PIFSC Sea Turtle Longline Research EA June 1, 2009
The following actions are included in the current program evaluated in this PEA:
PIFSC research using contracted vessels in the Hawaii-based longline fishery: A number of vessels in the Hawaii-based longline fleet have been contracted (not chartered) to test modified longline gear under statistically-controlled conditions. To date, the controlled studies conducted on the contracted boats have involved the use of alternate gear and bait colors, alternate fishing depths and times, and specific types and sizes of circle hooks (Boggs 2004). Initial experiments in 2002 employed five vessels in several experiments to:
Determine if modified fishing methods would remain commercially economically viable.
Measure the time and duration of turtles being hooked on the line prior to being brought to the surface (using hook timers) to better understand and avoid the times of day when sea turtles are most vulnerable to hooking,
Results indicated that stealth gear using blue-colored gear and bait and low-spectrum yellow lightstick lures, deep fishing for swordfish during the day when they swim deep rather than at night when they swim shallow, and circle hooks significantly reduced swordfish catch rates in these experiments (Boggs 2004). No conclusions were reached (or expected) regarding turtle hooking rates from the few turtles caught. These experiments were authorized under an ESA Section 10 Permit for Scientific Research (#1303), which was subsequently withdrawn as a result of litigation. Other research indicated that blue-colored gear and bait was not sufficient camouflage for sea turtles (Swimmer et al. 2005).
Alternating circle and traditional tuna hooks (e.g., tuna or J hooks) on foreign vessels, with observers on board to determine differences in catch rates of target species: Current experiments involve furnishing foreign vessels with large circle hooks (18/0) alternated with traditional tuna hooks throughout each set to test catch rates of these hooks for target fish species when used during normal tuna longline fishing operations. Participating countries include Italy, Spain (coastal fishery), Ecuador, Peru, Brazil, Mexico (Gulf fishery), Costa Rica, Uruguay, and Guatemala. Some technical consulting has been exchanged with Japanese scientists conducting longline fishery testing of circle hooks using research vessels, mostly using methods like those used in the shallow-set fishery for swordfish and shark in the North West Pacific, but also using deep-set tuna fishery methods in the equatorial Pacific.
NMFS collaboration with the World Wildlife Fund (WWF) and other organizations involved in international turtle conservation efforts: This program involves providing hooks and dehooking devices for use in several Central American and Asian fisheries, including Indonesia, Papua New Guinea (PNG), Viet Nam, and the Philippines.
NMFS, Western Pacific Fishery Management Council, Inter-American Tropical Tuna Commission (IATTC) and the World Wildlife Fund (WWF) Cooperative Studies in Ecuador: NMFS, along with Western Pacific Fishery Management Council, Inter-American Tropical Tuna Commission (IATTC) and the WWF, is actively involved in testing modified hooks (such as relatively large circle hooks) and bait types (such as comparing fish and squid bait) throughout Central America. Preliminary results documented by Largacha et al. (2005) for the first year of the effort from March 2004 through March 2005 found dramatically reduced leatherback and