The Fish Trap Project

A Wild Fish Recovery & Community Revitalization Project

In salmon fisheries throughout the Pacific coast, far too often threatened and endangered salmon and steelhead are harvested or die needlessly due to the limitations of today’s conventional fishing methods. This harm, known as bycatch mortality, undermines salmon recovery efforts, further reduces available prey for starving Southern Resident orcas, and constrains indigenous and commercial fisheries.

Searching for a solution to this dilemma, Wild Fish Conservancy began evaluating fish traps in 2016 to determine if this ancient fishing technique, used for thousands of years by indigenous communities for sustainable harvest, could be revitalized once again as an alternative commercial fishing method capable of aiding, not harming, the recovery of wild salmon and steelhead and providing new opportunities for coastal communities and their economies.

What is a fish trap?

A fish trap (also called a pound net) is a low-carbon commercial fishing strategy with potential for efficient harvest of targeted stocks and significant reductions in bycatch mortality of threatened and endangered populations.

How do modern fish traps work?

When migrating upstream, salmon and steelhead first encounter the ‘lead’- a long line of nets supported by untreated pilings that extend from the high-water mark down to the riverbed and are positioned perpendicular to shore. Searching for a route upstream, the fish swim freely into the ‘heart’, a large chamber that passively collects fish and funnels them into progressively smaller chambers until they reach the final chamber called the 'livewell'.

This final compartment, pictured above, has dimensions appropriate for operators to sort the catch for harvest or passive release with little to no air exposure and handling. Salmon and steelhead remain free-swimming the entire time they are within a fish trap and mesh dimensions of nets are selected to minimize or prevent entanglement altogether (in contrast with conventional commercial fishing gears which entangle the teeth and/or gills of all captured fishes, resulting in high rates of bycatch mortality).


Watch the video below to learn more about how fish traps work.

The Passive Capture Technique

With each year of research, our biologists continue to improve the fish trap’s design with the goal of further reducing the gear's impact on wild fish survival. Between 2019 and 2021, Wild Fish Conservancy tested an improved fish trap design using a ‘passive capture technique’ engineered to eliminate major factors associated with mortality in conventional fisheries, including exposure to air, overcrowding, human-handling, and contact with nets.

This revolutionary design allows salmon and steelhead that enter the fish trap to swim freely through a maze of nets until they reach a final chamber. The chamber is affixed with underwater cameras that allow the operator to identify the fish by species or origin (hatchery vs. wild) completely submerged and without handling. From here, targeted species can be selectively removed for harvest and threatened and endangered fish are released by opening a door in the chamber. Our published research demonstrated there was no measurable effect on the survival of fish released using this passive capture technique.

THE FISH TRAP
JOURNAL

Wild Fish Conservancy's virtual field journal dedicated to sharing updates, photos, and stories straight from the deck of our fish trap projects.

Zero Bycatch Mortality

Fish traps release threatened and endangered salmon and steelhead unharmed. Our published research measuring the impact of fish traps on wild salmon and steelhead survival over space and time has shown fish traps can release fish with no measurable effect, or nearly 100% survival post-release.

helps wild fish recover

This selective fishing method allows harvestable healthy and hatchery runs to be selectively harvested, while threatened and endangered wild stocks are passively released unharmed to continue upriver to spawning grounds. 

In systems like the Columbia River with robust hatchery stocks, fish traps can further aid recovery efforts by harvesting hatchery-origin fish produced for harvest, thereby preventing them from reaching spawning grounds where they threaten the genetic fitness of wild fish and compete for resources

research and monitoring

The passive and low-impact nature of fish traps makes them excellent research stations and noninvasive tools to monitor run timing, run size, stock- composition, survival, fish behavior, genetics, PIT tags, and CWT’s.

