Hawai'i's Environment
Floating plastic tubes a threat to albatrosses

By Jan TenBruggencate
Advertiser Columnist

Laysan albatrosses may be the species most seriously affected by discarded or lost plastic tubes from the Japanese oyster fishery.

The giant seabirds are notorious for snagging all kinds of floating debris off the sea's surface.

"The albatrosses cannot distinguish these as they float on the open sea surface from their preferred prey," which include squid and cuttlefish, said Rick Steiner, a biologist and professor with the University of Alaska Marine Advisory Program.

Often, adult albatrosses can regurgitate and get rid of the stuff along with squid beaks and other indigestibles.

Most fatalities come among the chicks, which are fed plastic debris along with the other food their parents regurgitate for them. The plastic fills their bellies until they can't take any real food.

At nesting islands, it is not uncommon to find weathered carcasses of albatross chicks with little piles of plastic among the bones.

"We found many dead Laysan albatrosses on Laysan Island whose rib cages were stuffed with all sorts of plastic and floating debris: medicine bottles, light bulbs, toys, bottle caps and many of these plastic tubes," Steiner said.

The hollow plastic tubes, which wash up on beaches in Japan and throughout the Hawaiian Islands, are up to about 8 inches long and about a half-inch in diameter. They come in black, green and blue.

Their origin was a mystery to most Pacific researchers until earlier this year, when it was determined they are spacers used by the Japanese coastal oyster fishery to keep clusters of oysters apart as they are suspended on ropes under giant bamboo rafts.

Sometimes the rafts break loose in typhoons, releasing hundreds of the floating plastic tubes into the vast North Pacific current.

The tubes were once made of polyvinyl chloride, or PVC, which sinks in water. But in recent years, the fishery has been using polyethylene, which floats. That's why the tubes suddenly appeared on the surface of the seas.

Steiner said he has already been in touch with Japan consular and fisheries officials to discuss ways of removing the source of the albatross-killing tubes.

"We will be exploring the options of having them switch back to PVC material for the spacers in their oyster gear or another sinking or degradable material," Steiner said.

Steiner wrote Japanese fisheries officials: "This simple change in gear used by the oyster growers would ultimately eliminate one of the most prevalent plastic debris items in the diet of North Pacific albatrosses, and save many of them from an untimely death. And, it could be done at minimum expense for the oyster growers."

Jan TenBruggencate is The Advertiser's Kaua'i bureau chief and its science and environment writer. Contact him at (808) 245-3074 or e-mail jant@honoluluadvertiser.com.