Atlantic turtles threatened by man-made chemicals

A team from the College of Charleston, South Carolina, used hi-tech satellite transmitters to track migrant loggerhead turtles from Florida, up and down the U.S. Atlantic coast.

Deadly

And they found travelling turtles picked up potentially deadly pesticides, PCBs and other organic chemicals linked to cancer and brain problems.

The results of the groundbreaking research are published today in the magazine Environmental Toxicology and Chemistry.

Lead author Jared Ragland, from the College of Charleston, said: “The risks posed by persistent organic pollutants, known as POPs, remains largely a mystery for threatened loggerhead sea turtles.

“A clear understanding of these risks is critical for wildlife managers trying to maintain both the health of reproductively active individuals and a sustainable population overall.

“Our research is the first to examine POPs in the rarely studied adult male sea turtle and to couple contaminants measurements with satellite tracking. Although the turtle has been listed as threatened for more than 30 years, it is only now that we can begin to examine the effects of man-made chemicals on these animals in the wild.”

The team tagged 29 turtles near Port Canaveral, Florida, and carried out blood tests on 19 for a range of toxic chemicals.

The 19 were separated into two groups and tracked for 60 days.

Ten turtles travelled north along the US coast and nine stayed in Florida.

Turtles which migrated north had higher concentrations of dangerous chemicals in their blood.

Poisoning

Mr Ragland said: “Migrating turtles face cumulative poisoning as contaminants infiltrate the food chain through prey species such as crabs.”

Loggerheads are spotted offshore in Bermuda and turtle nests have been found on the island twice in the last decade.

The Bermuda Aquarium, Museum and Zoo (BAMZ) is looking after a hatch of loggerhead and green turtles washed up during the winter and spring.

They are believed to have come from Florida, although scientists admit they can’t be sure where they started their journey.

Dr Tony Knap, president and director of the Bermuda Institute of Ocean Sciences (BIOS), said PCBs continued to get into the air and seas through leakage from landfill sites.

He said: “It’s not unexpected that organisms like turtles and whales, which are at the high end of the ocean food chain, magnify up some of these compounds.”

BIOS scientists are to research how much PCB levels have dropped in recent years.