Having been here a week it’s about time to write a little more about the turtles and Ocean Spirits, the organization I’m volunteering with. First the turtles.
The predominant species of sea turtles that come to Levera beach are Leatherbacks (Dermochelys coriacea). Occasionally there are Hawksbill turtles too, but those are very shy and go back to the sea at the slightest perceived threat or intrusion. The Hawksbill mainly nest on other smaller islands, where later in the season expert divers from Ocean Spirits catch them to tag and thus keep track of their numbers.
Leatherbacks, the largest of all sea turtles, are between 1-2 meters long and weigh on average 250-700 kgs. They reach this enormous size on a diet of jellyfish, thus controlling jellyfish populations. Unfortunately, floating plastic looks a lot like jellyfish, hence their ingestion of it, which can kill them. They have a vast worldwide ocean distribution – Atlantic, Pacific, Indian and Mediterranean. They are ideally suited to cold water, diving and swimming great distances (they migrate thousands of kilometers between breeding and feeding grounds). They are unique reptiles in that they maintain their body temperature (being air-breathing, they are almost constantly swimming), and have a shell or carapace that is more leathery than bony, which enables it to compress when they dive (sometimes over 1200 m).
Females return to the beach where they were born to nest. This fact always amazes me – how on earth do they know where to go, many years later after swimming up to 7000 km with no road signs? I still get lost in Boston and I’ve been living there for over 3 years! Perhaps this is because road signs are almost as rare in Boston as they are in the Atlantic. Males on the other hand, spend their entire lives in the ocean after they’ve passed that first perilous test of digging out of the egg chamber and getting to the water. Only about 50-60% of laid eggs hatch, and after that many are lost to predation by birds, dogs, and other animals. We were shown video footage of even a crab running off with one. There are further dangers in the water from fish and cephalopods until they mature. Only approximately 1 in 1000 survives to adulthood. What happens in the intervening years between hatchlings reaching the ocean and the first time females return to nest remains a mystery.
As you may expect, they are also killed by human predation and activities – poachers dig up the eggs to eat or use as aphrodisiacs, rarely are the turtles used for meat. Turtle eggs aren’t very expensive on the local market, so other than these superstitious beliefs and a lack of awareness, there doesn’t seem to be a large incentive for their sale. Once they find a nest, poachers take all the eggs. Turtles are also killed by longline fishing hooks and lines, fishing nets, or are hit by boats. Their nests are affected by sand mining and coastal developments (resorts). These reasons are why the Leatherback is critically endangered, as are many other turtle species.
Thankfully, on Levera beach, the third largest nesting site for Leatherbacks in the Caribbean, there is almost no poaching due the work of Ocean Spirits. Teams are on the beach every night during nesting season, and both interfering with nesting turtles and of course poaching are against the law, with police backup available where necessary. Coastal development is a big problem here as elsewhere. A resort is coming up behind Levera beach, where they are planning to install a jetty. After clear cutting the forest, clay eroded down onto the beach. Hatchlings cannot dig through clay like sand, so they suffocate. Also, bright lights prevent turtles from coming onto the beach to nest. The Atlantic population however is in far better condition to the Pacific population, which is virtually extinct for the same reasons as they are endangered here.
Despite the gloom, there is hope as the numbers of nests on Levera beach has increased dramatically in the last decade or so, and with a dedicated staff, I have no doubt that the excellent work being done here will continue.
You can read more about them here:
http://www.nmfs.noaa.gov/pr/species/turtles/leatherback.htm
http://animals.nationalgeographic.com/animals/reptiles/leatherback-sea-turtle/
Ocean Spirits: http://www.oceanspirits.org/
Leatherbacks, the largest of all sea turtles, are between 1-2 meters long and weigh on average 250-700 kgs. They reach this enormous size on a diet of jellyfish, thus controlling jellyfish populations. Unfortunately, floating plastic looks a lot like jellyfish, hence their ingestion of it, which can kill them. They have a vast worldwide ocean distribution – Atlantic, Pacific, Indian and Mediterranean. They are ideally suited to cold water, diving and swimming great distances (they migrate thousands of kilometers between breeding and feeding grounds). They are unique reptiles in that they maintain their body temperature (being air-breathing, they are almost constantly swimming), and have a shell or carapace that is more leathery than bony, which enables it to compress when they dive (sometimes over 1200 m).
Females return to the beach where they were born to nest. This fact always amazes me – how on earth do they know where to go, many years later after swimming up to 7000 km with no road signs? I still get lost in Boston and I’ve been living there for over 3 years! Perhaps this is because road signs are almost as rare in Boston as they are in the Atlantic. Males on the other hand, spend their entire lives in the ocean after they’ve passed that first perilous test of digging out of the egg chamber and getting to the water. Only about 50-60% of laid eggs hatch, and after that many are lost to predation by birds, dogs, and other animals. We were shown video footage of even a crab running off with one. There are further dangers in the water from fish and cephalopods until they mature. Only approximately 1 in 1000 survives to adulthood. What happens in the intervening years between hatchlings reaching the ocean and the first time females return to nest remains a mystery.
As you may expect, they are also killed by human predation and activities – poachers dig up the eggs to eat or use as aphrodisiacs, rarely are the turtles used for meat. Turtle eggs aren’t very expensive on the local market, so other than these superstitious beliefs and a lack of awareness, there doesn’t seem to be a large incentive for their sale. Once they find a nest, poachers take all the eggs. Turtles are also killed by longline fishing hooks and lines, fishing nets, or are hit by boats. Their nests are affected by sand mining and coastal developments (resorts). These reasons are why the Leatherback is critically endangered, as are many other turtle species.
Thankfully, on Levera beach, the third largest nesting site for Leatherbacks in the Caribbean, there is almost no poaching due the work of Ocean Spirits. Teams are on the beach every night during nesting season, and both interfering with nesting turtles and of course poaching are against the law, with police backup available where necessary. Coastal development is a big problem here as elsewhere. A resort is coming up behind Levera beach, where they are planning to install a jetty. After clear cutting the forest, clay eroded down onto the beach. Hatchlings cannot dig through clay like sand, so they suffocate. Also, bright lights prevent turtles from coming onto the beach to nest. The Atlantic population however is in far better condition to the Pacific population, which is virtually extinct for the same reasons as they are endangered here.
Despite the gloom, there is hope as the numbers of nests on Levera beach has increased dramatically in the last decade or so, and with a dedicated staff, I have no doubt that the excellent work being done here will continue.
You can read more about them here:
http://www.nmfs.noaa.gov/pr/species/turtles/leatherback.htm
http://animals.nationalgeographic.com/animals/reptiles/leatherback-sea-turtle/
Ocean Spirits: http://www.oceanspirits.org/
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