is found to be warranted, we will publish a proposed rule and solicit public comments before developing and publishing a final rule.

To ensure that the status review is based on the best available scientific and commercial data, we are soliciting information on whether the smooth hammerhead shark is endangered or threatened. Specifically, we are soliciting information in the following areas: (1) Historical and current distribution and abundance of this species throughout its range; (2) historical and current population trends; (3) life history in marine environments, including identified nursery grounds; (4) historical and current data on smooth hammerhead shark bycatch and retention in industrial, commercial, artisanal, and recreational fisheries worldwide; (5) historical and current data on smooth hammerhead shark discards in global fisheries; (6) data on the trade of smooth hammerhead shark products, including fins, jaws, meat, and teeth; (7) any current or planned activities that may adversely impact the species; (8) ongoing or planned efforts to protect and restore the species and its habitats; (9) population structure information, such as genetics data; and (10) management, regulatory, and enforcement information. We request that all information be accompanied by: (1) Supporting documentation such as maps, bibliographic references, or reprints of pertinent publications; and (2) the submitter's name, address, and any association, institution, or business that the person represents.

A complete list of references is available upon request to the Office of Protected Resources (see ADDRESSES).

The authority for this action is the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

On April 27, 2015, we received a petition from Defenders of Wildlife requesting that we list the bigeye thresher shark (Alopias superciliosus) as endangered or threatened under the ESA, or, in the alternative, to list one or more distinct population segments (DPSs), should we find they exist, as threatened or endangered under the ESA. Defenders of Wildlife also requested that critical habitat be designated for this species in U.S. waters concurrent with final ESA listing. The petition states that the bigeye thresher shark merits listing as an endangered or threatened species under the ESA because of the following: (1) The species faces threats from historical and continued fishing for both commercial and recreational purposes; (2) life history characteristics and limited ability to recover from fishing pressure make the species particularly vulnerable to overexploitation; and (3) regulations are inadequate to protect the bigeye thresher shark.

Section 4(b)(3)(A) of the ESA of 1973, as amended (U.S.C. 1531 et seq.), requires, to the maximum extent practicable, that within 90 days of receipt of a petition to list a species as threatened or endangered, the Secretary of Commerce make a finding on whether that petition presents substantial scientific or commercial information indicating that the petitioned action may be warranted, and promptly publish the finding in the Federal Register (16 U.S.C. 1533(b)(3)(A)). When we find that substantial scientific or commercial information in a petition and in our files indicates the petitioned action may be warranted (a “positive 90-day finding”), we are required to promptly commence a review of the status of the species concerned, which includes conducting a comprehensive review of the best available scientific and commercial information. Within 12 months of receiving the petition, we must conclude the review with a finding as to whether, in fact, the petitioned action is warranted. Because the finding at the 12-month stage is based on a significantly more thorough review of the available information, a “may be warranted” finding at the 90-day stage does not prejudge the outcome of the status review.

Under the ESA, a listing determination may address a “species,” which is defined to also include subspecies and, for any vertebrate species, any DPS that interbreeds when mature (16 U.S.C. 1532(16)). A joint NMFS-U.S. Fish and Wildlife Service (USFWS) policy clarifies the agencies' interpretation of the phrase “distinct population segment” for the purposes of listing, delisting, and reclassifying a species under the ESA (“DPS Policy”; 61 FR 4722; February 7, 1996). A species, subspecies, or DPS is “endangered” if it is in danger of extinction throughout all or a significant portion of its range, and “threatened” if it is likely to become endangered within the foreseeable future throughout all or a significant portion of its range (ESA sections 3(6) and 3(20), respectively; 16 U.S.C. 1532(6) and (20)). Pursuant to the ESA and our implementing regulations, the determination of whether a species is threatened or endangered shall be based on any one or a combination of the following five section 4(a)(1) factors: The present or threatened destruction, modification, or curtailment of habitat or range; overutilization for commercial, recreational, scientific, or educational purposes; disease or predation; inadequacy of existing regulatory mechanisms; and any other natural or manmade factors affecting the species' existence (16 U.S.C. 1533(a)(1), 50 CFR 424.11(c)).

ESA-implementing regulations issued jointly by NMFS and USFWS (50 CFR 424.14(b)) define “substantial information” in the context of reviewing a petition to list, delist, or reclassify a species as the amount of information that would lead a reasonable person to believe that the measure proposed in the petition may be warranted. When evaluating whether substantial information is contained in a petition, we must consider whether the petition: (1) Clearly indicates the administrative measure recommended and gives the scientific and any common name of the species involved; (2) contains detailed narrative justification for the recommended measure, describing, based on available information, past and present numbers and distribution of the species involved and any threats faced by the species; (3) provides information regarding the status of the species over all or a significant portion of its range; and (4) is accompanied by the appropriate supporting documentation in the form of bibliographic references, reprints of pertinent publications, copies of reports or letters from authorities, and maps (50 CFR 424.14(b)(2)).

At the 90-day stage, we evaluate the petitioner's request based upon the information in the petition, including its references, and the information readily available in our files. We do not conduct additional research, and we do not solicit information from parties outside the agency to help us in evaluating the petition. We will accept the petitioner's sources and characterizations of the information presented, if they appear to be based on accepted scientific principles, unless we have specific information in our files that indicates the petition's information is incorrect, unreliable, obsolete, or otherwise irrelevant to the requested action. Information that is susceptible to more than one interpretation or that is contradicted by other available information will not be dismissed at the 90-day finding stage, so long as it is reliable and a reasonable person would conclude that it supports the petitioner's assertions. Conclusive information indicating the species may meet the ESA's requirements for listing is not required to make a positive 90-day finding. We will not conclude that a lack of specific information alone negates a positive 90-day finding, if a reasonable person would conclude that the unknown information itself suggests an extinction risk of concern for the species at issue.

