Saturday, December 5, 2009

Marine Turtles in New Jersey Waters

Green turtle surfacing for air
In New Jersey, we have 4 marine turtles that are protected.
  1. Atlantic loggerhead turtle, Caretta caretta - NJ Status: Endangered, Federal Status: Threatened
  2. Atlantic leatherback turtle, Dermochelys coriacea, NJ & Federal: Endangered
  3. Kemp's ridley turtle, Lepidochelys kempi, NJ & Federal: Endangered
  4. Atlantic green turtle, Chelonia mydas, NJ  & Federal: Threatened
  5. Atlantic hawksbill turtle, Eretmochelys imbricata, NJ & Federal: Endangered
Last week, cold-stunned Kemp's Ridley sea turtles began to wash up on Cape Cod beaches which unfortunately marks the beginning of the turtle stranding season here in the Northeast.

As water temperatures dip below 50 degrees, it becomes too cold for the sea turtles. These species should have moved south for the winter by now, but some marine reptiles get fooled by ocean anomalies around Cape Cod and Long Island.

Turtles described as "cold stunned" are in a torpid state with heart rates slowing down to as low as one beat a minute. They can appear to be dead, but this state actually allows the turtles' bodies to survive as the turtles can bury themselves in the mud on the bottom of the sea and survive for a few weeks in waters below 50 degrees.

Of course, they can survive the entire winter that way, so stragglers that wash up on the beach can be rescued by volunteers.

Unlike land turtles from which they evolved more than 150 million years ago, sea
turtles spend almost their entire lives in the sea. When active, they often come to the
surface to breathe, but can remain underwater for several hours at a time while resting.

Leatherbacks can dive to more than 3,000 feet below sea level. Their habitat preference is based on their preferred diet. Adult green turtles are herbivores, or plant eaters. All the other sea turtles are either carnivores (meat-eaters) or omnivores that eat both plant matter and meat.

Kemp's Ridley

The Kemp's Ridleys, which hatch off the coast of Mexico, are the most endangered of the sea turtles in our water. Kemp's ridley is the smallest of all sea turtles. From above, the short, chunky shell appears broadly heart-shaped to nearly round, with high vertebral projections and serrated edges. Adults weigh between 35 and 42 kg (77-92 lbs.).

The leatherback is the largest of all sea turtles. In fact, the leatherback is one of the largest living reptiles (only some species of crocodiles are larger). It is easily distinguished by its black, leathery skin, huge, spindle- or barrel-shaped bodies and long flippers. Adults generally weigh between 290 and 590 kg (638-1298 lbs.), but can weigh up to 2,000 pounds.

The most colorful sea turtle, the medium-sized hawksbill turtle has an elongated, oval shell
distinguished by overlapping scutes on the carapace.Color varies widely, from very bright colors to heavy dark brown (in the eastern Pacific).

Overharvesting of eggs for food, intentional killing of adults and immatures for their shells and skin and incidental drowning in commercial fishing gear are primarily responsible for the worldwide decline in sea turtle populations. Coastal residential and resort development has also degraded nesting habitat, and pollution of oceans threatens foraging habitats.

The federal government listed the Kemp's Ridley as endangered in 1970, the same year it also listed hawksbill and leatherback turtles as endangered. In 1978, it listed loggerheads as threatened and green turtles as threatened and, in the case of the green turtle's Florida and Mexico breeding populations, as endangered. New Jersey classified the species in 1979.

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