Columbia River fisheries: Myths and facts

Endangered Species Act (ESA) requirements are the first consideration for any salmon or steelhead fishery on the Columbia River. Several Columbia River stocks are listed under the ESA, such as upper Columbia spring Chinook, Snake River steelhead, and lower Columbia coho, among others, and these stocks can affect fisheries in the river year-round.

The ESA limits the allowed impacts to listed salmon and steelhead. Under ESA considerations, a limited number of listed wild fish can be incidentally impacted by either recreational or commercial anglers while not jeopardizing the survival or recovery of listed runs. Managers also build in additional buffer, developing catch quotas well below maximum allowable ESA limits, to ensure limits aren’t exceeded in the event that fishing pressure or catch rates are higher than expected.

Using run-size data, catch data, and modeling, fishery managers are able to adapt quotas and fishing days to ensure conservation goals are being met and harvest activities remain within the ESA limits. Joint state postseason staff reports on Columbia River fisheries are available online.

A mark-selective fishery is one in which fish that are “marked” – those that have had their adipose fin removed before being released from a hatchery – can be kept, while “unmarked” fish are released. Mark-selective fisheries are used throughout Washington to focus harvest on hatchery fish and allow wild fish to make their way to their home spawning grounds.

The type of fishing gear used in a mark-selective fishery is one of the major factors that influences the mortality rate of unmarked fish caught incidentally and released. Each gear (such as hook-and-line, pound net, drift gillnet, and tangle net) has a “mortality rate” associated with released salmon or steelhead encountered by that gear. The mortality rate represents the likelihood that a fish that encounters a type of gear and is released, will later die as a result of encountering that gear. Both encounters and mortalities are considered when calculating ESA impacts -- a fishery with a high encounter rate but low mortality rate can ultimately result in the same number of impacts as a fishery with a low encounter rate but a higher mortality rate.

In the Columbia River, the number of wild fish that can be incidentally killed in fisheries is set by the U.S. v. Oregon Management Agreement. These mortality rates are agreed to by the U.S. v. Oregon Technical Advisory Committee (TAC)for each gear type in use.

Every fishery, whether recreational or commercial, is meant to primarily target one or perhaps a few species depending on location and time. For example, the spring Chinook fishery targets hatchery spring Chinook, at the same time that steelhead and wild Chinook are moving upriver. As a result, some of these “non-target” fish will be inadvertently caught and released, regardless of gear.

Fishery managers monitor catch rates and model these inadvertent encounters in combination with mortality rates to determine if fisheries are meeting or exceeding their allowable impacts. Fisheries are managed in-season to reduce or close fisheries based on the results of this monitoring and evaluation.

All Columbia River salmon and steelhead fisheries are managed with conservation measures in mind – in addition to ESA limitations, managers also evaluate the numbers of fish returning to Columbia River-basin hatcheries and spawning grounds, and adapt fisheries based on that information to ensure conservation goals and broodstock objectives are met. The Technical Advisory Committee monitors and updates run sizes in-season, which in turn inform fishery openings, closures, and modifications as new information becomes available.

Many fisheries are also exclusively mark-selective, meaning all wild fish must be released. This is an important conservation measure, and many anglers and commercial fishers are conscientious of the requirement to responsibly handle fish in a way that reduces mortalities and improves the chances of a fish making it upriver.

Some fishing gear types have seen little modification in the past few decades, but there are a number of measures that fisheries in the Columbia River have taken in an effort to improve the efficiency of fishing gear and reduce mortality rates of Columbia River fish.

For example, barbless hooks have been required for nearly all Columbia River salmon and steelhead hook-and-line fisheries since 2013, which is believed to make it easier for anglers to release wild fish unharmed. In addition, commercial fisheries on the Columbia River have seen progress on the use of alternative gears in the past decade, such as the tangle net, which spends less time “soaking” in the water, reducing stress on non-target species when they become entangled. The use of recovery boxes has also become more common, which allow fish to recover from the stress of being entangled before being released back into the river. Some tangle net fishers also incorporate steelhead excluder panels into their nets.

