At sea or on the coast we often find plastic trash scattered about. In Kimalo Pointis located on the island of Hawaii, even the plastic pieces found at a depth of one meter below the surface of the sand.
"In some other beaches, it is difficult to distinguish between sand and plastic," said Nicholas Mallos, marine debris researchers at NGO Ocean Conservancy told LiveScience, January.
To determine the level of litter pollution in the sea, sea bird scientists use as a measuring tool. Sea birds, including pelicans and gulls, is the top of the food chain. They absorb toxins and pollutants contained in the fish they eat. Because seabirds foraging in the vast sea area, but always returned to the same location each year to breed, they are supplying the samples of pollutants from a wide geographic area to researchers.
"They fly over the ocean spread over the year so you could say they took samples of pollution for us," said John Elliot of Environment Canada in the journal Science, May 3, 2013. "As long as they find food, they are exposed to contamination, especially species that are bioaccumulative we seek."
Monitoring of toxins in marine bird, the bird is not lethal. Scientists using feather samples, blood, oil, and tissue samples without killing the birds. Sample is adequate to measure the pollution that occurs.
Birds are often found dead with stomachs full of plastic. This indicates an increase in ocean contamination from sewage fishermen and beach visitors.
Monterey Bay Aquarium in California estimates that about 1 million sea birds, plus 100,000 marine mammals and turtles die from ingesting plastic every year.