SUPPLEMENTARY INFORMATION:

Background

The MMPA prohibits the “take” of marine mammals, with certain exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) direct the Secretary of Commerce ( printed page 28444) (as delegated to NMFS) to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are promulgated and a LOA is issued or an incidental harassment authorization (IHA) is issued.

Authorization for incidental takings shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for taking for subsistence uses (where relevant). If such findings are made, NMFS must prescribe the permissible methods of taking and other “means of effecting the least practicable adverse impact” on the affected species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of the species or stocks for taking for certain subsistence uses (referred to in shorthand as “mitigation”); and set forth requirements pertaining to the monitoring and reporting of the takings. The definitions of applicable MMPA statutory terms are provided directly below or included in the relevant sections of this rule.

• U.S. citizen —individual U.S. citizens or any corporation or similar entity if it is organized under the laws of the United States or any governmental unit defined in 16 U.S.C. 1362(13); 50 CFR 216.103;
• Take —to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal (16 U.S.C. 1362(13));
• Incidental harassment, incidental taking, and incidental, but not intentional, taking —an accidental taking. This does not mean that the taking is unexpected, but rather it includes those takings that are infrequent, unavoidable or accidental (50 CFR 216.103);
• Level A harassment —any act of pursuit, torment, or annoyance which has the potential to injure a marine mammal or marine mammal stock in the wild (16 U.S.C. 1362(18); 50 CFR 216.3); and
• Level B harassment —any act of pursuit, torment, or annoyance which has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering (16 U.S.C. 1362(18); 50 CFR 216.3).

Purpose of Regulatory Action

NMFS received an application from the IBRP requesting 5-year regulations and a LOA issued thereunder to take individuals of three species (California sea lion, Steller sea lion, and harbor seal), comprising three stocks of marine mammals, by Level A harassment and Level B harassment incidental to the IBRP's activities. No serious injury or mortality is anticipated or authorized. Please see the Background section for definitions of harassment.

These regulations, promulgated under the authority of the MMPA (16 U.S.C. 1361 et seq.), provide a framework for authorizing the take of marine mammals incidental to construction activities associated with the IBR Project, including impact and vibratory pile driving. The regulations include mitigation, monitoring, and reporting requirements. These requirements, which were proposed by IBRP, are expected to minimize the number and/or intensity of incidents of marine mammal take, as well as to provide information to better understand the impacts of the action and document compliance. IBRP has agreed that all of the mitigation measures are practicable. As required by the MMPA, NMFS concurred that these measures are sufficient to achieve the least practicable adverse impact on the affected marine mammal species or stocks and their habitat.

Legal Authority for the Action

Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs the Secretary of Commerce to allow, upon request, the incidental, but not intentional taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region for up to 5 years if, after notice and public comment, the agency makes certain findings and promulgates regulations that set forth permissible methods of taking pursuant to that activity and other means of effecting the “least practicable adverse impact” on the affected species or stocks and their habitat (see the discussion below in the Mitigation section), as well as monitoring and reporting requirements. Section 101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR part 216, subpart I provide the legal basis for issuing this rule containing 5-year regulations and a 5-year LOA.

Summary of Major Provisions Within the Rule

Following is a summary of the major provisions of this rule regarding the IBRP's activities. These measures include:

• Prescribing permissible methods of taking of small numbers of marine mammals by Level A harassment and/or Level B harassment incidental to the IBR Project;
• Required monitoring of the construction areas to detect the presence of marine mammals before beginning construction activities;
• Establishment of shutdown zones;
• Bubble curtains required for impact driving of steel piles except as necessary to verify bubble curtain effectiveness during hydroacoustic monitoring;
• Soft start for impact pile driving to allow marine mammals the opportunity to leave the area prior to beginning impact pile driving at full power;
• Submittal of monitoring reports including a summary of marine mammal species and behavioral observations, construction shutdowns or delays, and construction work completed; and
• Hydroacoustic monitoring to verify effectiveness of noise attenuation devices and sound source level assumptions for modeling.

Through adaptive management, the regulations allow NMFS Office of Protected Resources to modify ( e.g., remove, revise, or add to) the existing mitigation, monitoring, or reporting measures summarized above and required by the LOA.

Summary of Request

On July 18, 2024, NMFS received an application from the IBRP requesting authorization for take of marine mammals incidental to construction activities related to the IBR Project on I-5 between Portland, OR, and Vancouver, WA. After the IBRP responded to our questions on October 12, 2024, and January 14, 2025, we determined the application was adequate and complete on January 16, 2025. We published a notice of receipt in the Federal Register on March 13, 2025 (90 FR 11950, March 13, 2025) and received 38 comments. Of these, 37 were opposed to the IBR Project; most suggested an alternative project design unrelated to IBRP's request for incidental take authorization, and which are outside the scope of NMFS' action in promulgating regulations under the MMPA because the design of the project is at the discretion of the IBRP. One comment letter expressed support for the IBR Project and the potential associated ( printed page 28445) increases in employment and training opportunities for ironworkers. NMFS determined that these comments did not provide information relevant to our decision under the MMPA. On August 19, 2025, NMFS published a proposed rule (90 FR 40492) (Proposed Rule) and a request for public comments in the Federal Register ; we received three total comments on the proposed rule, none of which were relevant to our findings due to a lack of substantive information provided or because the comments were on issues outside the scope of NMFS' action ( i.e., on the project's design).

