Endangered and Threatened Wildlife; Recovery Plans for Listed Marine Mammals

Background

Congress passed the Endangered Species Act in 1973 (16 U.S.C. 1531 et seq) (ESA) to protect species of plants and animals endangered or threatened with extinction. NMFS and the U.S. Fish and Wildlife Service share responsibility for the administration of the Act. NMFS is responsible for most marine mammal species, including the blue whale. Listed endangered and threatened species under NMFS jurisdiction are identified in 50 CFR 222.23(a) and 50 CFR 227.4, respectively. The List of Endangered and Threatened Wildlife, which contains species under the jurisdiction of both agencies, is provided in 50 CFR 17.11(h). The blue whale is listed as endangered. Section 4(f)(1) of the ESA requires that NMFS and FWS develop and implement recovery plans for the conservation and survival of endangered and threatened species, unless such plans would not promote the conservation of the species. A plan was prepared at the request of the Assistant Administrator for Fisheries to promote the recovery of blue whales. NMFS published a notice of availability of the draft recovery plan for blue whales in the Federal Register on August 1, 1997 (62 FR 41367). Comments were received from four people during the 60-day comment period. Reviewers' comments and NMFS' responses to the comments are identified here. Comment 1. The plan should place more emphasis than it currently does on blue whale stocks in the North Atlantic Ocean. Response. Changes have been made in various parts of the plan to reflect this comment. However, as noted in the plan, in the North Pacific Ocean, blue whale distribution in the North Atlantic Ocean is largely outside U.S. waters. Therefore, much of the emphasis on the North Pacific Ocean stocks remains. Comment 2. With regard to human interactions with blue whales, vessel strikes in particular, one commenter reported that 25 percent of the 355 blue whales photo-identified in the St. Lawrence River had scars attributable to vessel contact. Response. This observation has been added to the discussion of vessel disturbance in the Human Impact section. Comment 3. One comment indicated that toxic contaminants, particularly for ``blue whales found in the Gulf of St. Lawrence, carry significant levels of PCBs and pesticides such as DDT.'' Response. The discussion of contaminants in the Human Impact section was modified accordingly. Comment 4. One reviewer provided specific information on blue whale seasonal occurrence and distribution in the Gulf of St. Lawrence. Response. The discussion in the section on distribution and habitat use was expanded to include this information. Comment 5. A reviewer noted that, while likely true that Northern Hemisphere blue whales are generally smaller than their Southern Hemisphere counterparts, a 92-ft (28-m) female was reported in Davis Strait catch records, larger than the 27-m (89 ft) whale reported in the draft plan. Response. This change has been made and appears in the section on Species Description and Taxonomy. Comment 6. One commenter pointed out that, inasmuch as fin whales are sympatric with blue whales in a number of locations in the North Atlantic, they should be considered significant competitors for prey consumed by blue whales. Response. This comment is addressed in the section on Competition with the statement that ``[a]ll baleen whale species that are sympatric with the blue whale eat euphausiids to some extent and are, therefore, potential competitors.'' Comment 7. One commenter noted that the number of calves seen in the Gulf of St. Lawrence is low; only nine calves have been reported there in 19 years of research. Off Iceland, however, three calves were observed in only 10 days of surveys in July 1996 and July 1997. Also, several observations were provided on the sex ratio of calves and the timing of weaning. Response. These observations were incorporated into the discussion of reproduction. Comment 8. One commenter noted that 352 blue whales have been photo-identified in eastern Canadian and New England waters, and 32 have been identified from waters off Iceland. Response. These data have been added to the Abundance and Trends section. Comment 9. Two reviewers indicated that the research recommended in the plan was focused on surveys which tended to document ``effects'' rather than ``causes.'' They suggested that the plan identify studies designed to examine testable hypotheses, e.g., why are only the Icelandic and California populations apparently recovering? They suggested that one could, for example, test the hypothesis that populations with slow (or no) recovery rates feed on pelagic aggregations which tend to be less dense and more patchy than the euphausiid aggregations on which the coastally feeding blue whale populations (Iceland and California) feed. Response. This suggestion has been included in section 3.3 of the step-down outline narrative. Comment 10. More studies need to be done on the effects of anthropogenic underwater sound, including those originating from military operations. Response. NMFS believes that this is a valid comment and shares the view that anthropogenic underwater sound may adversely affect whales and their habitat. While NMFS believes that studies are needed to better understand these affects, it believes that this is a ``second tier'' threat relative to more direct threats. Also, it believes that possible adverse affects from underwater noise is systemic to nearly all oceanic waters and not a problem specific to blue whales and the recovery of blue whales. Therefore, studies specific to the affects of noise on blue whales were not identified in the plan. Nonetheless, the discussion of the status of research on the effects of sound emission from the Acoustic

