WHAT CAN BE DONE TO RESTORE PACIFIC TURTLE POPULATIONS?
The Bellagio Blueprint for Action on Pacific Sea Turtles
6 January 2004

Reduce Turtle Take in At-Sea and Coastal Fisheries

The Bellagio Blueprint recognizes that all forms of mortality for Pacific sea turtles will need to be drastically reduced, not just egg mortality on nesting beaches. Turtles suffer significant but poorly quantified mortality from coastal and at-sea fisheries. Pacific sea turtles are migratory, weaving their way across the Pacific Ocean, in and out of Exclusive Economic Zones and the high seas. Breeding habitat can lie in one nation and their developing and foraging habitat may be in another nation’s waters or in the high seas where there is no inherent governance. In their journey, turtles must run a gauntlet of fishing fleets on both the high seas and coastal waters. Sea turtles interact with pelagic longline gear on the high seas, and beach seine, gillnet and shrimp trawl gears in coastal waters. These interactions can lead to death, most frequently through drowning, when the turtles cannot climb to the surface of the ocean to breathe after becoming hooked or entangled in the fishing gear. New types of gear or ways of fishing can significantly reduce the rate of interactions between turtles and gear or the mortality rate after an interaction has already occurred.

(i) Fishing mortality can be reduced by new technologies, as demonstrated by the use of turtle excluder devices (TEDS) on trawl nets and circle hooks and bait on long lines

Technology standards, when combined with reductions in turtle mortality from other sources, such as through nesting site protection, can contribute to the recovery of sea turtle populations. In contrast to many types of regulations, technology standards are comparatively easy to achieve compliance through monitoring and verification, since only a relatively quick inspection is required. New technologies to reduce sea turtle takes from fishing also permit the creativity of fishers to have full play. When consistently applied, they also have the potential to restructure the incentives for nations in such a way that both compliance and participation in this conservation initiative increase. The potential for increased participation (and hence reduction in free riding) in the conservation initiative, along with increased compliance, could even lead to reductions in sea turtle mortality that outweigh other conservation approaches that on paper may appear to be more effective, but in practice are not, due to problems of compliance, participation, and free riding on others’ conservation efforts. Adoption of these technology standards does not preclude adoption of other conservation initiatives, and in addition, research and extension programs can continue to refine and implement these technology standards.

• In coastal shrimp fisheries, turtle excluder devices or “TEDS” are a grid and trapdoor installed inside a trawling net that, while allowing shrimp to pass to the back of the net, direct sea turtles out and thereby reduce sea turtle bycatch by up to 97 percent.
• In pelagic longline fisheries, exciting new developments in gear and fishing methods in the Atlantic Ocean entailing 18/0 circle hooks and mackerel bait have been found to significantly reduce both the loggerhead and leatherback interactions when compared to the industry standard J hooks and squid bait. In addition, circle hooks significantly reduced the rate of hook ingestion by the loggerheads, thereby reducing the post-hooking mortality associated with interactions. The combination of 18/0 circle hooks and mackerel bait was found to be the most effective mitigation measure for both loggerhead and leatherback sea turtles. Mackerel bait was ascertained to be more efficient for swordfish than squid bait and circle hooks were more efficient for tuna than J hooks. In addition, after hooking by pelagic line gear, line cutters can reduce turtle mortality by allowing the turtle to swim away rather than bring the turtle on board the vessel and increasing the chance of mortality or injury.

(ii) Better understanding of the links between sea turtles and fisheries:

Better understanding of the links between sea turtles and fisheries allows the design of conservation initiatives that reduce their interactions and thereby sea turtle mortality. Better understanding of these links leads, in part, to designing fishing gear, and adopting management practices and methods of fishing that reduce the takes and mortality of sea turtles.

• Longline set depths can be critical to incidental sea turtle mortality. The depth at which longline gear are set and the length of leaders for individual hook lines from the main line affect both the takes and mortality of sea turtles. Shallower sets of longline gear are more likely to result in interactions between the turtles and the gear, since turtles are more likely to swim higher in the water column. Longer leaders can reduce sea turtle mortality once a turtle has been hooked or entangled in a leader, since the turtle can reach the surface to breathe.
• Wongara Beach Marine Park (Australia) fisheries closures at the times that coincide with loggerhead nesting are found to be effective. By better understanding the months and locations of loggerhead nesting sites in eastern Australia, Australia was able to establish seasonal fisheries closures for the Wongara Beach Marine Park. This prohibition of fishing in the nesting season and waters off nesting beaches prevented takes and subsequent fisheries-related mortality of loggerhead sea turtles.
• Sea turtle protection from coastal fisheries could be much more effective if the current major knowledge gaps regarding turtle take by coastal fishing gear were addressed. Little is known about the extent of sea turtle takes by coastal fishing gear, especially in the waters of developing nations, where most of the sea turtle nesting sites are located. The magnitude and severity of the sea turtle mortality is unknown, although it is believed to be a major factor. Without better knowledge and understanding of the turtle takes by coastal fishing gear, fully effective sea turtle conservation initiatives are difficult to design.

(iii) Promote a broad set of sea turtle conservation initiatives to mitigate all sources of fisheries-related turtle mortality

• USA Pacific coast fishermen have adopted a beach to protect nesting sites. Pelagic longline fishermen, working with the conservation group ASUPMATOMA (Asociacion Sudcaliforniana de Proteccion al Medio Ambiente y la Tortuga Marina), are in the process of adopting a nesting beach for leatherback sea turtles in Baja California, Mexico. Fishermen are providing funding to allow the conservation group, working in conjunction with Mexican authorities and local communities, to secure the eggs and nesting female leatherbacks from poachers and animal predators and to protect and improve nesting habitat, thereby increasing the success and survivor rate of egg laying and hatchings.