Changes From the Proposed to Final Rule

There have been several changes from the proposed rule in this final rule. First, in the Estimated Take of Marine Mammals section (table 10 of the Proposed Rule; table 3 of this final rule), the proxy source levels for vibratory driving have been adjusted. This minor change was made to account for the discrepancy between measured and assumed values noted in footnote 4 of table 10 in the Proposed Rule. Specifically, single-hammer vibratory driving proxy source levels have been revised from 175 decibels (dB) root mean square (RMS) re 1 micropascal (µPa) to 170 dB RMS re 1 µPa and associated proxy sound levels (for simultaneous vibratory driving of two piles) have been adjusted from 178 dB RMS to 173 dB RMS, following the methodology outlined in the Proposed Rule for additive sources. The associated Level A and Level B harassment isopleths have been recalculated and are shown in table 4 of this final rule. These changes are small and result in no impact to the estimated take of marine mammals because of the curvature of the river restricting the propagation of sound up and downstream. There were small reductions to the AUD INJ harassment zone isopleths and ensonified areas that are shown in table 3 of this rule.

Secondly, proxy sound levels (dB peak) for simultaneous impact driving of two 24-inch (in) piles and for two 48-in piles were incorrectly calculated in the proposed rule. They have been corrected; these are now 201 dB peak and 210 dB peak, respectively. The RMS and single-strike sound exposure level (SEL_ss) values shown in the proposed rule were correct and have not changed, and no changes were made to the resulting Level A or Level B harassment zone isopleths and associated estimates of exposures.

Thirdly, the Proposed Monitoring and Reporting section of the Proposed Rule and section 217.146(e)(v) of the proposed regulatory text incorrectly included hydroacoustic monitoring of vibratory pile driving; this language has been removed from the final rule. The inclusion of hydroacoustic monitoring for vibratory pile driving was purely a clerical error; monitoring of impact driving is required under the applicant's U.S. Army Corps of Engineers consultation due to potential injurious take of endangered salmonid fishes. Vibratory driving has no potential for injurious take of fishes, and thus no hydroacoustic monitoring is required under that consultation. Hydroacoustic monitoring of impact driving is planned and remains included in this final rule.

Finally, in the regulatory text, the following changes were made: all of section 217.145(a)(4)(ii), and part of section 217.145(a)(6)(iii) were deleted to remove confusion about whether the shutdown zone must be fully visible in order to be effectively monitored during short periods of adverse weather conditions; section 217.145(a)(6)(v) was deleted to reduce redundancy in the regulatory text with section 217.145(a)(3); and section 217.147(c) was deleted because the LOA as issued is valid for the duration of the effective dates. Additionally, § 217.146(d)(4) of the proposed rule was missing a standard requirement to report the number of marine mammals detected within the harassment zones, by species. This language has been added to the regulatory text (§ 217.146(d)(4)(ix)) and the associated LOA. Other clerical errors such as numbering were corrected and clerical changes corresponding to the substantive changes described above were made as needed.

Description of Specified Activity

Overview

The IBR Project will improve I-5 corridor mobility by addressing present and future travel demand and mobility needs in the IBR Project area. The project consists of multiple components and interchanges, extending from approximately Columbia Boulevard in the south to State Route (SR) 500 in the north; one component of the project is to replace the existing bridges over the Columbia River and North Portland Harbor to accommodate increasing travel demand and congestion, improve safety related to traffic accidents, and reduce vulnerability to seismic events. The existing bridges do not meet current seismic standards and are vulnerable to failure in an earthquake. The IBR Project is anticipated to take approximately 9 to 15 years to complete and will require in-water work in up to 9 construction seasons. These regulations are effective for the first 5 construction years (2027-2032). IBRP anticipates requesting additional future incidental take authorizations as necessary in association with subsequent years of construction.

Exact project sequencing is still in development; however, it is currently anticipated that work to be conducted during the first 5 years of the IBR Project will include construction of the new Columbia River Bridge and associated approaches, and construction of the transit bridge crossing the North Portland Harbor. In-water pile driving for the first 5 construction years will include both impact and vibratory driving of temporary steel pipe (24- in (0.61 meters (m)) and 48-in (1.2 m) diameter) and steel sheet piles. Permanent bridge foundations will be constructed using 10-foot (ft) (3-m) diameter steel casings installed with an oscillator, analogous to a rotary drill. Impact driving would be conducted primarily with the use of a bubble curtain, with a minimal amount of unattenuated driving to confirm bubble curtain effectiveness. In-water pile driving associated with the project will include installation and potential removal of approximately 1,560 temporary steel pipe piles, and 1,500 linear ft (457 m) of steel sheet piles over the 5-year period.

Dates and Duration

IBRP anticipates that in-water construction activities associated with this project will begin on September 15, 2027, and extend through September 14, 2032. In-water pile installation for the first 5 years of the IBR Project is expected to occur on approximately 1,725 non-consecutive days. While the exact project design and sequence of construction are not yet finalized, in-water project elements and estimated durations are shown in table 1. Land-based project elements do not have the potential to cause take of marine mammals; for a description and information on the duration of land-based elements, please see the Proposed Rule. Construction timing, sequencing, and duration are dependent on funding, design assumptions, contractor schedules and equipment, and weather, among other factors. The duration estimates shown are based on the best available information at the time of publication of this final rule; however, the schedule may shift such that actual activities occur in different years than specified below.

