Arctic Science Journeys
Radio Script
1997

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Nets That Let Fish Go
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STORY: Fishermen off the coast of Alaska have the kind of problem that fishermen elsewhere can only dream about. They catch lots of fish, especially pollock, a fish that's used to make things like imitation crab and fish sticks. But along with the fish they keep, Alaska fishermen throw away millions of pollock too small to be processed or sold.

Dan Erickson is a fisheries scientist at the University of Washington who says the waste is a serious environmental issue.

ERICKSON: "Less than 10 percent of the catch is undersize pollock that isn't being used. The problem is that it's such a high volume fishery, so that it results in many thousands of metric tons of pollock that are discarded and not used."

Erickson and colleagues Chris Bublitz from the University of Alaska Fairbanks and Ellen Pikitch from the Wildlife Conservation Society in New York have a solution. They recently tested an innovative net design that lets small fish escape. The net is conventional in most respects, except that researchers replaced sections along the top of the net with a square-mesh webbing big enough to let undersize fish swim through. The results, captured on videotape, surprised researchers including Dan Erickson.

ERICKSON: "What we learned, and we didn't know this before we installed a video camera, is that pollock--as the net is overtaking them--aggressively swim up toward the meshes on the top panel. And the small fish, by swimming up that way, are actively getting out of the net. You see the noses of the larger fish bumping along the tops of the net, but they can't get out because they're too large."

Ellen Pikitch says the video shows that small pollock were able to escape through the square-mesh panels even when the net was filled with fish. She says the video proves the net design works, but more important, she believes the video will convince fishermen to modify their own nets to let undersize fish escape.

PIKITCH: "Not only are these pictures really good for figuring out how to modify the gear and whether or not it's working, but it's really good at convincing people that it really works. The fisherman whose boat we were out on went out and bought the square mesh panel for his own fishing that season. He saw the net coming up clean and saw the fish escaping in the video and that convinced him."

Chris Bublitz at the University of Alaska Fairbanks says that before they began using video cameras, they conducted extensive tests and made numerous comparisons just to infer how well their designs worked. Now, he says, technology holds great promise for testing improvements quickly.

BUBLITZ: As new developments in video and acoustics come out, we may be able to go in different directions. There's been some work done for example that uses laser light to light up the mouth of the trawl so the camera can go deeper and work in dark conditions. These have worked to some degree. But they're in their infancy right now and it's going to be a gradual process in which we utilize new techniques. As these new techniques are perfected we get more and better information."

Such improvements likely will be welcomed by industry as well, since new laws that require fishermen to process small fish will make it more expensive than finding ways to avoid catching them in the first place.

OUTRO: For Arctic Science Journeys Radio, this is Robert Hannon reporting from Fairbanks, Alaska.