To make a 90-day finding on a petition to list a species, we evaluate whether the petition presents substantial scientific or commercial information indicating the subject species may be either threatened or endangered, as defined by the ESA. First, we evaluate whether the information presented in the petition, along with the information readily available in our files, indicates that the petitioned entity constitutes a “species” eligible for listing under the ESA. Next, we evaluate whether the information indicates that the species at issue faces extinction risk that is cause for concern; this may be indicated in information expressly discussing the species' status and trends, or in information describing impacts and threats to the species. We evaluate any information on specific demographic factors pertinent to evaluating extinction risk for the species at issue (e.g., population abundance and trends, productivity, spatial structure, age structure, sex ratio, diversity, current and historical range, habitat integrity or fragmentation), and the potential contribution of identified demographic risks to extinction risk for the species. We then evaluate the potential links between these demographic risks and the causative impacts and threats identified in ESA section 4(a)(1).

Information presented on impacts or threats should be specific to the species and should reasonably suggest that one or more of these factors may be operative threats that act or have acted on the species to the point that it may warrant protection under the ESA. Broad statements about generalized threats to the species, or identification of factors that could negatively impact a species, do not constitute substantial information that listing may be warranted. We look for information indicating that not only is the particular species exposed to a factor, but that the species may be responding in a negative fashion; then we assess the potential significance of that negative response.

Many petitions identify risk classifications made by non-governmental organizations, such as the International Union for the Conservation of Nature (IUCN), the American Fisheries Society, or NatureServe, as evidence of extinction risk for a species. Risk classifications by other organizations or made under other Federal or state statutes may be informative, but such classification alone may not provide the rationale for a positive 90-day finding under the ESA. For example, as explained by NatureServe, their assessments of a species' conservation status do “not constitute a recommendation by NatureServe for listing under the U.S. Endangered Species Act” because NatureServe assessments “have different criteria, evidence requirements, purposes and taxonomic coverage than government lists of endangered and threatened species, and therefore these two types of lists should not be expected to coincide” (http://www.natureserve.org/prodServices/pdf/NatureServeStatusAssessmentsListing-Dec%202008.pdf). Thus, when a petition cites such classifications, we will evaluate the source of information that the classification is based upon in light of the standards on extinction risk and impacts or threats discussed above.

The bigeye thresher shark (Alopias superciliosus) is a large, highly migratory oceanic and coastal species of shark found throughout the world in tropical and temperate seas. In the Western Atlantic (including the Gulf of Mexico), bigeye threshers can be found off the Atlantic coast of the United States (from New York to Florida), and in the Gulf of Mexico off Florida, Mississippi and Texas. They can also be found in Mexico (from Veracruz to Yucatan), Bahamas, Cuba, Venezuela, as well as central and southern Brazil. In the Eastern Atlantic, bigeye threshers are found from Portugal to the Western Cape of South Africa, including the western and central Mediterranean Sea. In the Indian Ocean, bigeye threshers are found in South Africa (Eastern Cape and KwaZulu-Natal), Madagascar, Arabian Sea (Somalia), Gulf of Aden, Maldives, and Sri Lanka. In the Pacific Ocean, from West to East, bigeye threshers are known from southern Japan (including Okinawa), Taiwan (Province of China), Vietnam, between the Northern Mariana Islands and Wake Island, down to the northwestern coast of Australia and New Zealand. Moving to the Central Pacific, bigeye threshers are known from the area between Wake, Marshall, Howland and Baker, Palmyra, Johnston, Hawaiian Islands, Line Islands, and between Marquesas and Galapagos Islands. Finally, in the Eastern Pacific, bigeye threshers occur from Canada to Mexico (Gulf of California) and west of Galapagos Islands (Ecuador). They are also possibly found off Peru and northern Chile (Compagno, 2001).

The bigeye thresher shark possesses an elongated upper caudal lobe almost equal to its body length, which is unique to the Alopiidae family. It has a broad head, a moderately long and bulbous snout, curved yet broad-tipped pectoral fins, distinctive grooves on the head above the gills, and large teeth. The first dorsal fin mid base is closer to the pelvic-fin bases than to the pectoral-fin bases. The caudal tip is broad with a wide terminal lobe. While some of the above characteristics may be shared by other thresher shark species, diagnostic features separating this species from the other two thresher shark species (common thresher, A. vulpinus, and pelagic thresher, A. pelagicus) are their extremely large eyes, which extend onto the dorsal surface of the head, and the prominent notches that run dorso-lateral from behind the eyes to behind the gills. The body can be purplish grey or grey-brown on the upper surface and sides, with grey to white coloring on its underside (light color of abdomen does not extend over pectoral fin bases like common thresher) and no white dot on upper pectoral fin tips like those often seen in common threshers (Compagno 2001).

Bigeye thresher sharks are found in a diverse spectrum of locations, including coastal waters over continental shelves, on the high seas in the epipelagic zone far from land, in deep waters near the bottom on continental slopes, and sometimes in shallow inshore waters. They are an epipelagic, neritic, and epibenthic shark, ranging from the surface and in the intertidal to at least 500 m deep, but mostly below 100 m depth. In our files, we found information indicating that bigeye threshers prefer an optimum swimming depth of 240-360 m, water temperature of 10-16 °C, salinity of 34.5-34.7 ppt, and dissolved oxygen range between 3.0-4.0 ml/l (Cao et al., 2011).

Bigeye threshers feed on small to medium sized pelagic fishes (e.g., lancetfishes, herring, mackerel and small billfishes), bottom fishes (e.g., hake), and cephalopods (e.g., squids). Thresher sharks are unique in that they use their tail in a whip-like fashion to disorient and incapacitate their prey prior to consumption (Oliver, 2013). The arrangement of the eyes, with keyhole-shaped orbits extending onto the dorsal surface of the head, suggest that this species has a dorsal/vertical binocular field of vision (unlike other threshers), which may be related to fixating on prey and striking them with its tail from below (FAO 2015 species fact sheet).

