Development of TurtleWatch for Leatherback Turtles is Underway

PIFSC scientists are partnering with colleagues at the NMFS Southwest Fisheries Science Center (SWFSC) and the University of Maryland to expand the NOAA TurtleWatch program with the objective of helping to reduce incidental fishery interactions with endangered leatherback sea turtles.

Loggerhead
Loggerhead

In 2006, the TurtleWatch tool was developed for endangered loggerhead turtles in the central North Pacific by Evan Howell of the PIFSC Ecosystem and Oceanography Division (EOD). Posted on the PIFSC website at www.pifsc.noaa.gov, the TurtleWatch advisory provides Hawaii-based pelagic longline fishermen with up-to-date information on the spatial pattern of sea surface temperature and surface currents in the Pacific Ocean north of the Hawaiian Islands and delineates the area of habitat preferred by loggerheads. Aided by this information, fishermen can decide on where to fish in ways that avoid the preferred habitat and reduce the chances of unwanted interactions with the turtles.

Leatherback
Leatherback

The new research project hopes to provide similar benefits with respect to leatherbacks. An analysis of recent data collected by federal observers placed on Hawaii-based longline fishing vessels shows that the shallow-set Hawaii-based longline fishery, which targets swordfish, has moved into waters significantly farther to the east than usual during the October-March main swordfish fishing season and has increased fishing effort in October-December. Data provided by the SWFSC on the habitat used by leatherback turtles, derived from satellite-tracked leatherbacks, show that the eastward movement of the shallow-set fishery is likely to bring the longline fleet into a migratory pathway of the turtles. When the tracking data are combined with remotely-sensed data on sea surface temperature, it appears that as leatherbacks move through the central North Pacific, they occupy 1 or 2 fairly well-defined migration corridors with defined surface temperature signatures. EOD scientists and their research partners are working with this information to produce a recommendation on leatherback avoidance zones, based on spatial and/or environmental criteria. Avoidance of the zones by longline fishers would reduce the likelihood of unwanted interactions with leatherback turtles. The researcher team hopes that the leatherback avoidance zones can be incorporated into the PIFSC TurtleWatch product.