Impact driving will be restricted to an in-water work window between September 15 and April 15 of each year. ( printed page 28446) This window was determined via coordination with state (Oregon Department of Fish and Wildlife (ODFW) and Washington Department of Fish and Wildlife (WDFW)) and Federal (U.S. Army Corps of Engineers, Federal Highway Administration, Federal Transit Administration, and NMFS) agencies, Tribal parties, and public input to reduce potential impacts to Endangered Species Act (ESA)-listed fishes. Vibratory pile driving will occur year-round.

Specified Geographical Region

The IBR Project will replace the bridge spans across the Columbia River and North Portland Harbor and the associated highway interchanges on an approximately 5-mile (mi) (8 kilometer (km)) stretch of I-5 between Portland, OR, and Vancouver, WA (figure 1). In-water work will occur in the subset of the IBR Project area between the north bank of the Columbia River in Washington and the south shore of the North Portland Harbor in Oregon, between river miles 106 and 107. The widths of the Columbia River and North Portland Harbor at this location are approximately 0.5 mi (841 m) and 0.18 mi (295 m), respectively.

( printed page 28447)

Figure 1—Overview of IBR Project Location along I-5 between Portland, OR, and Vancouver, WA

Detailed Description of the Specified Activity

A detailed description of IBRP's planned activities are provided in the Proposed Rule. Since publication of the proposed rule, IBRP has not made any modifications to their activities; therefore, we direct the reader to the proposed rule for a detailed description. Similar to the proposed rule, mitigation, monitoring, and reporting measures proposed by IBRP, and included in this final rule are, described in detail later in this document (please see Mitigation and Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

Three species of marine mammals, comprising three stocks, may be taken by harassment incidental to IBRP's specified activities. A complete description of marine mammal status and trends, life history, habitat use, and threats is included in IBRP's application and NMFS' Proposed Rule. These details are not repeated here except for the reference table containing status, stock abundance, potential biological removal levels, and annual rates of mortality and serious injury (table 2). ( printed page 28448)

Potential Effects of Specified Activities on Marine Mammals and Their Habitat

The effects of underwater noise from the IBRP's construction activities have the potential to result in harassment of marine mammals in the Columbia River. We refer the reader to the Proposed Rule for a full discussion of the effects of anthropogenic noise on marine mammals in general and the potential effects of the specified activities on marine mammals and their habitat. There is no newly available relevant information that would change our analyses or the results thereof.

Estimated Take of Marine Mammals

Harassment is the only type of take expected to result from these activities. Except with respect to certain activities not pertinent here, section 3(18) of the MMPA defines “harassment” as any act of pursuit, torment, or annoyance which: (i) has the potential to injure a marine mammal or marine mammal stock in the wild (Level A harassment); or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering (Level B harassment).

Authorized takes would primarily be by Level B harassment, as use of the acoustic sources ( i.e., pile driving activities) have the potential to result in disruption of behavioral patterns for individual marine mammals. There is also some potential for auditory injury (AUD INJ) (Level A harassment) to result, primarily for phocids because predicted AUD INJ zones are larger than for otariids. The required mitigation and monitoring measures are expected to minimize the potential for take and, if take were to occur, the severity of the taking to the extent practicable. As described previously, no serious injury or mortality is anticipated or proposed to be authorized for this activity.

This final rule incorporates the harassment thresholds used in the proposed rule to estimate the manner and number of takes analyzed in this final rule and LOA. In summary, IBRP's proposed activity includes the use of continuous (vibratory pile driving and extraction) and impulsive (impact pile driving) sources, and therefore the RMS sound pressure level (SPL) thresholds of 120 and 160 dB re 1µPa are applicable. NMFS also applied the Updated Acoustic Technical Guidance (NMFS, 2024) to determine the potential for Level A harassment, as described in the proposed rule.

Since publication of the proposed rule, NMFS has revised our consideration of the proposed source values for vibratory pile driving to account for the discrepancy between measured and assumed values noted in footnote 4 of table 10 in the Proposed Rule. Specifically, we made the following modifications:

• Single-hammer vibratory driving proxy source levels have been revised from 175 dB RMS to 170 dB RMS. Sound pressure levels above 170 dB RMS have not been measured for 24- to 48-in piles at any location; however, 170 dB RMS at 10 m from the incident pile is characteristic of the average measured values across locations;
• Proxy sound levels (dB RMS) for simultaneous vibratory driving of two piles have been adjusted from 178 dB RMS to 173 dB RMS, following the methodology outlined in the Proposed Rule for additive sources; and
• Proxy sound levels (dB peak) for simultaneous impact driving of two 24-in piles and for two 48-in piles have been adjusted due to an error in the proposed rule. The peak values were not correctly adjusted; these are now 201 dB peak and 210 dB peak, respectively. The RMS and SEL_ss values shown in table 10 of Proposed Rule were correct and have not changed, and no changes were made to the resulting Level A or Level B harassment zone isopleths and associated estimates of exposures.

As a result, straight-line distances to Level B harassment thresholds for vibratory pile driving decreased, but the ensonified area did not change due to the river curvature and site geography limiting sound propagation. Table 3 contains updated distances to thresholds and corresponding areas for vibratory pile driving activities in both the Columbia River and North Portland Harbor sites. ( printed page 28449)

The Proposed Rule included a description of the methodology IBRP used to estimate exposures from the specified activities. Potential take, by Level A and Level B harassment, was quantified for all three species as a guild based on recent surveys done by ODFW and WDFW (15.2 in September through April; 6.7 in May through August), the likelihood of exposure during each construction activity, and the number of days estimated for each activity. The estimated exposures for each activity in a given year were then summed to estimate total annual exposures. None of the changes in this final rule resulted in changes to the proposed estimates of take by Level A or Level B harassment (table 4).

