The stories are heartbreaking. The pictures are grisly. A sea otter choked to death on plastic six-pack rings; a dead endangered turtle, its gut filled with plastic toys; a beached gray whale with more than 20 plastic bags, surgical gloves and pieces of plastic in its stomach.
Nearly indestructible, plastic pollution is taking an alarming toll on Earth's wildlife, particularly marine animals.
“Countless marine animals have been killed or harmed by marine debris primarily because they either become entangled in it or they mistake [it] for food and ingest it,” noted a Greenpeace report.
Marine debris has affected at least 267 species worldwide, including 86 percent of all sea turtle species, 44 percent of seabird species, 43 percent of all marine mammal species and numerous fish and crustaceans. It's difficult to estimate how many animals perish from plastic debris every year, but the number is often estimated at 100,000, though many scientists believe it is much higher.
Discarded plastic fishing line and nets are especially lethal. Indeed, long after nets have been lost or abandoned, they continue to trap and kill fish and other marine creatures, known as “ghost fishing.” During last year's one-day International Coastal Cleanup, the Ocean Conservancy's volunteers in 108 countries found 336 marine birds entangled in debris, 120 of which were alive and released. A seal was found dead, entangled in plastic fishing line.
Pelicans, albatross and other sea birds often mistake bits of plastic for food. A documentary shows seagulls gulping down plastic bags and workers clearing fields of dead albatross, their stomachs filled with plastic debris. (Watch the video at: www.utne.com/Wild-Green/Our-Plastic-Nightmare-Now-on-Video-7364.aspx?utm_content=05.21.10+Great+Writing&utm_campaign=Emerging+Ideas-Every+Day&utm_source=iPost&utm_medium=email).
“Animals that eat trash can choke or die a slow death because the debris clogs their digestive tracks,” said an Ocean Conservancy report. “Or they may starve because they feel full and stop eating altogether.”
Thousands of albatross, like this one in San Rafael, Calif., are thought to die each year from ingesting plastic. (AP Photo/NOAA/Jacob Asher)
Sea turtles may mistake floating plastic bags for jellyfish. In one study 15 percent of the loggerheads examined had plastic in their stomachs. In another study, 62.5 percent of Alaskan sea birds had ingested plastic. Plastic fragments — including production pellets, party balloons, fishing line and plastic film — were found in 71 percent of 190 northern fulmars, gull-like sea birds common to the Arctic, that were found washed up along the shore in 2003.
Researchers have begun studying whether plastic-ingesting marine life — from tiny zooplankton to larger mammals — absorb toxic organic compounds such as PCBs and other substances found in plastic that are now thought to affect animals' reproductive systems.
“In laboratory studies crustaceans and amphibians that had eaten plastic pieces exhibited impaired reproduction,” pointed out the Ocean Conservancy. “Scientists have noted changes in both behavior and hormone levels in fish exposed to plasticizers,” or additives that make plastics stronger and more flexible.
More research is needed to determine the danger to humans from ingesting plastic-contaminated fish, according to experts.
Plastic is also a threat to land-based animals, from sacred cows in India to raccoons and birds of prey. For example, “hundreds” of camels die each year from starvation after eating plastic bags that eventually calcify into heavy “rocks” in their stomachs and make it impossible for them to eat, said Ulrich Wernery, scientific director of Dubai's Central Veterinary Research Laboratory. “Every day we have a camel that has died in a camel camp. One in every two camels dies from plastic.”
An autopsy on an Australian crocodile found in a tourist area turned up 25 plastic bags and a plastic wine cooler bag in its stomach. “Because the material had compacted solidly in its stomach it was unable to digest food,” a government spokesman said.” And in India, more than a dozen cows were dying each day in Lucknow. Autopsies revealed that the cows, considered sacred in the Hindu religion, had eaten dozens of plastic bags, which had blocked their digestive systems.
“It's shameful that so many animals are dying from plastics,” says Charles Moore, the American sailor who has helped focus the world's attention on the huge amount of floating plastic in the Pacific Ocean. “Our plastic footprint is taking a greater toll on marine life than our carbon footprint is.”
— Robert Kiener