Commercial fishermen respond that the timing of gillnetting is set to minimize impacts on wild fish, and that sports anglers kill them, too.

Though sports anglers sometimes complain that gillnetters get too high a percentage of the available salmon and sturgeon, Stachon said his group isn't trying to get rid of commercial fishing on the Columbia altogether. "We want a healthy commercial industry, but we want to protect wild fish," he said.

However, under I-21, the commercials would have to switch to seines in Oregon waters instead of gillnets.

Since 2009, the Washington Department of Fish and Wildlife has been researching the use of other types of commercial fishing gear on the Columbia, such as purse seines. With such seines, wild fish can be removed in the water so there's a lower mortality rate.

Kytr said several more years of research are needed before the federal National Marine Fisheries Service could approve the use of seines on the Columbia.

Even if seining were eventually permitted on the Columbia, most gillnet boats can't be converted to seining, Kytr said.

"Industries and the ways we do things evolve all the time," Stachon said. "In the long term, we can make this transition."