Fish traps have been outlawed in the Pacific Northwest for decades, but researchers plan to test an experimental trap in the Columbia River in hopes that it will be safer for wild fish than traditional fishing methods.
Adrian Tuohy, a biologist and project manager for the Wild Fish Conservancy, said the proposed fish trap, also called a pound net, would be put in the Oregon side of the river so biologists can monitor how many fish are in the river and how many wild fish survive after being released.
“We’ll be looking at survival of bycatch so that researchers know the impact on fish we tag and have good research and results,” Tuohy said.
Bycatch is a term for other fish and marine animals that are accidentally caught while fishing for a different species. In this case, the researchers want to make sure endangered and threatened populations of wild salmon are released from the nets safely.
“Gillnets and other conventional harvest techniques don’t really release bycatch very well so whatever you catch you often kill,” Tuohy said. “So when researchers are trying to collect data we want to have the lowest-impact tool so we can release the fish unharmed.”
Fish traps were banned in Washington state in the 1930s and in Oregon in the 1940s. It was a time when corporations in Washington were using fish traps and overharvesting, causing salmon populations to plummet.
“They were very efficient for catching fish and the quality was greater because it didn’t harm fish, but they were not being selective,” Tuohy said. “Everybody started pointing their fingers at fish traps, so they were banned.”
However, fisheries are heavily regulated now compared to back then.
Inside the trap, fish swim through a maze of walls and compartments to an area where they can be identified and tagged. The researchers or fishermen can open a compartment and let the bycatch swim free.
Washington has started the process to legalize fish traps. Oregon has already changed its regulations on fish traps, but hasn’t yet put them into practice.
But before making any conclusions about this net, there are many factors to consider, according to John North, Columbia River fisheries manager at the Oregon Department of Fish and Wildlife.
“It all sounds good, but when you get out in practice and implement it, people have run into challenges,” North said.
He listed factors researchers need to think about, such as the mortality rate of the released fish, the types of fish caught and released, the amount of fish and the cost of operating this kind of gear.
The mortality rate of released fish is not enough information in itself, North added, as it needs to be paired with the total numbers of fish. If only 10 fish are released but they all die, that 100% mortality rate shouldn’t be compared to a 10% mortality rate in a case when 100 out of 1,000 fish die.
North said testing these nets in multiple locations will help researchers find out if they’re more or less effective at different sites.
“This new site will certainly give us new information,” North said.
In Oregon, the traps will be used for research. Separately in Washington, the Wild Fish Conservancy has already been testing alternative gear to be used in commercial fisheries.
Derek Orner, the national bycatch program coordinator with NOAA Fisheries, said the project in Washington has been successful so far.
“Between the two programs we’re looking to increase the harvest of hatchery fish while releasing the majority of the wild population, while providing hatchery fish to the restaurant chain,” Orner said.
Orner added the pound nets are new for commercial fishermen, as they haven’t been allowed in the Columbia River for so many decades. North said some fishermen are reluctant to change their methods, which are already regulated.
But to Tuohy, using this type of trap is worth the change.
“There’s a lot of fish populations that aren’t doing well,” Tuohy said. “If you don’t have another tool, you’re almost out of business because the damage you cause to those threatened and endangered species will shut you down.”
Tuohy said the experimental net is planned to go on the Oregon side of the Columbia next year.
“This is a research project and I sincerely hope people understand that and don’t jump to conclusions that while we’re doing research we’re harvesting fish, because that simply isn’t true,” Tuohy said.