Turtle Conservation

Sea turtles are thought to have evolved over 208 million years ago, although some estimates suggest it is as much as 230 million years ago! Either way, they have outlived the dinosaurs!

Unfortunately, their reign over our oceans is crashing down. All species of marine turtle are now endangered, the Hawksbill, Leatherback and Kemp’s Ridley critically so. Despite their protection under CITES, illegal trade in turtle eggs and products continues to ravage their populations. The natural life cycle of marine turtles is tough enough without the added pressure from humans, and it is no wonder their numbers are drastically declining.

Natural threats

Turtles are predated upon at every stage in their life cycle! Firstly, the mother is vulnerable as she crawls up the beach to lay. She is slow and clumsy on land, unable to avoid any attack from large predators. On top of that, she goes into a trance when she lays and is unaware of her surroundings.

Once buried, the eggs, a source of valuable protein, are vulnerable to invasions of Ghost crabs, red ants, and other predators in the sand. If the yolk is spilled or a hatchling starts to rot, bacterial and fungal infection may wipe out the remaining eggs. Additionally the smell may attract dogs, cats, monkeys, monitor lizards and more, to dig up the nest and eat the eggs.

When the eggs hatch, the hatchlings are soft-shelled and an easy target. Here is an Oriental Whip snake grabbing one of our hatchlings right out of the hatchery! We managed to save it from the snake, but who knows if it survives its first few months at sea, with fish and sea birds able to eat through its soft carapace (shell).

Even as adults, when their carapace is hard, predators like sharks and salt-water crocodiles have enough power in their bite to crush a fully developed adult! And they still have to deal with human pressure!

Human Threats

Humans assault both ends of the turtle populations. In the past, eggs were collected in isolated area’s with few resources and eaten for a source of protein. Presently, with the decline in populations, this is no longer sustainable, and no longer distinct from the black market trade of these “beach eggs” as a delicacy, a luxury and not necessity.

The turtles themselves are also poached for their meat, fat, shells and leather. Hawksbills are especially targeted because of their beautiful golden or dark brown shells, used for decoration and supposed health benefits. The traditions that involve the exploitation of turtles are long-standing and difficult to stop, especially with a lack of alternative income. Hopefully, with increased awareness these products will start to be looked upon with distaste, because when the demand stops, the killing will too!

Unfortunately, the threat of intentional fishing of turtles is far out-weighed by the problems of by-catch due to various fishing methods. Long-line fishing, for example for Tuna, has been noted as one of these methods. However, arguably the most damaging (and not just to turtles) are the nets used in shrimp trawling and fishing. If caught, turtles are unable to come to the surface to breathe (as all reptiles must), and they will suffocate.

TEDs or Turtle Exclusion Devices are a welcome technological advance. Shrimp nets are equipped with a metal grid, that allows shrimp to pass through and be caught, but is pushed open by a large animal such as a turtle, to allow it to escape! Before the TED devices were used, it was estimated that over 47,000 sea turtles were caught each year by the US shrimp fleet alone, of which a minimum of 12,000 died.

Many turtles, especially Leatherbacks, eat jellyfish as part of their diet. Floating plastic bags look uncannily like plastic bags, and have obvious horrific consequences. If the turtle does not suffocate and swallows it, the plastic will clog up its intestines and cause further damage. Ingested fishing line causes similar problems.

Oil spills have wide spread and long lasting effects, including blocking the throats and jaws of turtles. Boat strikes are a violent and slow cause of death for many turtles across the oceans.

Marine turtles serve as indicator species for the health of a marine environment, and their waning populations should be a wake-up call for us to literally clean up our act!

3 responses

31 12 2008
johnny

F3lJqk Thanks for good post

5 05 2009
Ashley van den Heever

Hi

I am undergraduate student undertaking a Biomedical Science degree at The University of Queensland. One of the assignments I am currently doing is on the effects of urbanisation on Marine turtles. I was wondering if you had any images of turtles, when they are unharmed and when they are harmed that I would be able to utilise in a video. Of course, I would definitely acknowledge that they came from you.

Yours sincerely

Ashley van den Heever

8 01 2011
John

Great blog, bookmarked for later use.

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