How the Gulf Oil Spill May Affect Sea Turtles

During the Age of the Dinosaurs, the sea teemed with marine reptiles. But when the dinosaurs disappeared 65 million years ago, only a few reptiles remained in the sea—sea turtles, sea snakes, saltwater crocodiles, and marine iguanas.

Kemp's Ridley turtle, courtesy of www.turtlejournal.com

These ancient sea creatures have survived unto the 21st century, but most of the seven species of sea turtles are threatened or endangered. One of the most critically endangered sea turtle species—the Kemp’s Ridley—may be most affected by the recent Gulf Oil spill. Kemp’s Ridleys are one of the few sea turtle species that don’t do a lot of roaming. They stay mostly in the Gulf of Mexico.

Kemp’s Ridley (along with Olive Ridleys) are the smallest sea turtles. They are known for their unusual nesting behavior called an arribada, in which hundreds or even thousands come ashore at the same time to lay their eggs. In the 1940s, over 40,000 turtles were filmed coming ashore at one time to lay eggs. By 1980 that number had shrunk to just a few thousand. Causes of their decline are drowning in shrimp trawls, longlines, and gillnets, pollution, egg collection, hunting, degradation of their nesting sites, habitat loss, and other human-caused problems.

Shrimpers are now required by law to attach Turtle Extruder Devices (TEDs) to their nets to prevent entangled turtles from drowning. TEDs are a grid of bars with an opening at the top or bottom fitted into the neck of the shrimp trawl that allows small animals like shrimp to slip through the bars and be caught, while larger animals such as sea turtles strike the bars and are ejected.

In recent years the Kemp’s Ridley sea turtles have made a recovery. In 2009 there were 197 documented nests on the Texas coasts. At Rancho Neuvo and in neighboring Mexico beaches, 8000 females nested. Unfortunately the recent oil spill may cause a severe setback in the recovery of these turtles.

How Oil Harms Turtles*

Like marine mammals, sea turtles need to come to the surface to breathe air. If turtles surface in an oil slick to breathe, oil will affect their eyes and damage airways or lungs. Imagine if you dove into a pool with oil on the surface. When you came up for air, you couldn’t help but swallow and breathe in the oil.

Sea turtles will be affected by oil through contamination of their food supply.

Sea turtles are marine (ocean) animals, but have a crucial tie to the land. Females must come ashore to lay eggs. After they lay the eggs, female turtles cover the nest (a deep hole they have dug in the sand with their flippers) and return to the ocean. The baby turtles hatch from eggs and must fend for themselves as they scramble from the nests to the ocean.

Nesting sites covered with oil can lead to the following problems:

•Digestion/absorption of oil through food contamination or direct physical contact, leading to damage to the digestive tract and other organs.

•Irritation of mucous membranes (such as those in the nose, throat and eyes) leading to inflammation and infection.

•Eggs may be contaminated, either because there is oil in the sand high up on the beach at the nesting site, or because the adult turtles are oiled as they make their way across the beach to the nesting site. Oiling of eggs may inhibit their development.

•Newly hatched turtles, after emerging from the nests, make their way over the beach to the water and may become oiled.

In addition to the oil, thousands of gallons of “dispersants” have been dumped into the Gulf in an effort to break up the oil spill. It is unclear what chemicals are in these dispersants, which will now become part of the food chain—and could contaminate the seafood we eat as well.

So far, scientists have been unable to predict the direction of the spill. It depends on weather/wind patterns, possible storms, and many other variables. If the oil gets into the loop current that swings northeast from the Gulf, it may reach the Florida Keys and eventually the Eastern Seaboard. If this happens, loggerhead turtles that nest on southeastern beaches may also be severly affected by the spill.

Several years ago, I saw a loggerhead sea turtle lay her eggs on a beach on the east coast of Florida in the shadow of Cape Canaveral—an awesome experience  I will never forget. I witnessed something that had been happening for millions of years. Humans have been around for a tiny fraction of the time that sea turtles have inhabited this planet. It is our responsibility to help protect them, especially now, in the face of this potentially devastating oil spill.

The Sea Turtle Restoration Project has daily updates about sea turtles and the oil spill, and includes suggestions for how you can help.

The Carribean Conservation Corporation: Sea Turtle Survival also has good information about how oil affects sea turtles, and has lots of general information about sea turtles. I have adopted several turtles from this organization.

*Note: most of the information about sea turtles and oil came from the Australian government website, Effect of Maritime Oil Spills on Wildlife.