Plastic tubes confound marine debris experts
By Jan TenBruggencate
Advertiser Science Writer
They are among the mysteries of the deep — simple plastic tubes that wash by the thousands, perhaps the millions, onto Hawai'i beaches.
Jan TenBruggencate • The Honolulu Advertiser
"It's one of the things we've never been able to identify," said John Naughton, a researcher with the National Marine Fisheries Service.
No one has been able to determine the origin of thousands of plastic tubes washing up on Hawai'i shores.
As part of its effort to identify sources of marine debris that harms wildlife, the service has worked with private and government agencies to figure out who's dumping or losing the stuff that entangles or chokes fish, turtles, seabirds and seals.
Thick nets, for instance, often come from trawl fisheries. Salmon gill netting operations often lose monofilament nets. Tangles of rope can come from all kinds of maritime operations. Abandoned plastic light sticks can come from the longline swordfish fishery.
Then there are the plastic tubes. Or straws. Or pea-shooters. Call them what you choose.
They're not all the same length. Some are as little as 5 inches long. Others as long as 10 inches. The most common length seems to be about 8.25 inches.
They bend a little, but they are not particularly flexible. They're not all the same width, but they're close. They range from about three-eighths of an inch to a half-inch in external diameter.
Internal diameters range from a quarter-inch to about seven-sixteenths.
The plastic tube walls can be as skinny as one-sixteenth of an inch, and as thick as one-eighth.
They're not all the same color. Some are black. Some are shades of gray, from quite light to nearly black. Some have bluish or greenish tints.
It has been suggested that they might be spacers between floats on fishing nets, but fisheries officials in Hawai'i have never seen a net like that, and the fisheries consultants they interview don't recognize them, either.
"I keep some in my office, and any time a fisherman comes by, I ask him, 'What are these?' " Naughton said.
So far, no one has known.
There were no responses to a query posted on a Web site, Beachcombers' Alert (www.beachcombers.org), operated by oceanographer Curt Ebbesmeyer, a marine debris expert.
Do these tubes have a fisheries application at all? Is there some military use? Is it possible they're not from a marine source at all? Are they washing out of a river somewhere?
"I'm sure that somebody out there knows what they are and is working with them every day. We just don't know who that is," said John Henderson, National Marine Fisheries Service biologist, who worked for several years with marine debris issues.
Naughton said he is convinced they are used for a fisheries purpose, but that they're not from around Hawai'i. "When you see them wash up, they're already old, so they've been around the North Pacific for a while," he said.
Anyone with a clue about the tubes can call Naughton at 973-2935, ext. 211.
Reach Jan TenBruggencate at jant@honoluluadvertiser.com or (808) 245-3074.