Bigeye thresher sharks have an estimated lifespan of approximately 20-21 years and a maximum total length of about 4.6 m. Maturity in bigeye threshers occurs at 7-13 years and 275-300 cm total length (TL) for males and 8-15 years and 290-341cm (TL) for females. Bigeye threshers have low reproductive capacity of only 2-4 pups per litter (Chen et al., 1997; Compagno, 2001; Moreno and Morón, 1992) and a long gestation period of 12 months, although this remains uncertain due to a lack of birthing seasonality data (Liu et al., 1998). They (like all thresher sharks) are ovoviviparous and oophagous (developing embryo in uteri eat unfertilized eggs produced by the ovary). Size at birth for the bigeye thresher ranges from 64-106 cm TL (Gilmore, 1993), but a mating season has not yet been identified. Bigeye threshers have the slowest population growth rate of all thresher sharks, with an exceptionally low potential annual rate of population increase (0.02; IUCN; λ=1.009 yr−1, Cortés, 2009).

Below we evaluate the information provided in the petition and readily available in our files to determine if the petition presents substantial scientific or commercial information indicating that an endangered or threatened listing may be warranted as a result of any of the factors listed under section 4(a)(1) of the ESA. If requested to list a global population or, alternatively, a DPS, we first determine if the petition presents substantial information that the petitioned action is warranted for the global population. If it does, then we make a positive finding on the petition and conduct a review of the species range-wide. If after this review we find that the species does not warrant listing range-wide, then we will consider whether the populations requested by the petition qualify as DPSs and warrant listing. If the petition does not present substantial information that the global population may warrant listing, but it has requested that we list any distinct populations of the species as threatened or endangered, then we consider whether the petition provides substantial information that the requested population(s) may qualify as DPSs under the discreteness and significance criteria of our joint DPS Policy, and if listing any of those DPSs may be warranted. We summarize our analysis and conclusions regarding the information presented by the petitioners and in our files on the specific ESA section 4(a)(1) factors that we find may be affecting the species' risk of global extinction below.

The petition does not provide a population abundance estimate for bigeye thresher sharks, but points to its “vulnerable” status on the IUCN Red List. The petition asserts that a global decline of bigeye thresher sharks has been caused mainly by commercial and recreational fishing (both direct harvest and bycatch), as evidenced by substantial population declines in every area where sufficient historical and current population data exist. In the Northwest and Western Central Atlantic, the petition cites an 80 percent decline in bigeye thresher sharks since the early 2000s, with an estimated average overall decline of 63 percent since the beginning of data collection in 1986. In the Southwest Atlantic, the petition describes the popularity of bigeye threshers in the Brazilian Santos longline fishery, and asserts that some vessels are directly targeting this species specifically for its fins. The petition also describes consistent gradual decreases in catch per unit effort (CPUE) for this species in the region. The petition describes likely declines of bigeye thresher sharks in the Mediterranean based on declines of other pelagic shark species, including congener A. vulpinus, due to high fishing pressure. In the Indo-West Pacific, the petition cites the prevalence of finning activities, including both legal and extensive illegal directed shark catch in this region, and states that the bigeye thresher in particular is preferentially retained in certain fisheries. In the Eastern Central Pacific, the petition cites 83 percent declines in thresher populations when compared to research surveys from the 1950s. Finally, the petition points to increased interest in recreational fishing of the bigeye thresher shark, with the potential for high post-release mortality. The petition does not provide information on abundance estimates across the global range of the species.

The last IUCN assessment of the bigeye thresher shark was completed in 2009, and several estimates of global and subpopulation trends and status have been made and are described in the following text. In the Northwest Atlantic, declines in relative abundance cited by the petitioner were derived from analyses of logbook data, reported in Baum et al., (2003) and Cortés (2007). The former study analyzed logbook data for the U.S. pelagic longline fleets targeting swordfish and tunas in the Northwest Atlantic, and reported an 80 percent decline in relative abundance for thresher sharks (common and bigeye threshers combined) from 1986 to 2000. The latter study reported a 63 percent decline of thresher sharks (at the genus level) based on logbook data, occurring between 1986 and 2006 (Cortés, 2007). However, the observer index data from the same study (Cortés, 2007) shows an opposite trend in relative abundance, with a 28 percent increase of threshers in the Northwest Atlantic since 1992. Logbook data over the same period (1992-2006) shows a 50 percent decline in thresher sharks. The logbook dataset is the largest available for the western North Atlantic Ocean, but the observer dataset is generally more reliable in terms of consistent identification and reporting. According to observer data, relative abundance of thresher sharks (again, only at the genus level) in the western North Atlantic Ocean appears to have stabilized or even be increasing since the late 1990s (Cortés, 2007). A more recent analysis using logbook data between 1996 and 2005 provides some supporting evidence that the abundance of thresher sharks has potentially stabilized over this time period (Baum and Blanchard, 2010). However, it should be noted that fishing pressure on thresher sharks began over two decades prior to the start of this time series; thus, the estimated declines are not from virgin biomass. Furthermore, the sample size in the latter observer analysis was also very small compared to the previous logbook analyses, which both showed declines. Thus, abundance trend estimates derived from standardized catch rate indices of the U.S. pelagic longline fishery suggest that thresher sharks (both bigeye and common) have likely undergone a decline in abundance in this region. However, the conflicting evidence between logbook and observer data showing opposite trends in thresher shark abundance cannot be fully resolved at this time. Data are not available in the petition or in our own files to assess the trend in population abundance in this region since 2006, or to assess the trend specific to the bigeye thresher shark. Because the logbook data from this region show consistent evidence of a significant and continued decline in thresher sharks, we must consider this information in our 90-day determination. Additionally, in the Southeastern United States, studies show significant declines in the species, with decreases in CPUE indicating that the population of A. superciliosus has declined by 70 percent from historical levels (Beerkircher et al., 2002).

