There are only seven marine turtle species in the world and three of them are critically endangered.
‘For more than 100 million years marine turtles have covered vast distances across the world’s oceans, performing a vital and integral role in marine and coastal ecosystems. Over the last 200 years human activities have tipped the scales against the survival of these ancient mariners. Urgent global action is needed to ensure their future.’ – WWF
These turtles live in tropical and subtropical oceans eating sponges, salps, jellyfish and sea plants such as seagrass. Scientists are in a current debate about whether the Atlantic green turtle and Eastern Pacific green turtle are subspecies or separate species. It is one of the largest sea turtles. The green turtle (so named for the colour of its cartilage, not its shell) is endangered and are threatened by overharvesting, hunting, by-catch and loss of nesting sites. There are estimates that the population of green turtles has dropped anything between 48% and 65% in the last 100-150 years. Green turtles are important to maintain seagrass habitats making them more productive. Seagrass serves as habitats for many fish and invertebrates.
The green turtles is hunted and its eggs collected. This collection is predominantly for human consumption. The turtles are killed for medicine and ceremonies even though the turtle is protected. Uncontrolled coastal development has led to the reduction of beach nesting sites for these turtles who will lay 100-200 eggs in the sand for them to hatch later.
Kemp’s Ridley Turtle
Compared to the green turtle, the Kemp’s ridley turtle is the smallest and the most endangered turtle. It is critically endangered. There are estimated only around 1000 of these turtles in the wild. The reason for their perilous situation is, like the green turtle, their eggs have been overharvested and they die as a result of by-catch. They are typically found in the Gulf of Mexico. Like the green turtle they will migrate thousands of miles to reach a beach nesting site to lay hundreds of eggs in the hope that a few will survive.
These turtles are considered critically endangered. There are around 20,000 – 23,000 nesting females. The Hawksbills turtle is found throughout tropical oceans. These turtles eat sponges and provide an important service by removing these sponges from the reef surface for fish to find access into the reef. Despite protection from CITES and other national laws, the Hawksbill turtle is under threat from illegal wildlife trade. Their shells are manufactured into tortoiseshell products to sell. Asia is providing the market for these products. Like the other turtles, they too suffer deaths from by-catch and overharvesting.
The Leatherback turtle is critically endangered. There are around 20,000 breeding females. They are the largest sea turtle and unlike the other turtles, they have a leathery carapace instead of a bony shell and are found in cooler waters nearer the poles. Like all the other turtles they too suffer from overharvesting, wildlife trade, habitat loss, pollution, climate change and by-catch.
These turtles are named for their large heads and strong jaws. They live in tropical and subtropical oceans. These turtles are endangered. Since 1978 they have been on the endangered list due to continual threats that all the turtles suffer from even though they are the most abundant turtle. The greatest threat to loggerhead turtles is by-catch.
Olive Ridley Turtle
Olive Ridley turtles are related to the Kemp’s turtle and are both the smallest. The only difference is that the Olive Ridley is found in warmer waters. These turtles are quite abundant. It is estimated that there are around 800,000 breeding females, but the population is declining more rapidly than the other turtles. They nest in only a very few places and this makes them very vulnerable. Like all the other turtles, they are vulnerable to many human factors such as by-catch.
Flatback Sea Turtle
This sea turtle has the most restricted habitat than any other turtle. They are found from northern Australia to Papua New Guinea and Indonesia. Out of all the sea turtles, very little is known about this turtle. They are considered to be vulnerable but because so little is known about them, it may be likely that they are endangered.
Around 1 in 1000 sea turtles will make it to adulthood. The eggs offer food for birds, crabs and other marine animals. However, it is human influence that is really affecting the turtles right now. A threat that has not been fully understood is that of climate change. The surrounding temperature of the sand around the eggs affects the sex of the hatchlings. The sand is becoming warmer as climate change ever grips our planet and this is causing a huge influx of females hatching rather than males. This is affecting the overall breeding activities. These animals have survived millions of years and now the actions of humans means that the turtles cannot deal with the threats facing them today.