By Tessa Danelesko
It is no surprise that many ocean goers dream of hearing the huff produced by a surfacing leatherback sea turtle. A sighting of these visitors to the British Columbian coast is often considered a rare treat. That dream may soon become an impossible reality however, as the critically endangered species faces increasing pressure from human threats. A new study has indicated that leatherback sea turtles are facing almost certain extinction, an event that could happen in as few as 20 years. This finding not only reveals how dire the current situation is for leatherbacks in the Pacific Ocean, but how urgent changes need to be made to prevent this species from disappearing from our coast forever.
Little is known about these ocean giants, but many hypotheses indicate leatherbacks venture to our backyard, the eastern Pacific, in search of their prey: jellies. It is thought they follow the California Current Large Marine Ecosystem (CCLME) and the North Pacific transition zone marine ecosystem from Southeast Asia to jelly rich water, an area that extends from Mexico up to our B.C. coast.
You may be wondering, if food is so plentiful here, why do these turtles leave? Leatherbacks migrate over 4800 kilometers from our shores, across the Pacific, to nest. Nesting beaches can be found in Sri Lanka, Malaysia, Papua New Guinea, and Indonesia. Since the 1980s, many of these beaches have experienced a massive decline in the number of leatherback sea turtle nests. Most alarmingly, beaches along the north coast of Indonesia’s Bird’s Head Peninsula have shown an annual decline of 5.9% in the number of observed leatherback nests. This region, the area studied in the research mentioned above, is thought to account for 75% of the total leatherback nesting in the western Pacific.
The new study, conducted by an international team of scientists and led by the University of Alabama at Birmingham (UAB), was published in Ecosphere last month. Researchers surveyed two Indonesian beaches, Jamursaba Medi and Wermon, for leatherback sea turtle nests from 2005-2011. The team compared numbers from these recent surveys, the most extensive study done on leatherbacks to date, to previous nest counts. The comparison revealed the number of nests in this crucial area has declined by a total of 78% since the mid 1980s. Authors of the study estimate that if this trend continues, within 20 years it would be almost impossible for leatherbacks to avoid extinction.
Support sea turtles
While the number of nests at the last remaining stronghold for leatherbacks in the Pacific has declined, mature adults far from the beach are also facing increasing threats. Bycatch, the accidental capture of sea turtles in fishing gear, is estimated to cause a more than 5% population decline annually. Ocean-front development and egg poaching are also reducing the already small number of hatchlings that successful reach maturity.
In this 11th hour, there are ways to make a difference. Even from shore, taking action to support sustainable fisheries can promote sea turtle conservation, as those fisheries aim to minimize bycatch, including that of sea turtles. The Vancouver Aquarium’s OceanWise program can help you make those important ocean-friendly choices. Additionally, help prevent marine debris from affecting sea turtles, by participating in the annual Great Canadian Shoreline Clean-up.
If you are lucky enough to be at sea though, keep in mind that while rare off our coast, leatherback sightings are possible. You can directly participate in sea turtle conservation by taking a photo and immediately reporting any sightings of sea turtles and cetaceans to the Vancouver Aquarium’s B.C. Cetacean Sightings Network at 1-866-I-SAW-ONE or online here.