As harbingers of ill fate in maritime lore, albatross have, themselves, come to be an indicator for modern-day oceanic pollution. Snatching up floating and near-surface food, Laysan albatross (Phoebastria immutabilis) in especially trash-strewn tides now pick up a more dangerous repast than they are accustomed to.
"With increasing amounts of marine debris, what once may have been 'optimal' foraging strategies for top marine predators, are leading to sub-optimal diets comprised in large part of plastic," wrote authors of a new paper on the subject.
The new paper, published online Tuesday in PLoS ONE, documents the new, deleterious diets that many of the wide-roving birds now have.
Ocean currents have brought together a big floating mass of trash, known as the Pacific Ocean's garbage patch. To see how different colonies of albatross might be affected, researchers attached tracking devices to dozens of adult birds from two groups of birds living about 2,150 kilometers apart—one on Oahu Island in Hawaii and another in Kure Atoll, northwest of the main Hawaiian islands, closer to the International Dateline. The researchers also collected regurgitated boluses from the chicks in these colonies to see how much unnatural flotsam the small fowl had been fed.
"We suspected that there may be some differences in the amount of plastic was ingested, but to discover that birds on Kure Atoll ingested 10 times the amount of plastic compared to birds on Oahu was shocking," Lindsay Young of the University of Hawaii and lead study author, said in a prepared statement.
Being fed more plastic and less natural food can stunt the growth of chicks and even kill some birds, the authors noted in the paper. The study's small sample size, however, did not allow researchers to discern how much of an impact the plastic might be having on the populations.
The team found that the birds from Kure Atoll, which brought back more plastic, spent a lot of time over the so-called western garbage patch between Asia and Hawaii, even though the Oahu birds lived close to bustling Honolulu and the more widely studied eastern garbage patch (between Hawaii and California). The plastic that the Kure Atoll birds had eaten appears to have largely come from Asia.
Among commonly recovered plastic items include lighters, fishing line and oyster spacers—likely discarded at sea by those in the fishing industry. Others have more commonplace trash, and one even had ingested an intact, sealed jar of face lotion.
"There was so many small plastic toys in the birds from Kure Atoll that we joked that we could have assembled a complete nativity scene with them," Young said. One Kure Atoll chick that died was found to have 306 pieces of plastic inside of it (see video below).
Image courtesy of USGS via Wikimedia Commons
Video courtesy of Paul Maurin, University of Hawaii, with narration by Cynthia Vanderlip, Hawaii Division of Forestry and Wildlife