The percentages of take estimated by Level A harassment shown in the Proposed Pule (0 percent for vibratory pile installation and extraction; 5 percent for unattenuated impact piling; 10 percent for attenuated impact piling) were based on the activity duration in a typical day, the estimated Level A harassment isopleths, and the ability of pinnipeds to avoid the areas with highest sound exposure levels by swimming through other areas of the river or harbor. The maximum average travel speed of California sea lions in the Columbia River moving between the Bonneville Dam and the river mouth has been calculated at approximately 5.4 km per hour (hr) (Wright et al., 2010). For animals traveling at half of the maximum speed (2.7 km/hr) to traverse the entirety of the largest predicted Level A harassment zone (from 0.52 km downstream to 0.52 km upstream during concurrent impact driving) would take approximately 22 minutes, and approximately 1 hour for animals traveling at 1 km/hr. The largest Level ( printed page 28450) A harassment zone calculated for 10 continuous hours of vibratory driving is 0.35 km (total of 0.7 km diameter) and would take an estimated 16 or 42 minutes for an animal to transit at 2.7 km/hr or 1 km/hr, respectively. The widths of the Columbia River and North Portland Harbor at the project site are approximately 841 m and 295 m, respectively. Therefore, animals in the Columbia River could potentially avoid the Level A harassment area entirely by increasing their distance from the relevant sound source. Animals in the North Portland Harbor would not be able to avoid the Level A harassment zone during transit.

NMFS considers it unlikely that an individual animal would remain in the 1 km zone immediately adjacent to the project site for more than 2 hours as there are no known resting or foraging areas in this urban, industrialized portion of the river. However, given the lack of site-specific observational data, the conservative proportions of take by Level A harassment presented in table 15 of the Proposed Rule and repeated in table 4 of this rule remain appropriate. Table 5 shows the maximum annual amount of take authorized in the LOA by species and stock, and the percentages of each stock that could be affected.

Mitigation

The MMPA requires NMFS set forth in regulations the permissible methods of taking pursuant to the activity and other means of effecting the least practicable adverse impact on the species or stock and its habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of the species or stock for taking for certain subsistence uses (referred to in shorthand as mitigation). NMFS regulations require applicants for incidental take authorizations to include information about the availability and feasibility (economic and technological) of equipment, methods, and manner of conducting the activity or other means of effecting the least practicable adverse impact upon the affected species or stocks and their habitat (50 CFR 216.104(a)(11)).

In evaluating how mitigation may or may not be appropriate to effect the least practicable adverse impact on species or stocks and their habitat, as well as subsistence uses where applicable, NMFS considers two primary factors which are described below. For a full discussion of NMFS' implementation of the least practicable adverse impact standard, see 89 FR 31488, 31517 (April 24, 2024) as an example.

(1) The manner in which, and the degree to which, the successful implementation of the measure(s) is expected to reduce impacts to marine mammals, marine mammal species or stocks, and their habitat, as well as subsistence uses. This considers the nature of the potential adverse impact being mitigated ( e.g., likelihood, scope, range). It further considers the likelihood that the measure will be effective if implemented (probability of accomplishing the mitigating result if implemented as planned), the likelihood of effective implementation (probability of implementation as planned); and

(2) The practicability of the measures for applicant implementation, which may consider such things as cost and impact on operations.

This final rule incorporates all mitigation measures contained within the proposed rule without change. We refer the reader to the Proposed Rule on those measures and the expected benefit to marine mammals. In summary, the mitigation measures in this final rule include providing training of the protocols and operating procedures to all relevant personnel before the start of all pile driving, soft starts and bubble curtain use during impact driving, as well as standard shutdown zones to avoid physical interaction of marine mammals and construction equipment. IBRP would utilize NMFS-approved protected species observers (PSOs) during all activities that have the potential to result in take. As fully described in the Proposed Rule, NMFS has determined that the mitigation measures proposed by IBRP and contained within this final rule result in the least practicable adverse impact on marine mammals.

PSOs

The IBRP must employ PSOs and establish monitoring locations as described in a NMFS-approved Marine Mammal Monitoring and Mitigation Plan. For all pile driving activities, land-based PSOs must be stationed at the best vantage points practicable to monitor for marine mammals and implement mitigation procedures. A minimum of two locations must be used to monitor the harassment zones to the maximum extent possible based on positioning and daily visibility conditions. PSOs must be able to implement shutdown or delay procedures when applicable through communication with the equipment operator. Pre-start clearance monitoring must take place 30 minutes prior to initiation of pile driving activity ( i.e., pre-start clearance monitoring) through 30 minutes post-completion of pile driving activity during periods of visibility sufficient for the lead PSO to determine that the shutdown zones are clear of marine mammals. Pile driving may commence only if, following 30 minutes of observation, it is determined by the lead PSO that the shutdown zones are clear of marine mammals.

Shutdown Zones

For all pile driving activity, the IBRP must implement shutdown zones with radial distances shown in table 6. The IBRP, construction supervisors and crews, PSOs, and relevant IBRP staff must prevent direct physical interaction with marine mammals during construction activity. If a marine mammal comes within 10 m of such activity, operations must cease and vessels must reduce speed to the minimum level required to maintain steerage and safe working conditions, as necessary to prevent direct physical interaction. ( printed page 28451)

If a marine mammal is observed entering or within the shutdown zone, all pile driving activities at that location must be halted. If pile driving is halted or delayed due to the presence of a marine mammal, the activity may not commence or resume until either the animal has voluntarily left and has been visually confirmed beyond the shutdown zone or 15 minutes have passed without re-detection of the animal. In the event of a delay or shutdown of activity resulting from marine mammals in the shutdown zone, animal behavior must be monitored and documented. If work ceases for more than 30 minutes, the shutdown zones must be cleared again for 30 minutes prior to reinitiating pile driving.