Thermometry of Ocean Climate experiment and from the U.S. Navy's Low- Frequency Active sonar system testing is provided in the Habitat Degradation and Military Operations sections, respectively. Comment 11. With regard to the discussion on stocks in the North Pacific population, one commenter suggested adding the phrase `` ...based on the presence of rare epizoites on blue whales which were not found on other species known to migrate north ...'' to the sentence, ``[h]owever, he recently concluded that the California population is separate from that in the Gulf of and eastern Aleutians (Rice 1992).'' Response. This suggested change has been made. Comment 12. One reviewer challenged the assertion that blue whales regularly feed on the pelagic red crab, Pleuroncodes planipes, as reported by Rice (1974) and Rice (1986). Response. In response to this comment, the sentence that read ``[o]ne exception to their near-total dependence on euphausiid prey is that blue whales regularly feed on pelagic red crabs, Pleuroncodes planipes, off Baja California (Rice 1974, 1986)'' in the draft has been changed in the final plan to read, ``[o]ne exception to their near- total dependence on euphausiid prey is that blue whales have been observed feeding on pelagic red crabs, Pleuroncodes planipes, off Baja California (Rice 1974, 1986), although these observations have not been confirmed by subsequent observations or other analyses (e.g., fecal analysis).'' Comment 13. A reviewer suggested a change in the discussion about blue whale prey in the Gulf of California, Mexico. Response. Two sentences on this subject have been changed to read, ``[b]etween February and April, blue whales in the Gulf of California, Mexico, have been observed feeding on euphausiid surface swarms (Sears 1990), consisting mainly of Nyctiphanes simplex engaged in reproductive activities (Gendron 1990, 1992). Sears (1990) regarded Nyctiphanes simplex as the principal prey of blue whales in the region, and results from recent fecal analyses confirmed this assertion (Del Angel- Rodriguez and Gendron 1997).'' Comment 14. One reviewer indicated that the section on Reproduction did not, but should, indicate that the Gulf of California is the only known nursing and probable calving ground in the North Pacific. Response. The following sentence has been added ``[t]herefore, this area is likely an important nursing and calving area for the species.'' Comment 15. A reviewer pointed out that there are no regulations or guidelines for whale watching in Mexican waters and suggested that this be noted in the plan. Response. The boat disturbance discussion in the North Pacific section has been modified to reflect this comment. Comment 16. One reviewer noted that there are three (not two) blue whale photo-identification catalogs, including one for the waters off Baja California and portions of the Mexico mainland Pacific coast. Response. Under Narrative, section 2.3 of the Plan has been modified accordingly. Comment 17. A reviewer suggested that the importance of blue whale habitat in the Gulf of California be clarified in section 3.2 of the Narrative. Response. In response to this comment, the sentence on Mexico has been modified to read, ``[i]n Mexico, the waters of Baja California, particularly the southwestern portion of the Gulf of California where nursing, feeding, and probably calving occurs, are clearly of great importance to many eastern North Pacific blue whales, including whales that spend part of the year in U.S. waters.''

Authority: 16 U.S.C. 1531-1543 et seq.

Dated: October 19, 1998. Hilda Diaz-Soltero, Director, Office of Protected Resources, National Marine Fisheries Service. [FR Doc. 98-28508 Filed 10-22-98; 8:45 am] BILLING CODE 3510-22-F