Marine debris, including lost and discarded fishing gear, is found on remote coasts throughout Alaska, sometimes in staggering volumes, speakers told participants at Saturday’s Earth Day event at the Chilkat Center.
On the Bering Sea’s Pribilof Islands, there are 172 pounds of it for every 100 yards of coastline, according to a recent study by the Alaska Marine Stewardship Foundation.
Dave Gaudet, a biologist and marine debris analyst, has worked on foundation efforts that removed more than two million pounds of debris from Alaskan beaches since 2009. But the cleanups have reached only 6 percent of the state’s coastline.
Plastics are especially a concern, as they contain chemicals that can break down and `release toxins into the ocean. Even non-toxic plastic is a threat to fish and sea birds that can mistake it for food, ingesting fatal amounts.
Gaudet has dug up four-wheelers buried in the sand at Brevig Mission, fished computer monitors out of water near Craig and hauled tons and nets, line and giant-sized flotsam buried or entangled on Bering Sea beaches.
“It’s amazing we can get anything done on some of this. Trying to move some of this debris is one of the most difficult things you can think of,” he said.
Gaudet showed slides of pens full of fishing buoys, car-sized mounds of “ghost” nets and debris requiring chainsaws and heavy equipment to haul off. In recent years, Bering Sea fishermen have been recruited to help in the effort to remove debris from remote spots like Savoonga and Nelson Lagoon.
Soft foams like Styrofoam that break down quickly are the most immediate concern, but even hard plastics break down over time and, in coastal areas, make their way back into the ocean, Gaudet said.
Flotsam such as the 1.5 million tons of items set afloat by the 2011 tsunami that devastated Japan makes headlines, but “stuff keeps getting thrown into the ocean” from less prominent sources, said Lauren Bell of the Sitka Sound Science Center. The center recently inherited the foundation’s marine debris work.
Bell cited a recent article in the journal Science that estimated the annual volume of plastics entering the ocean at 4.8 to 12.7 metric tons.
A more insidious concern than large debris are “microplastics,” bits less than five millimeters long that are ingested by the smallest sea life like krill, and bio-accumulate in larger animals, Bell said. Ingested by juvenile salmon, they can make fish feel “full,” and stop eating, sapping energy.
Microplastics are released during car tire wear and the washing of certain fabrics, as well as in cosmetics. An estimated 240,000 metric tons of them enter the ocean each year. “We are all sloughing off plastics one way or another and they are all washing into the ocean,” Bell said.
Bell said consumer choices – like limiting use of disposables such as plastic straws – can help reduce volumes of micro-plastics. There doesn’t appear to be any effort related to limiting tiny shreds off car tires, Bell said.
For more information, contact the Sitka Sound Science Center at sitkascience.org.