Soft Start

The IBRP will use soft start techniques when impact pile driving. Soft start requires contractors to provide an initial set of three strikes at reduced energy, followed by a 30-second waiting period, then two subsequent reduced-energy strike sets. A soft start would be implemented at the start of each day's impact pile driving and at any time following cessation of impact pile driving for a period of 30 minutes or longer. Soft start procedures are used to provide additional protection to marine mammals by providing warning and/or giving marine mammals a chance to leave the area prior to the hammer operating at full capacity.

Noise Attenuation System

The IBRP will use a bubble curtain during impact pile driving in water depths greater than 0.67 m. The bubble curtain would be operated as necessary to achieve optimal performance. At a minimum, the bubble curtain will distribute air bubbles around 100 percent of the piling circumference for the full depth of the water column, the lowest bubble ring will be in contact with the substrate for the full circumference of the ring, and the weights attached to the bottom ring will ensure 100 percent substrate contact. No parts of the ring or other objects would prevent full substrate contact. In addition, air flow to the bubblers would be balanced around the circumference of the pile.

A hydroacoustic monitoring plan will be implemented during impact pile driving to confirm the attenuation device is installed and functioning as designed. This monitoring program will require some unattenuated pile strikes to confirm the amount of attenuation provided by the system. An estimated number of unattenuated pile strikes are also factored in to account for periods when the bubble curtain may not be providing sufficient attenuation. IBRP estimates that up to 75 unattenuated strikes may be required for a period of approximately 10 minutes approximately 1 day per week. Testing will occur for up to approximately 30 days during the 5-year period covered under this LOA, and on approximately 40 days total over the course of the in-water construction period.

Monitoring and Reporting

In order to issue take authorization for an activity, section 101(a)(5)(A) of the MMPA states that NMFS must set forth requirements pertaining to the monitoring and reporting of such taking. The MMPA implementing regulations at 50 CFR 216.104(a)(13) indicate that requests for authorizations must include the suggested means of accomplishing the necessary monitoring and reporting that will result in increased knowledge of the species and of the level of taking or impacts on populations of marine mammals that are expected to be present while conducting the activities. Effective reporting is critical both to compliance as well as ensuring that the most value is obtained from the required monitoring.

Monitoring and reporting requirements prescribed by NMFS should contribute to improved understanding of one or more of the following:

• Occurrence of marine mammal species or stocks in the area in which take is anticipated (e.g., presence, abundance, distribution, density);
• Nature, scope, or context of likely marine mammal exposure to potential stressors/impacts (individual or cumulative, acute or chronic), through better understanding of: (1) action or environment (e.g., source characterization, propagation, ambient noise); (2) affected species ( e.g., life history, dive patterns); (3) co-occurrence of marine mammal species with the activity; or (4) biological or behavioral context of exposure ( e.g., age, calving or feeding areas);
• Individual marine mammal responses (behavioral or physiological) to acoustic stressors (acute, chronic, or cumulative), other stressors, or cumulative impacts from multiple stressors;
• How anticipated responses to stressors impact either: (1) long-term fitness and survival of individual marine mammals; or (2) populations, species, or stocks;
• Effects on marine mammal habitat (e.g., marine mammal prey species, acoustic habitat, or other important ( printed page 28452) physical components of marine mammal habitat); and
• Mitigation and monitoring effectiveness.

IBRP will abide by all monitoring and reporting measures contained within this final rule and LOA, and a NMFS-approved Marine Mammal Monitoring and Mitigation Plan. This final rule incorporates all monitoring measures contained within the Proposed Rule, without change. We refer the reader to the Proposed Rule for details regarding those measures and provide a summary of those measures below.

In summary, IBRP will utilize PSOs at least 30 minutes prior to, during, and 30 minutes after all activities that may result in take of marine mammals. PSOs will be independent of the activity contractor ( e.g., employed by a subcontractor) and have no other assigned tasks during monitoring periods. At least one PSO must have prior experience performing the duties of a PSO during an activity pursuant to a NMFS-issued ITA or Letter of Concurrence. Other PSOs may substitute other relevant experience, education (degree in biological science or related field), or training for prior experience performing the duties of a PSO.

PSOs should also have the following additional qualifications:

(a) The ability to conduct field observations and collect data according to assigned protocols;

(b) Experience or training in the field identification of marine mammals, including the identification of behaviors;

(c) Sufficient training, orientation, or experience with the construction operation to provide for personal safety during observations;

(d) Sufficient writing skills to record required information including but not limited to the number and species of marine mammals observed; dates and times when in-water construction activities were conducted; dates, times, and reason for implementation of mitigation (or why mitigation was not implemented when required); and marine mammal behavior; and

(e) The ability to communicate orally, by radio or in person with project personnel to provide real-time information on marine mammals observed in the area as necessary.

IBRP will also conduct hydroacoustic monitoring of both attenuated and unattenuated impact pile installation. Although hydroacoustic monitoring of vibratory pile driving was inadvertently included in the proposed rule, no hydroacoustic monitoring of vibratory driving is planned and none is required. Acoustic monitoring must consist of multiple hydrophones deployed at 10 m and in the far field with a direct, unobstructed path between the sound source and the hydrophones. System design and calibration must be appropriate for the expected sound levels to be recorded, with a frequency response between 20 hertz (Hz) and 20 kilohertz (kHz). Environmental data must also be collected, as well as information on the substrate composition, hammer model and size, hammer energy settings, and any other relevant information. Further details of the acoustic monitoring are discussed in the Proposed Rule and are not repeated here.