For the Northeast Atlantic, there are no population abundance estimates available, but data indicate that the species is taken in driftnets and gillnets. In the Mediterranean Sea, estimates show significant declines in thresher shark abundance during the past two decades, reflecting data up to 2006. According to historical data compiled using a generalized linear model, thresher sharks have declined between 96 and 99 percent in abundance and biomass in the Mediterranean Sea (Ferretti et al., 2008). Overall, the bigeye thresher shark has been poorly documented in the Mediterranean and is considered scarce or rare.

In the Eastern Central Pacific, logbook data show a historical decline of thresher sharks due to pelagic fishing fleet operations. Trends in abundance and biomass of thresher sharks in the eastern tropical Pacific Ocean were estimated by comparison of pelagic longline research surveys in the 1950s with recent data (1990s); these data were collected by observers on pelagic longline fishing vessels and standardized to account for differences in depth and soak time. This analysis estimated a decline in combined thresher abundance of 83 percent and a decline in biomass to approximately 5 percent of virgin levels (Ward and Myers, 2005).

In other areas of the world, estimates of thresher shark abundance are limited. Bigeye threshers are recorded in the catches of fisheries operating in the Indo-West Pacific, but catches of the species are likely very under-reported. An analysis of purse seine and longline observer data from the Western and Central Pacific produced no clear catch trends for thresher sharks (Alopias spp.); however, shark data from observer data sets are constrained by a lack of observer coverage, particularly for the North Pacific, and for the purse seine fishery by the physical practicalities of onboard sampling (Clarke, 2011). Additionally, this study detected a significant decrease in median size for thresher sharks in tropical areas, most likely reflective of trends in bigeye threshers as they are the most commonly encountered species in this region. While catch data are incomplete and cannot be used to estimate abundance levels or determine the magnitude of catches or trends for bigeye threshers at this time, pelagic fishing effort in this region is high, with reported increases in recent years (IUCN assessment, 2009).

In conclusion, across the species' global range we find evidence suggesting that population abundance of the bigeye thresher shark is declining or, in the Northwest Atlantic Ocean, may be stable at a diminished abundance. While data are still limited with respect to population size and trends, we find the petition and our files sufficient in presenting substantial information on bigeye thresher shark abundance, trends, or status to indicate the petitioned action may be warranted.

The petition indicated three main categories of threats to the bigeye thresher shark: overutilization for commercial, recreational, scientific, or educational purposes; the inadequacy of existing regulatory mechanisms; and other natural or manmade factors affecting its continued existence. We discuss each of these below based on information in the petition, and the information readily available in our files.

The petition states that “the bigeye thresher has shown substantial population declines in every area where sufficient historical and current population data exists” and lists four categories of overutilization: historical, directed, incidental, and recreational. The petition describes historical exploitation as the first category of overutilization for the species, predominantly in the Northwest and Central Atlantic and Eastern Central Pacific. In the Northwest and Central Atlantic, bigeye threshers were historically caught in pelagic longline fisheries. Bigeye threshers have been a prohibited species in all commercial fisheries in the U.S. Atlantic since 2000. Since these regulations became effective in 2000, relative abundance of thresher sharks (again, only at the genus level) in the western North Atlantic Ocean appears to have stabilized or even be increasing since the late 1990s (Baum and Blanchard, 2010; Cortés, 2007). However, it should be noted that bigeye threshers are still caught as bycatch and occasionally landed in the Northwest Atlantic Ocean despite its prohibited status (NMFS, 2012; 2013), which may hinder the ability of the population to rebound from the historical declines.

As previously mentioned, the petition also states that logbook data from the Eastern Central Pacific shows a historical decline of bigeye thresher sharks due to pelagic fishing fleet operations known to take this species. Trends in abundance and biomass of thresher sharks in the eastern tropical Pacific Ocean were estimated by comparison of pelagic longline research surveys in the 1950s with recent data (1990s); these data were collected by observers on pelagic longline fishing vessels and standardized to account for differences in depth and soak time. For example, in the 1990's, longliners deployed more hooks (averaging 2240 hooks per day compared to 322 hooks in the 1950s) over a wider depth range (down to 600 m compared to 200 m) for longer periods. Thus, while catches of thresher sharks increased (from 112 threshers in the 1950s survey to 511 threshers in the 1990s survey), this analysis estimated a decline in combined thresher abundance of 83 percent, with a decline in mean biomass to approximately 5 percent of virgin levels and a decline in mean body mass from 17 kg to 12 kg). While this analysis was not species-specific (Ward and Myers, 2005), we must consider this information in our 90-day finding given the potential significant population decline of bigeye threshers in this region.

In addition to broad commercial harvest of the species, the petition states that direct catch related to the shark fin trade has resulted in population decline, and that bigeye thresher sharks are targeted and preferentially retained for their fins. For example, the petition stated in the Indo-West Pacific, a single thresher fin can fetch US $250, creating incentives that would drive overutilization. However, this statement is not entirely correct. While it is true that high prices are paid for thresher sharks, the value of US $250 was not for a single fin, but rather for the entire shark (Gilman et al., 2007). Still, in comparison to other sharks (e.g., shortfin mako only fetches US $50 per shark), thresher sharks appear to be highly valued and consequently targeted for both their meat and fins. While the petition did not provide any information connecting population declines as a result of this direct catch, evidence suggests that the three thresher shark species, collectively, may account for approximately 2.3 percent of the fins auctioned in Hong Kong, the world's largest fin-trading center (Clarke, 2006). This translates to 0.4 million to 3.9 million threshers that may enter the global fin trade each year (Clarke, 2006), with bigeye thresher having the highest value and vulnerability to fishing compared to the other thresher species (Cortés, 2010); still, the relative proportion of each thresher shark species comprising the shark fin trade is not available in this genus-level assessment and information on the species-specific impact of this harvest on bigeye thresher shark abundance is not provided by the petitioner. However, we found species-specific evidence in our files that bigeye threshers may be highly utilized in the shark fin trade. In a genetic barcoding study of shark fins from markets in Taiwan, bigeye threshers were one of 20 species identified and comprised 0.07 percent of collected fin samples. Additionally, thresher sharks comprised 15 percent of fins genetically tested from markets throughout Indonesia (the largest shark catching country in the world), with bigeye threshers making up an estimated 7.6 percent of all fins tested. The high frequency of bigeye threshers in the markets across Indonesia provides some evidence that they are not just caught incidentally, but are targeted by large-scale fisheries (Sembiring, 2015). In another genetic barcoding study of fins from United Arab Emirates, the fourth largest exporter in the world of raw dried shark fins to Hong Kong, the authors found that the Alopiidae family represented 5.9 percent of the trade from Dubai, with bigeye thresher comprising 2.31 percent (Jabado et al., 2015). Overall, evidence that bigeye thresher sharks (and threshers in general) are highly valued for their fins, are possibly targeted in some areas, and comprise a portion of the Hong Kong fin-trading auction suggests that this threat may impact the species.

