PIFSC Sea Turtle Longline Research EA June 1, 2009
decreased on domestic and foreign vessels because of the availability of releasing equipment and the presence of trained research personnel to use it.
Potential direct and cumulative impacts on endangered humpback whale populations in the Pacific Ocean
While humpback whales are not typically at risk from drowning or immediate death from longline gear, they are at increased risk of starvation, infection, physical trauma, and ship strikes. Reports of entangled humpback whales found swimming, floating or stranded with fishing gear (not limited to longline gear) attached have increased in recent years in both Alaskan and Hawaiian waters. For example, reports of entanglement from Hawaii totaled 23 from 2001 through 2006; however, 16 of those were from 2005 and 2006. Many of the whales reported entangled in Hawaii waters most likely brought gear with them from higher latitude feeding grounds. Interactions between the Hawaii-based longline fisheries and humpback whales are rare and unpredictable, with only 5 observed interactions since 2001, 2 of which were with the shallow-set component. Available evidence from entangled northern right whales in the north Atlantic Ocean indicate that large whales may be able to extricate themselves, especially if the gear is not wrapped around their bodies (NMFS 2008a).
The effects of fishing gear interactions on adult humpback whales are not likely to be different between deep-set and shallow-set gear because the animals are large enough to pull themselves to the surface. NMFS determined that the proposed number of sets for the Hawaii-based longline fishery that has the potential to kill one humpback every one to two years would not result in a reduction in the numbers, distribution, or reproduction of the North Pacific population of humpback whales (NMFS 2008a). It is likely that this would also be the case for humpback whale populations elsewhere in the world.
NMFS-implemented regulations that prohibit approach to humpback whales within 100 yards when on the water and 1,000 feet in the air (50 CFR 224.103). The regulations also make it unlawful to disrupt the normal behavior or prior activity of the whales, including interruptions to feeding, nursing, or resting behaviors. National security and the ability of the Navy to conduct realistic training using SONAR was recently decided by the Supreme Court to override the potential for adverse impacts to marine mammals from the use of SONAR in the central and eastern Pacific ocean, which could set a precedent for other areas.
Conclusion regarding potential impacts on cetacean populations from interaction with research-related longline fishing gear
In summary, takes of most species of marine mammals are very rare in longline fishing (SWFSC 2007). Therefore, the existing and proposed actions would have no effect on the listed species of marine mammals or species protected by the MMPA. Other than the regulations regarding approach to humpback whales, NMFS has no control over the other potential sources of cumulative impacts to humpback whales.