Arctic ivory gulls chemically polluted

This is a video of an ivory gull, ’30/12-06 … Langø Havn, Lolland Denmark’.

Gull sets Arctic pollution record for birds

Thu Sep 4, 2008 11:03am EDT

By Alister Doyle, Environment Correspondent

OSLO – A small Arctic gull has set a record as the bird most contaminated by two banned industrial pollutants, scientists said on Thursday.

Eggs of the ivory gull, which has a population of about 14,000 from Siberia to Canada, were found to have the highest known concentrations of PCBs, long used in products such as paints or plastics, and the pesticide DDT.

“Environmental poisons are threatening ivory gulls,” the Norwegian Polar Institute said in a statement of eggs collected off northern Norway and Russia. “Levels of PCB and DDT are higher in ivory gulls than in other Arctic seabirds.”

The long-lasting chemicals, swept north by prevailing winds and currents from industrial centers, often end in the Arctic where they build up in fatty tissues of animals, fish and birds.

A 2001 U.N. convention outlawed most uses of 12 so-called persistent organic pollutants after the chemicals were found in the breast milk of Inuit women and in polar bears. Levels of many of the “dirty dozen” in the Arctic have been falling.

“Ivory gulls are top predators, that’s a main reason why they have high levels of contaminants,” said Hallvard Stroem, of the Polar Institute. The gulls eat cod and other fatty fish and also scavenge dead seals or polar bears for a fat-charged diet.

“We’re not sure why the levels are higher than for other birds,” he told Reuters, adding there were no known local sources of the pollutants to explain the high concentrations.

PCBs, at up to 0.02 percent of the egg weight, were comparable with those found in some polar bears 20 years ago.

Previous studies show that the chemical pollutants can have effects on birds such as shortening lifespans or thinning of eggshells. Ivory gulls can live about 10 to 20 years.

The shrinking of Arctic sea ice in recent years, apparently because of global warming, also threatens the birds by reducing the size of their habitat. The gulls feed most around the fringes of the ice, where fish and plankton thrive.

“Climate change is an added stress — the ivory gull is dependent on the sea ice,” Stroem said.

The survey was carried out after reports that numbers of ivory gulls had plunged by 80 percent in Canada. Stroem said population trends elsewhere were not clear.

(Editing by Alison Williams)

Mercury pollution danger for Ivory Gulls. Full story here.

Levels of some persistent organic pollutants (POPs) regulated by the Stockholm Convention are decreasing in the Arctic, according to an international team of researchers who have been actively monitoring the northern regions of the globe: here.

Ivory gull in the USA: here.

Ross’ gull: here.

Researchers headed to the Arctic to help assess how seabird diets are changing as temperatures climb in the North. However, they did not expect to find plastic on the menu of the birds. 84 per cent of the Fulmars the researchers examined from two Arctic colonies had plastics in their guts. One had more than 20 bits of plastic in his gut: here.

Arctic and Antarctic: here.