In the Indian Ocean, the status and abundance of shark species is poorly known despite a long history of research and more than 60 years of commercial exploitation by large-scale tuna fisheries (Romanov et al., 2010). Pelagic sharks, including bigeye threshers, are targeted in various fisheries, including semi-industrial, artisanal, and recreational fisheries. Countries that fish for various pelagic species of sharks include: Egypt, India, Iran, Oman, Saudi Arabia, Sudan, United Arab Emirates, and Yemen, where the probable or actual status of shark populations is unknown, and Maldives, Kenya, Mauritius, Seychelles, South Africa, and United Republic of Tanzania, where the actual status of shark populations is presumed to range from fully exploited to over-exploited (Young, 2006). In 2013, an Ecological Risk Assessment (ERA) was developed by the Indian Ocean Tuna Commission (IOTC) Scientific Committee to quantify which shark species are most at risk from the high levels of pelagic longline fishing pressure. In this ERA, the IOTC Scientific Committee noted that A. superciliosus received a high vulnerability ranking (No. 2) for longline gear, as the species is characterized as one of the least productive shark species, and is highly susceptible to catch in longline fisheries. The ERA also noted that the available evidence indicates considerable risk to the status of the Indian Ocean Alopias spp. stocks at current catch levels, which, from 2000-2011 was estimated to be 22,811 mt (Merua et al., 2013).

Indirect catch is another category of overutilization identified by the petition, which states that post-release mortality may be high in the species. However, no information is provided in the petition to connect the effect of bycatch on population declines of the species. In the Northeast Atlantic and Mediterranean, while there are no target fisheries for thresher sharks, they are taken as bycatch in various fisheries, including the Moroccan driftnet fishery in the southwest Mediterranean. They are also caught by industrial and semi-industrial longline fisheries and by artisanal gillnet fisheries. In our files, we found evidence that in the last two decades, thresher sharks (common and bigeye) have declined between 96 and 99 percent in abundance and biomass in the Mediterranean Sea (Ferretti, 2008).

Although bigeye thresher sharks have been a prohibited species in U.S. Atlantic commercial fisheries since 2000, they are still incidentally taken as bycatch on pelagic longlines and in gillnets on the East Coast. For example, in our files, we found that since the prohibition on bigeye threshers came into effect in 2000, approximately 1,493 lbs, dressed weight (677 kg) of bigeye thresher were landed in the Atlantic (NMFS, 2012; 2014) despite its prohibited status. In 2010, the United States reported that bigeye thresher represented the second largest amount of dead discards in the Atlantic commercial fleet, reporting a total of 46 t (NOAA, 2010 Report to ICCAT). In 2011, this number dropped to 27 t of bigeye thresher dead discards (NOAA, 2011 Report to ICCAT). Further, several recent reports assessing the vulnerability of bigeye threshers and other pelagic sharks to bycatch in the U.S. Atlantic pelagic longline fishery characterized the bigeye thresher as highly vulnerable (Cortes, 2010; Cortes, 2012; Gallagher et al., 2014). These landings and dead discards may be linked to declines in the species across the Northwest Atlantic portion of its range; however, as discussed earlier, conflicting logbook and observer data decrease the certainty of these trends (Cortés, 2007; Baum and Blanchard, 2010).

In the Southwest Atlantic Ocean, off the coast of Brazil, bigeye threshers represent almost 100 percent of thresher sharks caught in longline fisheries (Amorin, 1998). The landed catch and CPUE of bigeye thresher shark in this fishery increased from 1971 to 1989, and then gradually decreased from 1990 to 2001; however, this does not necessarily reflect stock abundance because changes in the depth of fishing operations also occurred, which may have affected the time series. Thus, further information is needed to resolve this. In our files, we found that bigeye threshers are also taken in Uruguayan longline fisheries at similar levels. In one study, observer data from 2001-2005 recorded a total of 295 A. superciliosus specimens, in which the species' abundance was characterized as “low” despite high fishing effort (Berrondo et al., 2007). Further, observer data from 1992-2000 showed that bigeye threshers experience high mortality in longline fisheries in the Southwest Atlantic, with 54 percent dead upon capture (Beerkircher et al., 2002). Given the declines reported in other areas for which data are available throughout other parts of the species' range and the high fishing pressure from fleets throughout the Southwest Atlantic, A. superciliosus may be experiencing a level of exploitation in this part of its range that may increase its risk of extinction.

