Pollution Harms Top Marine Predators

Nonpoint source pollution comes from a wide variety of sources such as farms, cars, roads and highways, and lawns. This kind of pollution is ubiquitous and can pose a significant threat to wildlife.

At particular risk are higher trophic level species such as albatrosses, which are at the top of the food chain. These long-lived seabirds travel and forage over vast ranges and therefore accumulate chemicals distributed over large oceanographic regions. The black-footed species, however, breeds mainly on the Hawaiian archipelago.

The study researchers said that although measuring physiological changes in wild populations was challenging, measuring immune function was an important step in linking changes in biomarkers to contaminant exposure. The elevated blood levels found in the albatrosses were due mainly to mercury and various organochlorines.

Because the North Pacific is an area of high biological productivity, results from the study are important for other species as well. Of particular concern is the health of other predators in the high-latitude regions of the Arctic, such as seabirds, polar bears, and other marine mammals, that are exposed to contaminants in the marine environment.

This study is published in the latest issue of Environmental Toxicology and Chemistry.