Chinook & Orca Recovery

Unlike ocean fisheries which compete with or harvest Chinook before killer whales have a chance to feed, fish traps harvest in rivers where mature salmon and steelhead return and after the whales have fed. Reducing the number of Chinook harvested and incidentally killed in commercial salmon fisheries is widely recognized as one of the most critical steps to recovering threatened and endangered Chinook and Southern Resident killer whales.

Good for Fishers

Preserving Northwest Fisheries

By providing fishers a method to harvest with nearly zero impacts to threatened and endangered stocks, commercial fishers can fish healthy wild and hatchery stocks longer and more consistently. Most importantly, fishers can help preserve and sustain their local fisheries for future generations.

Sustainable Marketing

While many seafood products claim to be ‘sustainable’, this fishing method is tested and proven with published research to support. Fish traps can achieve sustainability certifications that lead to higher prices in a market that increasingly values a highly sustainable product, rewarding fishers transitioning to sustainable, selective fishing techniques.

High Quality

Fish traps allow fish to be passively harvested with extremely minimal handling, air exposure, and virtually no entanglement, resulting in minimal stress on the fish and a higher-quality salmon product relative to other gears.

Orca-Safe

In addition to sustainability certifications, fish harvested from fish traps in river systems may be certified or marketed with supporting data as ‘orca safe’ – further driving up the marketable price.

Since 2016, Wild Fish Conservancy’s research represents the only peer-reviewed and published science for alternative commercial gears in the lower Columbia River Basin. The results of this effort have demonstrated the unprecedented ability of contemporary fish traps to reduce or eliminate bycatch mortality of wild salmon and steelhead in commercial fisheries. This published research is now guiding resource managers and policy makers as they work to implement alternative gear fisheries on the lower Columbia River and inspiring adoption of this model at a coastwide level.

Reports & Publications

data sharing

All fish trap research data are publicly available in machine-readable format (excel.csv) below. The Washington Department of Fish and Wildlife has data available for commercial test fisheries from 2018-2020 at the following link.

Research Projects

2016-2017 Research

Lower columbia river, cathlamet, wa

To develop an innovative and effective fishing technology for the reduction of bycatch and hatchery impacts to ESA-listed salmonids and benefit of U.S fisheries, WFC designed, constructed, and monitored the performance of a modified fish trap in the lower Columbia River from 2016-2017 with local commercial fisherman Jon Blair Peterson. Specifically, objectives were to determine the effectiveness of the gear in capturing hatchery-origin Chinook and coho salmon and reducing post-release and cumulative mortality of wild fall Chinook salmon and summer steelhead trout relative to the performance of previously tested commercial gears in the lower Columbia River. Environmental and biological covariates, CPUE, capture conditions, bycatch, immediate survival, and post-release survival of fish were assessed. Similar to previous alternative gear tests, this study intended to achieve three major goals:

  1. Test and refine deployment and operation of a pound net trap under modern conditions of the Columbia River;
  2. Determine effectiveness of the harvest method in capturing salmon relative to previously tested alternative gears. Directly estimate species-specific catch-per-unit-effort (CPUE) and CPUE covariates;
  3. Evaluate the ability of a pound net trap to protect non-target species through identification of capture and release conditions, immediate survival, and post-release survival of fall Chinook salmon and summer steelhead trout.
 

Assessing CPUE from the experimental trap and employing the Cormack (1964)-Jolly (1965)-Seber (1965) method for estimation of survival through paired mark-release-recapture, this study investigated the effectiveness of the alternative gear in capturing targeted stocks with improved survivorship of released fishes relative to previously tested commercial gears. Providing precise and unbiased estimates of cumulative survival to fisheries managers may enable implementation of low-impact stock-selective harvest and/or research tools for the rejuvenation of working waterfronts and the reduction of bycatch and hatchery impacts to wild salmonids.

This project received funding under award #NA17NMF4720255 from NOAA Fisheries Service, in cooperation with the Bycatch Reduction Engineering Program. The project was also funded through the Washington Coastal Restoration Initiative and Patagonia Provisions. The statements, findings, conclusions, and recommendations within the report and publication are those of the authors and do not necessarily reflect the views of the funders.