The reporting measures contained with the Proposed Rule are included in this final rule with two minor changes. First, references to reporting requirements for hydroacoustic monitoring of vibratory pile driving have been removed from the regulatory text. Secondly, in the regulatory text of the Proposed Rule, § 217.146(d)(4) omitted standard language requiring the reporting of the number of marine mammals detected within the harassment zones, by species. This standard language has been included in § 217.146(d)(4)(ix) of the regulatory text and section 6(b)(x) of the associated LOA.

The reports must contain dates and times of all marine mammal monitoring and the construction activities occurring during each daily observation period, the total duration of driving time for each pile (vibratory driving), and number of strikes for each pile (impact driving); environmental conditions during monitoring periods (at beginning and end of PSO shift and whenever conditions change significantly). Upon observation of a marine mammal, PSOs must record the name of the PSO who sighted the animal, observer location, and construction activity at time of sighting; identification of the animal to the lowest possible taxonomic level, PSO confidence in identification, and the composition of the group if there is a mix of species; distances and bearings of each marine mammal observed in relation to the pile being driven for each sighting; estimated number of animals by species and age class; closest point of approach and estimated time spent within the harassment zone. PSOs must also provide a description of any marine mammal behavioral observations, including an assessment of behavioral responses to the activity, the number of marine mammals detected within the harassment zones, by species, and detailed information about any implementation of any mitigation, a description of specific actions that ensued, and resulting changes in the behavior of the animal, if any. All PSO data must be submitted in an electronic format that can be queried such as a spreadsheet or database ( i.e., digital images of data sheets are not sufficient).

IBRP will submit interim monthly reports as well as a draft annual report within 90 calendar days of completion of marine mammal monitoring each year and a draft 5-year comprehensive summary to NMFS 90 days after the expiration of the regulations. Revised annual and 5-year reports must be prepared and submitted to NMFS within 30 days following receipt of any NMFS comments on the draft reports. Details on how monitoring reports will be submitted to NMFS and the information required in each report are detailed in the proposed rule and included in the associated LOA.

Acoustic monitoring report(s) must be submitted on the same schedule as visual monitoring reports ( i.e., within 90 days following the completion of construction). The acoustic monitoring report must contain the informational elements described in the acoustic monitoring plan and, at minimum, must include:

• Hydrophone equipment and methods: (1) recording device, sampling rate, calibration details, distance (m) from the pile where recordings were made; and (2) the depth of water and recording device(s);
• Location, identifier, orientation (e.g., vertical, battered), material, and geometry (shape, diameter, thickness, length) of pile being driven, substrate type, method of driving during recordings ( e.g., hammer model and energy), and total pile driving duration;
• Whether a sound attenuation device is used and, if so, a detailed description of the device used, its distance from the pile and hydrophone, and the duration of its use per pile; and
• For impact pile driving: (1) number of strikes per day and per pile and strike rate; (2) depth of substrate to penetrate; (3) decidecade (one-third octave) band spectra in tabular and figure formats computed on a per-pulse basis, including the arithmetic mean or median for all computed spectra; (4) pulse duration and median, mean, maximum, minimum, and number of samples (where relevant) of the following sound level metrics: (5) RMS SPL; (6) 24-hour sound exposure level (SEL₂₄), peak (PK) SPL, and SEL_ss.

If no comments are received from NMFS within 30 days after the submission of the draft report, the draft report would constitute the final report. If the IBRP received comments from ( printed page 28453) NMFS, a final report addressing NMFS' comments would be submitted within 30 days after receipt of comments. The estimated harassment and shutdown zones may be modified with NMFS' approval following NMFS' acceptance of an acoustic monitoring report.

As described in the Proposed Rule, in the event that personnel involved in IBRP's activities discover an injured or dead marine mammal, IBRP would report the incident to the Office of Protected Resources, NMFS ( PR.ITP.MonitoringReports@noaa.gov), and to the West Coast Regional Stranding Coordinator as soon as feasible. If the death or injury was clearly caused by the specified activity, IBRP would be required to immediately cease the specified activities until NMFS is able to review the circumstances of the incident and determine what, if any, additional measures are appropriate to ensure compliance with this final rule. IBRP would not resume their activities until notified by NMFS. The report must include the time, date, and location (latitude/longitude) of the first discovery (and updated location information if known and applicable), the species identification (if known) or description of the animal(s) involved, the condition of the animal(s) (including carcass condition if the animal is dead), and the observed behaviors of the animal(s), if alive. Additionally, the report should include photographs or video footage of the animal(s), if available, and the general circumstances under which the animal was discovered.

Negligible Impact Analysis and Determination

NMFS has defined negligible impact as an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival (50 CFR 216.103). A negligible impact finding is based on the lack of likely adverse effects on annual rates of recruitment or survival ( i.e., population-level effects). An estimate of the number of takes alone is not enough information on which to base an impact determination. In addition to considering estimates of the number of marine mammals that might be “taken” through harassment, NMFS considers other factors, such as the likely nature of any impacts or responses ( e.g., intensity, duration), the context of any impacts or responses ( e.g., critical reproductive time or location, foraging impacts affecting energetics), as well as effects on habitat, and the likely effectiveness of the mitigation. We also assess the number, intensity, and context of estimated takes by evaluating this information relative to population status. Consistent with the 1989 preamble for NMFS' implementing regulations (54 FR 40338, September 29, 1989), the impacts from other past and ongoing anthropogenic activities are incorporated into this analysis via their impacts on the baseline ( e.g., as reflected in the regulatory status of the species, population size and growth rate where known, ongoing sources of human-caused mortality, or ambient noise levels).

