Fish & Wildlife | Ecotrope

Are Gill Nets Killing Too Many Birds?

Ecotrope | Oct. 8, 2012 6:59 a.m. | Updated: Feb. 19, 2013 1:29 p.m.

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Last week I reported on some of the motivations behind Oregon’s ballot measure to ban gill nets and Gov. John Kitzhaber’s plan to remove gill nets from the Columbia River channel.

The two primary reasons I heard from supporters of the governor’s plan was that they want to see more selective fishing – methods that allow fishermen to avoid catching protected wild salmon and steelhead – and an economic boost to the sportfishing industry.

But I got a note from Steve Pedery, conservation director for Oregon Wild. He said I didn’t note another reason why environmental groups want to get gill nets off the Columbia.

Gill nets don’t just kill protected wild fish, Pedery said. They also kill other wildlife such as birds.

A derelict gill net found by the U.S. Fish and Wildlife Service Puget Sound Coastal Program with all kinds of dead sea life entangled in it.

A derelict gill net found by the U.S. Fish and Wildlife Service Puget Sound Coastal Program with all kinds of dead sea life entangled in it.

And it isn’t just the gill nets that are attached to boats that kill birds, he said. It’s also the nets that get snagged on the bottom of the river and left to “ghost fish” until someone removes them. You can see an example in the video above. Bruce Polley is a member of the Coastal Conservation Association, one of the groups behind the ballot measure to ban gill nets.

Pedery sent me a story about derelict gill nets around Puget Sound, where the Northwest Straits Foundation estimates ghost fishing kills 30,000 marine birds every year, as well as fish and other creatures.

He also sent me this story from Bird Life International that cites studies of gill net impacts on birds around the world. Between 1993 and 1999, one study found Japanese boats alone killed around 482,500 seabirds.

Neither of those stories account for the wildlife impacts of the gill net fishery on the Columbia River.

I asked gill netter Greg Johnson about the issue when I was out on his boat last night. He said he’s never caught a bird, but he has responded to two calls from the Washington Department of Fish and Wildlife over the years when the agency has gotten reports of derelict nets in the river. He said he and other gill netters are willing to go pick them up.

“If there are a bunch of ghost nets floating around the river, I’d like to know about them,” he said.

He said gill netters have drift rights in certain stretches of the Columbia, where they will clear logs and debris off the bottom of the river to avoid snagging their nets. It’s possible for a gill netter to lose part of a net in the river, he said, but it’s not common.

I also called the Oregon Department of Fish and Wildlife to see whether the agency keeps any data on the number of birds or other wildlife that are caught and killed in gill nets.

Columbia River fisheries manager John North offered two sets of data that tally bird impacts from gill nets. One is an environmental assessment that was done when marbled murrelets were added to the Endangered Species List. Bird encounters were documented during the winter gill net fishery only from 1991 to 1993.

In those three years, researchers found there was one bird entangled for every 149 gill net set in the lower zone of the river from the mouth of the river to Tongue Point. (A net set is each time a gill netter extends a net across the river. That happens numerous times within each fishery opening. The opening I attended last night lasted 12 hours, and the fishermen set his net about once every hour.) In the next zone upriver, there was one bird entangled for every 213 net sets.

The research found 46 percent of the birds that got entangled were released alive, and that 98 percent of all the net sets had no sea bird entanglements. The National Oceanic and Atmospheric Administration concluded that gill nets were not likely to jeopardize the survival of marbled murrelets in part because there are so few of those seabirds in the river, but also because gill nets don’t encounter birds very often.

North noted another data set that offers a gauge on gill net fisheries from late spring to early summer.

ODFW has worked with a couple gill net boats to tag white sturgeon on the river since 2000. The agency workers on board the gill net boats documented the bycatch as part of that program. Over 13 years of the program, the data shows the boats had one bird encounter in 1,303 net sets. That’s .0076 birds per net set.

North said ODFW doesn’t have any data on the impacts sport fishing gear has on wildlife.

What do you think of those numbers? They don’t account for impacts from ghost nets, but they do give you an idea of how many birds are impacted by gill net fishing.

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