2018 Research

LOWER COLUMBIA RIVER, CATHLAMET, WA

A commercial trap fishery was established in the lower Columbia River for the first time in over 83 years by the Washington Department of Fish and Wildlife (WDFW) in collaboration with WFC, local commercial fishermen, fish processors, and fish buyers to evaluate the feasibility of the gear in a commercial setting for mark-selective harvest. Specifically, objectives of the test fishery were to determine the economic potential of a mark-selective commercial trap fishery and estimate ecological impacts. Total harvest, revenue, bycatch, CPUE, and immediate survival were assessed in lower Columbia River late-summer and fall fisheries from August through October 2018. The test fishery was established to achieve the following goals:

  1. Evaluate the economic performance of the trap fishery – measure costs, CPUE, fish prices received, total revenue, and projected future added-value;

  2. Evaluate ecological impacts of the trap fishery – further assess immediate survival of captured and released fishes in a commercial setting, estimate total post-release mortality to wild salmonid stocks, and determine bycatch to target species catch ratios;

  3. Investigate use of value-added practices – capture fish passively, minimize air-exposure, minimize handling, live-bleed catch, utilize immersion ice baths, and process locally;

  4. Identify successes and failures of the fall 2018 test fishery and determine next steps.
 

Evaluating revenue generated and estimated wild salmonid fishery mortalities, we compared results from the experimental trap fishery to that of the conventional lower Columbia River mainstem gillnet fishery. Ultimately, this information can be used by fishermen and resource managers to determine the feasibility of mark-selective salmon trap fisheries and the potential benefits of transition to alternative commercial fishing strategies.

This project was funded by the Washington Department of Fish and Wildlife, Oregon Department of Fish and Wildlife, and Wild Salmon Center. The statements, findings, conclusions, and recommendations within the report are those of Wild Fish Conservancy and do not necessarily reflect the views of the funders.

2019 Research, Spring & Summer

LOWER COLUMBIA RIVEr, CATHLAMET, WA

WFC constructed and monitored the performance of an experimental fish trap in the lower Columbia River during the spring and early-summer of 2019 with a modified passive spiller design. Specifically, objectives were to determine the effectiveness of the gear in capturing targeted salmonid and shad stocks for harvest and research while reducing mortality of released fishes relative to the performance of previously tested commercial gears in the lower Columbia River. Environmental covariates, CPUE, capture conditions, bycatch, immediate survival, and post-release survival were assessed. Similar to previous alternative gear tests, this study intended to achieve three major goals:

  1. Test and refine deployment/operation of a pound net trap under modern conditions of the Columbia River and a host of varying seasonal environmental and ecological conditions;

  2. Determine effectiveness of the harvest method in capturing shad, sockeye, spring Chinook, and summer Chinook salmon. Directly estimate species-specific catch-per-unit-effort (CPUE) and CPUE covariates;

  3. Evaluate the ability of a trap to release bycatch and other fishes unharmed during commercial harvest or research operations through identification of immediate and post-release survival of spring/summer Chinook salmon and sockeye salmon.

Assessing CPUE from the experimental trap and employing the Cormack (1964)-Jolly (1965)-Seber (1965) method for estimation of survival through paired mark-release-recapture, this study investigated the effectiveness of the alternative gear in capturing targeted stocks with improved survivorship of released fishes relative to previously tested commercial gears. Providing precise and unbiased estimates of cumulative survival to fisheries managers may enable implementation of low-impact stock-selective harvest and/or research tools for the rejuvenation of working waterfronts and the reduction of bycatch and hatchery impacts to wild salmonids.

This project received funding under continuation of award #NA17NMF4720255 from NOAA Fisheries Service, in cooperation with the Bycatch Reduction Engineering Program. The statements, findings, conclusions, and recommendations within the report are those of the authors and do not necessarily reflect the views of the funders.

