On my daily beach walk I came across this dead animal (about 1 week ago, on the Lion Head beach close to the entrance to Hog Creek, in Springs, East Hampton):
Based on the pictures I took, it’s now been identified as Kemp’s Ridley Turtle. This is a critically endangered species. In fact it is the most endangered sea turtle species!
Obviously we would all like to know why this rare animal showed up on our beach, and what might have caused its death.
Adult turtles which reach sexual maturity at the age of 7-15 years, measure about 27″ in length. This specimen measured about approx. 15″ and was therefore a juvenile.
Kemp’s Ridley can be found along the Atlantic coast as far north as New Jersey. Mature adults migrate back to their nesting beach in Mexico every year: female Kemp’s Ridley turtles come together all at once in what is known as an arribada, which means “arrival” in Spanish. Nearly 95 percent of Kemp’s Ridley nesting worldwide occurs in Tamaulipas, Mexico. Nesting is usually between May and July, and females will lay up to three clutches of 100 eggs that must incubate for 50-60 days.
Hatchlings spend up to 10 years in the open ocean as juveniles. Kemp’s Ridley turtles occupy “neritic” zones, which contain muddy or sandy bottoms where their preferred prey is plentiful. Even in the ocean, the Kemp’s Ridley turtles rarely swim in waters deeper than about 160 feet.
Kemp’s Ridley turtles face many threats to their survival including incidental capture in fishing gear, or bycatch, egg collection by predators and climate change.
What was the cause of death for our turtle? Kemp’s Ridley turtles do not tolerate cold water below 8 degrees Celsius. East Hampton waters are currently about 10 degrees Celsius. So it seems that the turtle was too far north for its comfort zone. Note that it’s left front flipper seems to be missing or seriously mangled. This suggests that the turtle may have been injured, perhaps by fishing trawlers. Incidental take by shrimp trawlers in the gulf of Mexico is a recognized hazard for this species.
Finally, there is the possibility that ocean acidification from climate change has altered the food chain for this species as noted by OCEANA. Kemp’s Ridley turtle feeds on mollusks, crustaceans, jellyfish, fish, algae, seaweed, and sea urchins. But juveniles (such as our specimen) feed on crabs and on bay scallops.
It’s interesting that bay scallops in the Peconic bay have recently suffered a die-off discussed elsewhere on this blog and possibly related to ocean acidification.
Bottom line: you don’t have to look far to witness a species in trouble!
Interesting website where you can find data on any species: f.ex. Kemp’s Ridley turtle
I note that this species likes waters with high salinity (over 30 PSU), see above. The following map shows that our waters around Long Island have much lower average salinity (less than 25 PSU). Thus both the low temperature and the low salinity represent a hostile environment for Kemp’s Ridley Turtles.