In the Eastern Central Pacific, the petition points to the fact that bigeye threshers have been recorded as bycatch in purse seine fleets operating in this region, in which bigeye threshers comprised 1 percent of shark species caught during a Shark Characteristics Sampling Program conducted from 1994-2004 (Roman-Verdesoto and Orozco-Zöller, 2005). Bycatch for this report was defined as sharks that were discarded dead after being removed from the net and placed on the vessel. Since 2010, catches of thresher sharks in this fishery have fluctuated between 10 t and 14 t; however, in a preliminary productivity-susceptibility assessment, bigeye threshers were characterized as having a low susceptibility to this fishery (IAATC, 2009). Complete bycatch and discard data are not readily available from longline fleets in the Eastern Pacific. In our files, we found that bigeye thresher sharks are minor components of U.S. West Coast fisheries, taken incidentally and presumably not overexploited, at least locally. The bigeye thresher occurs regularly but in low numbers, comprising only approximately 9 percent of common thresher catch (PFMC, 2003). Overall, we found that apart from blue and silky sharks, there are no stock assessments available for shark species in the Eastern Pacific, and hence the impacts of bycatch on the population are unknown (IATTC, 2014). However, despite a lack of information regarding present levels of bycatch occurring in other fisheries throughout the Eastern Pacific, as described earlier, thresher sharks were estimated to have experienced an 83 percent decline in this part of the species' range as a result of fishing mortality in longline fisheries. Given the high rates of bycatch-related mortality observed in this species throughout other parts of its range (e.g., Northwest and Southwest Atlantic, Indian Ocean, and Central Pacific), it is likely the species experiences similar rates of bycatch-related mortality in this part of its range as well. Thus, it is likely that the historical and continued levels of exploitation in this part of the species' range are impacting the species, such that listing may be warranted.

We found evidence that bigeye threshers are known to interact with longline fisheries throughout the Indo-Pacific. In the Western and Central Pacific, where sharks represent 25 percent of the longline fishery catch, observer data showed that bigeye thresher shark is the 7th most commonly bycaught species of shark out of a total 49 species reported by observers (Molony, 2007). We found that bigeye threshers are commonly taken as bycatch in longline fisheries in the Republic of the Marshall Islands, in which they exhibit at-vessel and/or post-release mortality of 50 percent, and nearly 99 percent are finned and subsequently discarded (Bromhead, 2012). Further, in a species status snapshot for thresher sharks in the Western and Central Pacific, Clarke et al., (2011) identified significant decreasing size trends for thresher sharks in tropical areas, which may be indicative of population declines in these areas. It is thought that these findings most likely reflect trends of bigeye threshers as they are the most common thresher species encountered in this region, with catches of common and pelagic threshers characterized as rare or uncommon. Bigeye threshers are also commonly caught by Hawaii longline fisheries, particularly on deep-set gear (Walsh et al., 2009), and represented 4.1 percent of shark catches from 1995-2006. While catches of thresher sharks (Alopias spp.) have trended upward, actual landings of thresher sharks in Hawaii have decreased from 50 mt in 2001 to 16 mt in 2010, presumably due to the implementation of state and Federal laws regarding shark finning (NMFS, 2011).

In the Indian Ocean, while fisheries are directed at other species, bigeye threshers are commonly caught as bycatch and catch rates are considered high (IOTC, 2011; Hererra and Pierre, 2011). For example, bycatch of bigeye threshers has been recorded in Japanese and Taiwanese longline fisheries. According to Japanese observer data, 162 bigeye threshers were bycaught in 6 months (from July 2010 to January 2011). These data do not include live-released bigeye thresher sharks (Ardill et al., 2011), which reportedly have high post-release mortality rates (IOTC, 2014). Observer data from Taiwanese longline fleets (with coverage ranging from only 2.2 percent in 2004 to 20.8 percent in 2007) recorded a total of 445 bigeye threshers bycaught from 2004-2008, with approximately 61 percent discarded (Huang and Liu, 2010). Hooking mortality is apparently very high in this region; therefore, the IOTC's regulation 10/12 that prohibits the onboard retention of any part of any thresher species and promotes live release of thresher sharks may be ineffective for the conservation of bigeye thresher sharks. For example, in the Portuguese longline fleet, bigeye threshers experienced a high rate of at-vessel mortality of 68.4 percent (n = 19) from May to September 2011 (Ardill et al., 2011). The IOTC reported in 2014 that “maintaining or increasing effort in this region will probably result in further declines in biomass, productivity and CPUE” for bigeye threshers (IOTC, 2014).

Overall, there is considerable uncertainty regarding the actual levels of bycatch of bigeye thresher shark occurring throughout its range; however, it is likely that these rates are significantly under-reported due to a lack of comprehensive observer coverage in areas of its range in which the highest fishing pressure occurs, as well as a tendency for fishers to not record discards in fishery logbooks. Nevertheless, given the prevalence of bigeye threshers as incidental catch throughout its range and the species' observed high hooking and post-release mortality rates, combined with the species' low productivity, bycatch-related fishing mortality may be a threat placing the species at an increased risk of extinction.

The petition identified recreational fishing as the fourth category of overutilization. In our files, we found evidence that thresher sharks, particularly common threshers, are valued by recreational sport fishermen throughout the species' U.S. East Coast and West Coast range; however, bigeye threshers do not appear to be as important in recreational fisheries and are largely prohibited in many fisheries within the United States. The petition described results from Heberer (2010), which identified the potential negative impact of recreational fishing on the survival of congener, A. vulpinus, by assessing post-release survivorship of sharks captured using the caudal fin-based techniques used by most recreational fishermen in southern California. As previously described, thresher sharks use their elongate upper caudal lobe to immobilize prey before it is consumed, and the majority of common thresher sharks captured in the southern California recreational fishery are hooked in the caudal fin and hauled-in backwards. This is significant because common threshers are obligate ram ventilators that require forward motion to ventilate the gills (Heberer, 2010), and the reduced ability to extract oxygen from the water during capture, as well as the stress induced from these capture methods, may influence recovery following release. The findings of Heberer (2010) demonstrate that large tail-hooked common thresher sharks with prolonged fight times (≥85 min) exhibit a heightened stress response, which may contribute to an increased mortality rate. This work suggests, especially for larger thresher sharks, that recreational catch-and-release may not be an effective conservation-based strategy for the species. A recent paper by Sepulveda (2014) found similar evidence for high post-release mortality of recreationally caught common thresher sharks in the California recreational shark fishery. Their results demonstrated that caudal fin-based angling techniques, which often result in trailing gear left embedded in the shark, can negatively affect post-release survivorship. This work suggests that mouth-based angling techniques can, when performed properly, result in a higher survivorship of released sharks. The petition argues that because common thresher sharks may exhibit high mortality in recreational fisheries that bigeye threshers would likely exhibit similar results. While this may be true, in our files, we found no evidence to suggest that bigeye threshers are declining (or responding in a negative fashion) as a result of utilization by recreational fisheries. While it is not known if this species enters the California recreational fishery on any regular basis, presumably only few are taken. Further, there are no records from the recreational fishery off Oregon or Washington (NMFS, 2007), and in fact, fishing of all thresher species is prohibited in Washington. Likewise, in the Northwest Atlantic, bigeye threshers have been prohibited in recreational fisheries by Federal regulations since 1999. Further, U.S. states from Maine to Florida have adopted the Interstate Fisheries Management Plan (FMP) for Atlantic Coastal Sharks adopted by the Atlantic States Marine Fisheries Commission (ASMFC), which prohibits recreational fishing of bigeye threshers. Finally, since prohibition of this species was implemented in 1999, there has been no observed recreational harvest of this species, with the exception of years 2002 and 2006 (NMFS, 2014). The petition did not provide, nor could we find in our files, any information regarding the threat of recreational fishing to bigeye threshers throughout the rest of the species' range. Thus, we find that the information presented in the petition, and in our files, does not comprise substantial information that would lead us to conclude the species may have an increased risk of extinction from overutilization as a result of recreational fishing activities.