2019-2020 Research, Late Summer & Fall

LOWER COLUMBIA RIVEr, CATHLAMET, WA

WFC, Washington Department of Fish and Wildlife (WDFW), and partners conducted a fisheries research, development, promotion, and marketing project to build the foundation for sustainably certified trap fisheries utilizing stock-selective harvest techniques and best business practices in the lower Columbia Sub-basin (Wahkiakum County, WA). Operating a modified fish trap from August through November 2019, the project had the following action plans:

  1. Evaluate a Commercial Trap Fishery: Identify successes and failures of bringing hatchery salmon resources to market for the first time with a new commercial fishing technology.

  2. Perform Research: Monitor catch-composition, immediate bycatch mortality, and post-release bycatch mortality; identify and test engineering modifications to improve gear efficiency and sustainability to meet conservation and management goals.

  3. Develop and Implement Value-Added/Direct Marketing Practices: Form a steering group to ensure use of best practices in harvesting, icing, processing, and marketing to maximize customer base and pricing for sustainably harvested fish.

  4. Initiate Sustainable Market Certification Processes: Initiate the certification process for fish trap fisheries with Monterey Bay Aquarium’s Seafood Watch (MBASW) to increase product profile, customer base, and future fish value in the marketplace.

  5. Plan for the Future: Develop proposed gear regulations, identify potential trap sites, streamline the permitting process, raise awareness of alternative harvest tools, and identify stakeholder mitigation options and appropriate economic incentives to facilitate an alternative gear transition in the lower Columbia River through an Emerging Commercial Fishery designation.
 

Through the completion of these research and marketing experiments, WFC and partners have increased the availability of information necessary for WDFW to potentially implement fish traps as a legal alternative fishing gear in lower Columbia River commercial fisheries. Ultimately, the goal of this project was to inform the implementation process for alternative gears to increase sustainable harvest opportunities for hatchery-origin salmon while addressing both harvest and hatchery factors known to limit recovery of ESA-listed wild salmonids.

This project received funding under award #NA19NMF4270028 from NOAA Fisheries Service, in cooperation with the Saltonstall-Kennedy Grant Program.

2021 Research

LOWER COLUMBIA RIVER, clifton, or

Building upon prior salmon trap research for the reduction of bycatch impacts to ESA-listed species and benefit of U.S fisheries, WFC and partners conducted the next steps necessary for fish trap testing and implementation. Specifically, objectives were to quantitatively evaluate the effectiveness of a substantially modified passive fish trap design in capturing hatchery salmon and reducing bycatch mortality of ESA-listed salmonids in a currently untested location within the lower Columbia River, OR. Similar to prior evaluations, this study had three major goals: 

  1. Permit, engineer, construct, and refine deployment/operation of a substantially modified fish trap in a new location within the lower Columbia River Basin, OR.

  2. Evaluate the effectiveness of the harvest method for selective capture of hatchery-origin salmonids relative to previously tested gears. Determine species-specific catch and bycatch encounters.

  3. Determine the ability of the modified passive capture design to effectively release non-target stocks through estimation of immediate and post-release survival of Chinook salmon, coho salmon, and steelhead.

Employing a paired Cormack (1964)-Jolly (1965)-Seber (1965) methodology to estimate post-release survival for Chinook and steelhead and a net pen holding methodology to investigate post-release survival of coho, this study provided estimates of catch composition and bycatch mortality for a modified salmon trap. Results will help resource management agencies evaluate the utility of using alternative commercial gear in efforts to reduce bycatch and hatchery impacts for the recovery of ESA-listed salmonids and coastal fishing economies.

This project received funding under award #NA19NMF4720230 from NOAA Fisheries Service, in cooperation with the Bycatch Reduction Engineering Program. Funding was also provided by WDFW, ODFW, the Raynier Institute & Foundation, and Patagonia.

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