Another satellite study shows that leatherbacks are at risk in the Atlantic Ocean, too.
The report of the research follows identification of two trouble spots in the Pacific.
The latest study comes from the University of Exeter. The last large populations of the leatherback turtle are at risk because their migratory routes in the Atlantic Ocean clash with the locations of industrial fisheries, a new study said.
Researchers used data from satellite transmitters attached to the turtles to track their movements across the Atlantic Ocean. These movements were then overlapped with information on high pressure fishing areas to identify where the turtles are most susceptible to becoming entangled and where they may drown.
The international study, jointly led by Matthew Witt of the University of Exeter and Sabrina Fossette of Swansea University, found that urgent international efforts are needed to protect the species.
Between 1995 and 2010, a total of 106 leatherback turtles were satellite-tracked in the Atlantic and south-west Indian Oceans. Resulting information was interpreted along with knowledge on longline fishing effort and nine areas with the highest risk of bycatch were identified.
Maps of the turtles’ daily locations revealed that Atlantic leatherbacks use both deep sea international waters more than 200 nautical miles from land and coastal national waters, either seasonally or year-round, in a complex pattern of habitat use.
More than four billion hooks were set throughout the entire Atlantic Ocean by industrial fisheries between 1995 and 2010, equivalent to 730,000 hooks per day, the researchers estimated.
The study, published last week in Proceedings of the Royal Society B, shows that of the nine areas of high susceptibility for leatherbacks, four are in the North Atlantic and five in the South and Equatorial Atlantic.
In the earlier study, reported last week, a team of researchers said they tracked by satellite 135 leatherback turtles to determine that there are two spots in the Pacific where the creatures are in the greatest danger from longline fishing.
For a population of the giant turtles that nests in Costa Rica and Mexico the greatest danger is in a broad area off Perú known as the South Pacific Gyr, according to a report from Cornell University.
This group migrates along a corridor past the Galapagos Islands.
The gyr is an area where the ocean moves in a broad circle due to currents and winds.
One of the researchers is Stephen Morreale, a Cornell research associate. Also involved is James R. Spotila of Drexel University, who is known to Costa Ricans as the president of the Leatherback Trust.