A rhinoceros auklet, a species which was part of a recent study on shorebird pollution. Via the NPS Olympic National Park site.
Scientists have finally found a better use for a bird's feather than sticking it in your cap—environmentalists are increasingly using marine birds to monitor water pollution.
That's because a small population of seabirds can eat marine life from hundreds of miles in any direction, and a bird's body retains pollutants in a way that fish and smaller animals don't.
As John Elliott, an environmentalist at Environment Canada, explains in a paper published today in Science, "In one afternoon at a seabird colony, a biologist can sample an area of ocean that would cost millions of dollars to investigate using a scientific vessel."
As fertilizers, heavy metals and plastics make their way up the food chain, they generally end up in seabirds, some of the ecosystem's top predators. Monitoring seabirds is also fairly easy, because they nearly always return to the same colony to mate. Chemical levels can usually be measured in the feathers, a particularly attractive option for environmentalists who don't want to, you know, kill animals.
Click to enlarge: This image from Elliott's paper shows how birds that feed near sources of pollution can concentrate chemicals at the top of the food chain. To quote the paper, "the graphs show data for two contaminants in rhinoceros auklet eggs at Lucy Island, northwest Canada: DDE, dichlorodiphenyldichloroethylene (a DDT metabolite), and PBDE, polybrominated diphenyl ethers (a ﬂame retardant)."
The practice is becoming more important as the Great Pacific Garbage Patch continues to expand. And by the way, recent evidence suggests that there are garbage patches forming in the Great Lakes as well.
Birds aren't just helpful for monitoring pollution when they're busy getting covered in oil or choking on plastic—because of the way their bodies process chemicals (very slowly), scientists are able to track pollution over hundreds of years in bird specimens preserved in museums.
"You can do studies on birds going back into the mid 1800s," Elliott said. "We can track the increases of heavy metals such as mercury from the Industrial Revolution on. You can even see decreases as a result of new regulations in the 1970s and a recent increase that some people have linked to more fossil fuel burning in Asia."
Sometimes, what scientists find in birds falls into the no shit category: Birds living near Japan's Fukushima nuclear reactor showed increased levels of radioactive isotopes in the wake of the 2011 disaster; birds living near the Gulf of Mexico were similarly impacted after the Deepwater Horizon spill.
And while everybody knew about the Great Pacific Garbage Patch long before albatross were turning up with bottle caps in their stomachs, seabirds can sometimes alert environmentalists to under-the-radar pollution threats. Using samples taken from seabirds, a study by Elliott's Environment Canada found that chemicals used in flame retardants used in clothing and other consumer products were making their way into the waterways.
"That's how these stories come to light," he said. "It's largely from analyzing the birds in the Great Lakes, but ours was the first to show it was spreading to coastal areas too."
Going forward, scientists are beginning to tag some birds with GPS trackers to monitor exactly where they're picking up these pollutants. Because they can cover thousands of miles in a season, scientists usually had to make educated guesses about where they were feeding.
"We didn't know specifically where they acquired the pollutants other than 'somewhere in the Pacific,'" Elliott said. "We had people volunteering on cruises and sitting on the deck all day counting birds to try to guess. Now, we know exactly where they're going."