As described in the Proposed Rule, there are several key factors to assess whether potential impacts associated with a specified activity should be considered negligible. These include (but are not limited to) the type and magnitude of taking, the amount and importance of the available habitat for the species or stock that is affected, the duration of the anticipated effect on the individuals, and the status of the species or stock.

As described in the Changes from Proposed to Final Rule section and Estimated Take section of this final rule, NMFS identified minor adjustments to the proxy source level assumptions and methodology that resulted in small decreases to the ensonified areas within the Level A harassment zones. However, there was no associated change to the proposed amount of take by Level A harassment for any species anticipated to occur incidental to the specified activities. Given these limited, minor adjustments, NMFS has determined that this new information does not change any of the preliminary analyses, conclusions, or determinations in the Proposed Rule. Therefore, the preliminary analyses, conclusions, and determinations included in the Proposed Rule for all three species and stocks remain the same for this final rule. A summary of the expected effects of the taking allowed for in this final rule, the primary factors considered, and those findings as provided in the Proposed Rule are described below.

In summary, exposures to elevated sound levels produced during IBRP's activities may cause behavioral disturbance of some individuals within the vicinity of the sound source and have the potential to cause a small amount of slight auditory injury. The amount of annual take authorized is less than 18 percent of all stocks. NMFS notes that behavioral responses ( e.g., increased swimming speeds, changing directions of travel and diving and surfacing behaviors, increased respiration rates, or decreased foraging (if such activity were occurring) of marine mammals to construction noises are expected to be mild, short term, and temporary. Marine mammals may not present any visual cues they are disturbed by activities, or they could become alert, avoid the area, leave the area, or have other mild responses that are not observable such as increased stress levels ( e.g., Rolland et al., 2012; Bejder et al., 2006; Rako et al., 2013; Pirotta et al., 2015; Pérez-Jorge et al., 2016). They may also exhibit increased vocalization rates ( e.g., Dahlheim, 1987; Dahlheim and Castellote, 2016), louder vocalizations ( e.g., Frankel and Gabriele, 2017; Fournet et al., 2018), alterations in the spectral features of vocalizations ( e.g., Castellote et al., 2012), or a cessation of communication signals ( e.g., Tsujii et al., 2018).

All three marine mammal species present in the region will only be present temporarily based on seasonal patterns or during transit between other habitats. Thus, individuals present will be exposed to only transient periods of noise-generating activity as they move up- or down-river past the project site. Most likely, individual animals will either be temporarily deterred from swimming past the construction activities and will pass by when no pile driving is occurring or will swim through the area more quickly. Takes may also occur during important foraging seasons, when anadromous fishes are migrating past the IBR Project and marine mammals follow. However, the IBR Project area represents a small portion of available foraging habitat and impacts on marine mammal feeding for all species are expected to be minimal. No marine mammal species or individuals are known or expected to be resident in the IBR Project area, and impacts are unlikely to be more than temporary and low-intensity.

The intensity of harassment events would be minimized through use of mitigation measures described herein, which were not quantitatively factored into the take estimates. As stated in the Mitigation section, the IBRP will implement shutdown zones (table 6). Take by Level A harassment will be authorized for all three marine mammal species to account for the potential that an animal could enter and remain unobserved within the estimated Level A harassment zone for a duration long enough to incur AUD INJ. Any take by Level A harassment is expected to arise from, at most, a small degree of AUD INJ because animals would need to be exposed to higher levels and/or longer duration than are expected to occur here in order to incur any more than a small degree of AUD INJ. ( printed page 28454)

In summary, the following factors primarily support our negligible impact determinations for the affected stocks of California sea lions, Steller sea lions, and harbor seals:

• No takes by mortality or serious injury are anticipated or authorized;
• Any acoustic impacts to marine mammal habitat from pile driving are expected to be temporary and minimal;
• Take will not occur in places and/or times where take would be more likely to accrue impacts on reproduction or survival, such as within habitats critical to recruitment or survival (e.g., rookery);
• The IBR Project area represents a very small portion of the available foraging area for all potentially impacted marine mammal species and does not contain any habitat of particular importance;
• Take will occur only within the Columbia River and North Portland Harbor, which is a limited, confined area of any given stock's home range;
• Monitoring reports from similar work have documented little to no observable effect on individuals of the same species impacted by the specified activities;
• The required mitigation measures (i.e., soft starts, pre-clearance monitoring, shutdown zones, bubble curtains) are expected to be effective in reducing the effects of the specified activity by minimizing the numbers of marine mammals exposed to injurious levels of sound and by ensuring that any take by Level A harassment is, at most, a small degree of AUD INJ and of a lower degree that would not impact the fitness of any animals; and
• The intensity of anticipated takes by Level B harassment is low for all stocks consisting of, at worst, temporary modifications in behavior, and would not be of a duration or intensity expected to result in impacts on reproduction or survival.

Based on the analysis contained herein of the likely effects of the specified activity on marine mammals and their habitat, and taking into consideration the implementation of the required monitoring and mitigation measures, NMFS finds that the total marine mammal take from the planned specified activity would have a negligible impact on all affected marine mammal species or stocks.

