Large female leatherback turtle
at a nesting beach in the Solomon Islands, December 2006.Carapace length is 1.84m.
Scott Benson is seated. Photo:
Karin A. Forney.
international team of scientists from NOAA Fisheries Service and several
western Pacific research and conservation organizations published a paper today
in the journal Ecosphere that reveals
how leatherback turtles use vast areas of the Pacific Ocean and Indo-Pacific
seas. The study, based on data from 126 leatherbacks tracked by satellite, is
part of continuing research to understand how oceanographic features influence
migration and foraging behavior of leatherbacks in order to improve
conservation efforts for this endangered species.
Leatherbacks (Dermochelys coriacea) are the largest of
all marine turtles weighing up to 2000 pounds (900 kg) and almost six feet (2
m) in length. Extensive harvesting of
eggs and breeding females by indigenous populations on the nesting beaches
along with accidental capture in fisheries has led to the demise of leatherback
populations around the Pacific. Some of the last remaining Pacific nesting
populations are found in the western Pacific in Indonesia,
Solomon Islands and Papua New Guinea.
lay their eggs on tropical nesting beaches, but then migrate to foraging areas
around the world to feed on jellyfish. Leatherbacks are seasonal visitors to
the central California
coast, arriving in late summer and fall to forage on large aggregations of
brown sea nettles (Chrysaora fuscescens).
Scott Benson, lead
author of the paper, and senior author Peter Dutton began tracking leatherbacks
from the California foraging grounds in 2000
and expanded the study to the nesting beaches in the western Pacific after
documenting that the California
turtles were from there. Benson said
“We discovered a much greater diversity of foraging behavior than previously
thought for Pacific leatherbacks.” The western Pacific nesters foraged not only
in distant temperate ecosystems of the North Pacific, but also in temperate and
tropical Large Marine Ecosystems (LME’s) of the southern hemisphere and
Indo-Pacific seas. Benson said “The foraging areas we identified exhibited a
wide range of oceanographic features, including mesoscale eddies, coastal retention
areas, current boundaries, or stationary fronts, all of which are known
mechanisms for aggregating leatherback prey.
The NOAA Fisheries
Service has restricted commercial fishing in large areas north of Hawaii and off the United States
west coast because of concern over accidental bycatch of leatherbacks, and has
proposed designating some areas as critical habitat, said Tomoharu Eguchi, a
co-author of the paper. The paper also
identifies foraging areas in the East Australia Current Extension and the
Tasman Front drawing attention to the potential threat from the intense fishing
by international fleets in these waters.
Ricardo Tapilatu of
the State University of Papua (UNIPA) said “The turtles nesting at Papua Barat
(Indonesia), Papua New Guinea,
and other islands in our region depend on food resources in waters managed by
many other nations for their survival.
It is important to protect leatherbacks in these foraging areas so that
our nesting beach conservation efforts can be effective.” Creusa Hitipeuw of World Wildlife Fund for
Nature – Indonesia added, “These findings are very useful for the Coral
Triangle Initiative in the Western Pacific as one of the goals is to develop
and implement a regional action plan to protect leatherback turtles and their
The combined results
have fundamentally changed the scope of conservation efforts for Pacific
leatherbacks. “Tracking the turtles on their extraordinary migrations over the years
has allowed us to finally piece together the complex linkages between their
breeding areas and feeding areas”, said Dutton.
“The leatherbacks have acted as international ambassadors and led us to
join with many nations and communities on both sides of the Pacific in a
concerted effort to conserve this endangered species”.
Read the NOAA Press Release
Read the paper here (scroll down to #art84)
more about Southwest Fisheries Science Center Marine Turtle Research