Overall, trends in the North West and Central Atlantic Ocean suggest that the species experienced historical declines from overexploitation, but may be stabilized and possibly increasing in recent years, although there is considerable uncertainty regarding these trends. Elsewhere across the species' range, information in the petition and in our files suggests that the species may continue to experience declines as a result of overutilization from both direct and indirect fishing pressure. In summary, the petition, references cited, and information in our files comprise substantial information indicating that listing may be warranted because of overutilization for commercial purposes.

The petition points to “virtually non-existent international regulatory protections” to assert that bigeye threshers qualify for listing due to the inadequacy of existing regulatory mechanisms. For example, the petition mentions the lack of protections from the Convention on International Trade of Endangered Species (CITES) for the bigeye thresher shark, but then states that even if the species was listed under CITES, it would still be inadequate due to the fact that a CITES listing would only address threats associated with the international trade of the species, and would not address such impacts as bycatch. Although a CITES Appendix II listing or international reporting requirements would provide better data on the global catch and trade of the bigeye thresher shark, the lack of a CITES listing or requirements does not suggest that current regulatory mechanisms are inadequate to protect the bigeye thresher shark population from becoming threatened or endangered under the ESA. The petition also asserts that the recent listing of bigeye thresher shark under Appendix II of the Convention of Migratory Species (CMS) is also inadequate given that the United States and other range states are not Member Parties to CMS and are therefore not bound by the requirements imposed by the Appendix II listing. The petition further states that the Convention text is only suggestive and not self-executing upon the listing of a species. On the contrary, we find that a CMS Appendix II listing now encourages international cooperation towards conservation of the species, and although the United States is not currently a party to CMS, the United States is a signatory to a number of CMS instruments for the conservation of various marine species, including sharks.

The petition also asserts that finning regulations and species-specific retention bans are “inadequate” for protecting the bigeye thresher shark species because they may still be caught, either directly or indirectly. The petition also cites several regional fisheries management organizations (RFMOs) that implement a 5 percent fin-to-carcass ratio regulation, describes what the petitioner contends are potential loopholes in those regulations, and states that these general regulations are inadequate for the bigeye thresher shark, whose larger fins make it a more targeted species. The petition further contends that species-specific retention bans for bigeye threshers, such as the ones implemented by ICCAT and IOTC that specifically prohibit the retention, transshipping, landing, storing, selling, or offering for sale any part or whole carcass of bigeye thresher sharks, are also inadequate largely because they do not address incidental catch and subsequent high mortality rates of the species. Based on the information presented in the petition and in our files, we find that the bigeye thresher shark is highly valued for its fins, and can be identified in the shark fin market at the species level. While regulations banning the finning of sharks are a common form of shark management and have been adopted by far more countries and regional fishery management organizations than the petition lists (see HSI, 2012), we agree with the petition that due to high rates of hooking mortality observed in this species as a result of incidental catch, prohibitions on the retention of bigeye thresher or restrictions on the finning of sharks may not be adequate to protect the bigeye thresher from fishing mortality rates that may contribute to its extinction risk, especially given the species' significantly low productivity and intrinsic rate of population increase.

In addition to the inadequacy of international regulations, the petition states that “while the U.S. has attempted to protect the bigeye thresher shark in U.S. waters, piecemeal protections that fail to cover the species throughout its migratory range have proven to be unsuccessful.” Though U.S. regulations by their jurisdictional nature only cover U.S. fishers, we do not agree that this makes them inadequate. We find that U.S. national fishing regulations include numerous regulatory mechanisms for both sharks in general, and bigeye threshers specifically, that may help protect the species. For example, in the U.S. Atlantic, the bigeye thresher has been a prohibited species in both commercial and recreational fisheries since 2000 and 1999, respectively, under the 1999 Fishery Management Plan for Atlantic Tunas, Swordfish, and Sharks. In addition, current management measures for the Atlantic shark fisheries include the following: commercial quotas, commercial retention limits, limited entry, time-area closures, and recreational bag limits. Sharks are required to be landed with fins naturally attached to the carcass. Additionally, several U.S. states have prohibited the sale or trade of shark fins/products as well, including Hawaii, Oregon, Washington, California, Illinois, Maryland, Delaware, New York, and Massachusetts, subsequently decreasing the United States' contribution to the fin trade. For example, after the state of Hawaii prohibited finning in its waters in 2000 and required shark fins to be landed with their corresponding carcasses in the state, shark fin imports from the United States into Hong Kong declined significantly (54 percent decrease, from 374 to 171 tonnes), as Hawaii could no longer be used as a fin trading center for the international fisheries operating and finning in the Central Pacific (Miller, 2014). Except for smooth dogfish (Mustelus canis), the U.S. Shark Conservation Act of 2010 protects all shark species, making it illegal to remove any of the fins of a shark (including the tail) at sea; to have custody, control, or possession of any such fin aboard a fishing vessel unless it is naturally attached to the corresponding carcass; to transfer any such fin from one vessel to another vessel at sea, or to receive any such fin in such transfer, without the fin naturally attached to the corresponding carcass; or to land any such fin that is not naturally attached to the corresponding carcass, or to land any shark carcass without such fins naturally attached. However, we do agree with the petition that these regulations do not address the issue of bycatch-related mortality of the species, especially considering the fact that bigeye threshers are still bycaught in U.S. fisheries.