Small Numbers

As noted previously, only take of small numbers of marine mammals may be authorized under section 101(a)(5)(A) and (D) of the MMPA for specified activities other than military readiness activities. The MMPA does not define small numbers and so, in practice, where estimated numbers are available, NMFS compares the maximum number of individuals taken in any year to the most appropriate estimation of abundance of the relevant species or stock in our determination of whether an authorization is limited to small numbers of marine mammals. When the predicted maximum annual number of individuals to be taken is fewer than one-third of the species or stock abundance, the take is considered to be of small numbers (see 86 FR 5322, January 19, 2021). Additionally, other qualitative factors may be considered in the analysis, such as the temporal or spatial scale of the activities.

As in the proposed rule, the maximum annual amount of take allowed under the final rule is less than one-third of the population abundance estimates for all stocks (table 5). The numbers of animals authorized to be taken are small relative to the relevant species or stock abundances even if each estimated take occurred to a new individual, and even if all take accrued to a single stock.

Given there is no substantive change to the small numbers analysis described in the proposed rule, it is herein incorporated by reference. Based on the analysis contained herein of the proposed activity (including the proposed mitigation and monitoring measures) and the anticipated take of marine mammals, NMFS finds that small numbers of marine mammals would be taken relative to the population size of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

There are no relevant subsistence uses of the affected marine mammal stocks or species implicated by this action. Therefore, NMFS has determined that the total taking of affected species or stocks would not have an unmitigable adverse impact on the availability of such species or stocks for taking for subsistence purposes.

Adaptive Management

The regulations governing the take of marine mammals incidental to IBRP's proposed construction activities would contain an adaptive management component.

The reporting requirements associated with this final rule are designed to provide NMFS with monitoring data from the previous year to allow consideration of whether any changes are appropriate. The use of adaptive management allows NMFS to consider new information from different sources to determine (with input from IBRP regarding practicability) on an annual basis if mitigation or monitoring measures should be modified (including additions or deletions). Mitigation or monitoring measures could be modified if new data suggests that such modifications would have a reasonable likelihood more effectively achieving the goals of the mitigation and monitoring and if the measures are practicable.

The following are examples of the possible sources of applicable data to be considered through the adaptive management process: (1) results from monitoring reports, as required by MMPA authorizations; (2) results from general marine mammal and sound research; and (3) any information which reveals that marine mammals may have been taken in a manner, extent, or number not authorized by these regulations or subsequent LOA.

Endangered Species Act

Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq.) requires that each Federal agency ensure that any action it authorizes, funds, or carries out is not likely to jeopardize the continued existence of any endangered or threatened species or result in the destruction or adverse modification of designated critical habitat. To ensure ESA compliance with its issuance of ITAs, NMFS consults internally whenever we propose to authorize take for endangered or threatened species, in this case with the NMFS West Coast Regional Office.

No incidental take of ESA-listed species is proposed for authorization or expected to result from this activity. Therefore, NMFS has determined that formal consultation under section 7 of the ESA is not required for this action.

National Environmental Policy Act

To comply with the National Environmental Policy Act of 1969 (NEPA; 42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, NMFS must review our proposed action ( i.e., promulgation of regulations and subsequent issuance of an LOA thereunder) with respect to potential impacts on the human environment.

This action is consistent with categories of activities identified in Categorical Exclusion B4 (ITAs with no anticipated serious injury or mortality) of the Companion Manual for NAO 216-6A, which do not individually or cumulatively have the potential for significant impacts on the quality of the human environment and for which we have not identified any extraordinary ( printed page 28455) circumstances that would preclude this categorical exclusion. Accordingly, NMFS has determined that the issuance of the incidental take regulations and LOA qualifies to be categorically excluded from further NEPA review.

Promulgation

As a result of these determinations, NMFS is promulgating these regulations that: (1) allow for take of three marine mammal species, comprising three stocks, by Level A and Level B harassment, incidental to construction activities associated with the IBR Project for a 5-year period from September 15, 2027, through September 14, 2032; and (2) prescribe mitigation, monitoring and reporting measures.

Classification

Executive Order 12866

The Office of Management and Budget determined that this final rule is not significant for purposes of Executive Order (E.O.) 12866.

Executive Order 14192

This final rule is not an E.O. 14192 regulatory action because this action is not significant under E.O. 12866.

Regulatory Flexibility Act (RFA)

Pursuant to section 605(b) of the Regulatory Flexibility Act (5 U.S.C. 601 et seq.), the Chief Counsel for Regulation of the Department of Commerce has certified to the Chief Counsel for Advocacy of the Small Business Administration during the proposed rule stage that this action would not have a significant economic impact on a substantial number of small entities. The IBRP is a bi-state governmental program focused on improving the transit corridor between Washington and Oregon. The IBRP is the sole entity that would be subject to the requirements of this final rule, and the IBRP is not a small governmental jurisdiction, small organization, or small business, as defined by the RFA, because it is a department of the two state governments. Because of this certification, a final regulatory flexibility analysis is not required and none has been prepared.

Paperwork Reduction Act (PRA)

This final rule contains a collection-of-information requirement subject to the provisions of the PRA. Notwithstanding any other provision of law, no person is required to respond to nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the PRA unless that collection of information displays a currently valid OMB control number. These requirements have been approved by OMB under control number 0648-0151 and include applications for regulations, subsequent LOAs, and reports.

For the reasons set forth in the preamble, NMFS amends 50 CFR part 217 as follows:

91 FR 28443