Sea turtles are rare and gentle creatures. Occasionally I’ll cross paths with one when I’m diving in the Caribbean, and I respectfully pause to watch them calmly but purposefully cruising the depth. For one thing, I know they are holding their breath the whole time, but never look out of their element. They are air breathers like me but completely at home in the sea, their only time ashore crawling clumsily across a beach to lay eggs. They are vulnerable then, with most of their eggs doomed to be eaten by people or other predators. And as air-breathers they drown if entangled in fishing gear, intentionally or incidentally. As coral reefs decline, they lose habitat and food, and pollution takes a toll too. All the turtles in the Caribbean are endangered, and these quiet lone creatures soaring through blue reef waters are the survivors, for now.
The turtles I see most often are the smallest of them, the Hawksbill. They can descend as far as I do, a hundred feet deep, where the blue water turns deep indigo, searching for sponges to forage. Hawksbills tear off hunks of rough tissue, oblivious to the toxins and embedded prickly glassy spicules sponges use to protect themselves from grazers. This food makes Hawksbill meat dangerous if you eat too much of it, but the turtles are captured for food anyway, sometimes sold under the guise of Green turtles.
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For a few years we stayed at a dive op on the south shore of Roatan Island, Honduras. During that time a Loma Linda University biologist studying Hawksbill migration worked from there, and I learned quite a bit about their biology, lifestyle and problems from him. He was interested in juvenile Hawksbill behavior, their movements, range and feeding. Steve “Tortuga-man” (as the locals called him) persuaded fishermen to sell him turtles they collected rather than taking them to market. He and his graduate students cleaned them of parasites, made sure they were healthy, keeping them in the resort’s small lagoon (seawater flowing through it), tagging them and then releasing them. He tracked them over the years. I went out with him on one release day. He published his research (resweb.llu.edu/...) having gathered some useful information, but unfortunately the management of the dive op changed. The new manager wasn’t interested in turtle biology, so Tortuga Man went elsewhere in the Caribbean for his research (we didn’t return to Roatan, not happy with the new management for various reasons). Steve discovered, among other things, that juvenile Hawksbills are very specific in their choice of sponge foraging.
Sea turtles, except for Leatherbacks, have a hard outer shell that is part of their skeleton, fused to their spine. A major reason for the precipitous population crash of Hawksbills was hunting them for their shell. Hawksbills have a lovely irregular pattern of shades of amber, brown and gold that was used for decoration, combs, tools, etc. That trade is outlawed now but these late-maturing animals have a low rate of reproduction, and their numbers have not recovered. Once someone I was diving with found a scute: the temporary covering of each shell section that protects it, and is shed periodically. We admired the cast off scute and then tossed it back into the sea.
Green sea turtles are much less common here. I've only seen a few. Greens feed on algae, and their name comes from the color of their fat. Greens were eaten in great numbers for a while, and still are reputedly, but their population is so low there isn’t much of that now. The biggest and most abundant Green turtles I’ve seen was in Kauai waters. There honu are protected, with serious penalties for even touching one. As a result, there are very big old Greens cruising those waters.
Sea turtles go their own way, at home in the sea. I’d see Hawksbills swimming calmly through coral formations, paddling slowly down and upward. On this last trip Hawksbills would float for some minutes at the surface, bobbing in the swell. I watched them carefully from below. They spent very little of their surface time breathing. Mostly they’d gaze downward and around, almost as if they were checking out the shallower reef area — for yummy sponges? Or perhaps they were basking in the sun. The water temperature was a bit cooler this year, 80°F, which is good for corals, but a little harder on a reptile, which is exothermic (the same temp as its surroundings). A sunbathing session would feel good I’m sure. After a few minutes, the turtles would take one more gulp of air and descend into the deep.
The rarest turtle I’ve seen is the Loggerhead. These are big creatures, 4 feet long, hundreds of pounds. Individual Loggerheads tend to roam a particular area, and the dive guides alerted us to possible sightings. One day we were swimming along a reef and I looked up to see a great big turtle heading my way.
Her big front paddle-legs powerfully propelled her on her route. We were in her way. It’s a strange feeling to realize how insignificant you are around the inhabitants in nature — on land, wild animals avoid you. In the sea, humans are a disadvantage: slow and clumsy. Sea creatures - like fish, crabs, octopus, etc — know that. Generally they watch you and stay out of your reach. But to this old Loggerhead we were nothing. She kept swimming right at us. I ducked, and so did the divers behind me.
That big head contains powerful jaws. Loggerheads eat crabs, clams and other hard-shelled invertebrates.
I loved this moment. I love how she was in her element and I was a visitor. I love her grace and power and beauty. I love that she is safe there, in a Marine Park of Little Cayman Island, where there are extreme penalties for hunting sea turtles. She survived the hunting of her youth, and now a mature Loggerhead, is as likely to live out her turtle life as anywhere these days. Humans exploit and destroy the marine environment wherever they can. It speaks to kindness and wisdom and economic savvy that some governmental jurisdictions have chosen to protect sea creatures. There are many uncontrollable threats to sea turtles in all the tropical seas of earth. At least these turtles have a better chance than most.
Some sea turtle information sources:
www.seeturtles.org/…
marinebio.org/…
animals.howstuffworks.com/…
Time for your reports of the natural world in your neighborhood.
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