Overall, while measures may be implemented to reduce bycatch, we found no evidence that these measures have been incorporated into common practice throughout the species' range, particularly in areas where fishing pressure is most concentrated. Further, while numerous finning and species-specific retention bans have been implemented, these regulations fail to address the species' high rate of bycatch-related mortality. In summary, the petition, references cited, and information in our files comprise substantial information indicating that the species may be impacted by the inadequacy of regulatory mechanisms in parts of its range, such that listing may be warranted.

The petition states that the biological constraints of the bigeye thresher shark, such as its low reproduction rate (typically 2-4 pups a year), coupled with a late age of maturity (approximately 12-14 years for females, and slightly earlier for males, between 9-10 years) contribute to the species' vulnerability to harvesting and its inability to recover rapidly. We agree with the petition that the bigeye thresher shark exhibits relatively slow growth rates and low fecundity. An ecological risk assessment conducted to inform the International Commission for the Conservation of Atlantic Tunas (ICCAT) categorized the relative risk of overexploitation of the 11 major species of pelagic sharks, including the bigeye thresher shark (Cortés et al., 2010, 2012). The study derived an overall vulnerability ranking for each of the 11 species, which was defined as “a measure of the extent to which the impact of a fishery [Atlantic longline] on a species will exceed its biological ability to renew itself” (Cortés et al., 2010, 2012). This robust assessment found that bigeye thresher sharks have a combination of low productivity and high susceptibility to pelagic longline gear, which places the bigeye thresher at high risk of overexploitation to the combined pelagic longline fisheries in the Atlantic Ocean (Cortés et al., 2010, 2012). In fact, of the 11 species examined in this study, Atlantic bigeye thresher sharks were identified as one of the most vulnerable and least productive shark species. Even within the genus Alopias, the bigeye thresher shark has the slowest population growth rate of all thresher sharks, with an exceptionally low potential annual rate of population increase (0.002-0.009 or 1.6 percent) under sustainable exploitation (Cortés, 2008; Dulvy et al., 2008; Smith et al., 2008). This makes them particularly vulnerable to any level of fisheries exploitation, whether targeted or caught as bycatch in fisheries for other species. Given that bigeye thresher sharks are caught regularly as incidental bycatch throughout its range and experience high mortality rates as a result, and that the species may be targeted in some areas for its fins, the species' growth and reproductive factors may inhibit the species' ability to recover from even moderate levels of exploitation, thus placing the bigeye thresher shark at an increased risk of extinction as a result. In summary, the petition, references cited, and information in our files comprise substantial information indicating that the species is impacted by “other natural or manmade factors,” including the life history trait of slow productivity, such that listing the species may be warranted.

We conclude that the petition does not present substantial scientific or commercial information indicating that the ESA section (4)(a)(1) threats of “present or threatened destruction, modification, or curtailment of its habitat or range” or “disease or predation” may be causing or contributing to an increased risk of extinction for the global population of the bigeye thresher shark. However, we do conclude that the petition and information in our files present substantial scientific or commercial information indicating that the section 4(a)(1) factor “overutilization for commercial, recreational, scientific, or educational purposes,” as well as “inadequacy of existing regulatory mechanisms” and “other manmade or natural factors,” may be causing or contributing to an increased risk of extinction for the species.

Based on the above information and the criteria specified in 50 CFR 424.14(b)(2), we find that the petition and information readily available in our files present substantial scientific and commercial information indicating that the petitioned action of listing the bigeye thresher shark worldwide as threatened or endangered may be warranted. Therefore, in accordance with section 4(b)(3)(A) of the ESA and NMFS' implementing regulations (50 CFR 424.14(b)(3)), we will commence a status review of the species. During the status review, we will determine whether the species is in danger of extinction (endangered) or likely to become so within the foreseeable future (threatened) throughout all or a significant portion of its range. We now initiate this review, and thus, we consider the bigeye thresher shark to be a candidate species (69 FR 19975; April 15, 2004). Within 12 months of the receipt of the petition (April 27, 2016), we will make a finding as to whether listing the species as endangered or threatened is warranted as required by section 4(b)(3)(B) of the ESA. If listing the species is found to be warranted, we will publish a proposed rule and solicit public comments before developing and publishing a final rule.

To ensure that the status review is based on the best available scientific and commercial data, we are soliciting information relevant to whether the bigeye thresher shark is endangered or threatened. Specifically, we are soliciting information in the following areas: (1) Historical and current distribution and abundance of this species throughout its range; (2) historical and current population trends; (3) life history in marine environments, including identified nursery grounds; (4) historical and current data on bigeye thresher shark bycatch and retention in industrial, commercial, artisanal, and recreational fisheries worldwide; (5) historical and current data on bigeye thresher shark discards in global fisheries; (6) data on the trade of bigeye thresher shark products, including fins, jaws, meat, and teeth; (7) any current or planned activities that may adversely impact the species; (8) ongoing or planned efforts to protect and restore the species and its habitats; (9) population structure information, such as genetics data; and (10) management, regulatory, and enforcement information. We request that all information be accompanied by: (1) Supporting documentation such as maps, bibliographic references, or reprints of pertinent publications; and (2) the submitter's name, address, and any association, institution, or business that the person represents.

A complete list of references is available upon request to the Office of Protected Resources (see ADDRESSES).

The authority for this action is the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).