In-season management is a critical component of all Columbia River fisheries. Fisheries will frequently open, close, or be modified in-season as a result of updated information such as forecasting, fish passage counts at dams (such as Bonneville Dam), creel and catch reporting, and information-sharing between states and tribal co-managers.

Although many fishing gears may not be able to target only hatchery fish when wild and hatchery fish overlap in the same area, fishery managers and fishers can be strategic about when, where and how to use each gear. For example, the mesh size of a drift net can be either larger to allow smaller fish to pass through the mesh, or smaller so as to entangle fish, but not gill them. The latter leads to a lower mortality rate as non-target tangled fish are more likely to be released alive.

Another example comes from deciding what time of year to employ the gear. Tangle nets are only used in the spring to target spring Chinook salmon, when the run size is large enough to support commercial tangle-net fisheries while remaining below the wild spring Chinook salmon impact rates agreed to in the U.S. v Oregon Management Agreement.

The Select Area Fisheries Enhancement (SAFE) areas are another example where gear can be used selectively. Hatchery fish reared for the SAFE program are intended to be caught. Drift gillnets are used in these areas because they allow for a large number of hatchery fish to be caught with minimal numbers of non-target fish encountered and caught due to their location in off-channel areas that wild fish tend not to occupy. 

Tangle nets are small-mesh nets that tangle the target fish instead of catching them by their gills. Tangle nets have lower mortality rates than gillnets when accidentally caught fish are released. In addition to similar “time and place” requirements as those used in gillnet fisheries, tangle nets also have a shorter “soak time” than gillnets, meaning the nets are pulled in more frequently, further reducing potential mortalities by allowing fishers to release non-target fish.

For many years, the primary gear used to fish commercially in the Lower Columbia River was the drift gillnet. Recently there has been interest in working to develop gears capable of removing large numbers of hatchery fish like drift gillnets do, but with lower incidental mortality rates and/or encounter rates on wild fish than drift gillnets.

Over the last decade, the states of Oregon and Washington, along with the Wild Fish Conservancy and the commercial fishing industry, have been investigating the feasibility of other gears such as the tangle net, pound net, beach seine, and purse seine to be as effective and economically viable at catching fish as the drift gill net, but with fewer impacts to wild fish for each harvested fish.

The underlying factor in any fishery involving an ESA-listed species is the number of allowable impacts to that species. That number stays the same regardless of the type of gear being used, whether it’s recreational anglers using rods and reels or commercial vessels deploying gillnets. Hatchery fish are present in much greater abundance than wild, but impacts to wild fish are the limiting factor in many of these fisheries. So even when hatchery fish are still available for harvest, fisheries must be closed or otherwise restricted if impacts are reached.

While hatcheries serve an important role in supplementing fish runs, there is also a conservation challenge tied to balancing the influence of hatchery fish on spawning grounds (a metric known as pHOS; the proportion of hatchery-origin spawners). Harvest – both commercial and recreational – plays a critical role in these conservation objectives by removing large numbers of hatchery fish from the river while allowing wild salmon to continue to the spawning grounds.

Alternative gears are meant to provide exactly what the name implies: “Alternatives” to the traditional gillnet. Gillnets have long served a useful purpose as an economically viable option for commercial harvest, and in the past when runs were more abundant and allowable impacts were higher, were very efficient at aiding conservation by removing large numbers of hatchery fish.

But in recent years, with consistently low run sizes and continued strict ESA conservation measures in place, a need for gear with lower mortality rates has also emerged. These gears are not intended to replace gillnets, but simply to provide the most appropriate tools for commercial fisheries dependent on time, place, and opportunity. Some of these gears may not catch fish as efficiently as a gillnet, or perhaps carry a high capital cost or permitting requirements. Ultimately, development of alternative gear is meant to coincide with a reduction in the size of the Columbia River commercial fleet, allowing managers to more accurately predict commercial effort on a year-to-year basis.