Derelict Gear Research
Research is an important component of the Derelict Fishing Gear Program. Marine biologists document the location, condition, age, and lethality of each piece of derelict gear removed. We also identify and catalog each animal found in nets and pots and note habitat characteristics. Collecting this data documents the impact that derelict gear has on Puget Sound’s marine environment, and also helps us understand which gear types are causing the most damage and where. This feeds into our prioritization process and ensures that we expend effort to tackle the most deadly gear first. The Northwest Straits Initiative manages and maintains a complete database of derelict fishing gear.
We also raise funds to carry out stand-alone research projects to gain a more complete understanding of derelict gear mortality, habitat recovery following removal of gear, the costs and benefits of removing gear, and other information that shapes and guides our program.
Recent research projects
Spatial Distribution and Magnitude of Derelict Shrimp Pots and their Potential Impacts to Rockfish in Puget Sound
K. Antonelis, J. June
Publication Date:
September 20, 2012
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Derelict fishing gear is a potential stressor to ESA listed rockfish species in Puget Sound, but little has been done to quanitify the extent or impacts of derelict shrimp pots. Through analysis of shrimp pot fishing effort, rockfish encounter documentation and areas of known rockfish habitat, locations for sidescan sonar surveys targeting derelict shrimp pots were identified and conducted.
Deepwater Sidescan Sonar and Camera Surveys for Derelict Fishing Nets and Rockfish Habitat
Natural Resources Consultants, Jeff June
Publication date: January 2011
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This study tested the feasibility of employing sidescan sonar surveys to locate derelict nets in deepwater (105-350ft) rockfish habitat, verigy the findings with camera surveys, as assess potential threats to the rockfish population.
Derelict fishing nets in Puget Sound and the Northwest Straits: Patterns and threats to marine fauna
Thomas Good, Jeffrey June, Michael Etnier, Ginny Broadhurst
Publication date: September, 2009
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Derelict fishing gear remains in the marine environment for years, entangling, and killing marine organisms worldwide. Since 2002, hundreds of derelict nets containing over 32,000 marine animals have been recovered from Washington’s inland waters. Analysis of 870 gillnets found many were derelict for years; most were recovered from northern Puget Sound and high-relief rocky habitats and were relatively small, of recent construction, in good condition, stretched open, and in relatively shallow water. Marine organisms documented in recovered gillnets included 31,278 invertebrates, 1036 fishes , 514 birds, and 23 mammals; 56% of invertebrates, 93% of fish, and 100% of birds and mammals were dead when recovered. For all taxa, mortality was generally associated with gillnet effectiveness. Mortality from derelict fishing gear is underestimated at recovery and may be important for species of economic and conservation concern.
Quantifying the impact of derelict fishing gear on the marine fauna of Puget Sound and the Northwest Straits
Thomas Good, Jeff June, Michael Etnier, Ginny Broadhurst
Publication Date: September, 2007
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Derelict fishing gear can remain in the marine environment for years. Unseen and largely unquantified, this marine debris can trap and kill marine organisms. Since 2002, a project removing derelict gillnets from Puget Sound and the Straits of Georgia and Juan de Fuca has documented the capture and mortality of marine taxa. Specimens collected during gear recovery are enumerated and identified to the lowest possible taxon as nets are pulled onboard and/or using osteological characters in the lab. Derelict gillnets captured and/or killed marine invertebrates, marine fishes, marine birds and marine mammals.
Marine species mortality in derelict fishing nets in Puget Sound, WA and the cost/benefits of derelict net removal
Kirsten V.K. Gilardi, Daphne Carlson-Bremer, Jeffrey A. June, Kyle Antonelis, Ginny Broadhurst, Tom Cowan
Publication Date: 2010
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Using data collected from repeated survey dives on derelict gillnets in Puget Sound, the authors estimated the daily catch rate of a given derelict gillnet, and developed a model to predict expected total mortality caused by a given net based on entanglement data collected upon its removal. The authors also generated a cost:benefit ratio for derelict gear removal utilizing known true costs compared to known market values of the resources benefiting from derelict gear removal. For one study net, we calculated 4368 crab entangled during the impact lifetime of the net, at a loss of $19,656 of Dungeness crab to the commercial fishery, compared to $1358 in costs to remove a given gillnet, yielding a cost:benefit ratio of 1:14.5.
Application of Side Scan Sonar for the Detection of Derelict Fishing Gear
Jeffrey June, Abby Faust, Crayton Fenn
Publication Date: 2010
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Until recently, the Northwest Straits Initiative primarily used drop cameras to survey for derelict nets, but these cameras have a narrow survey swath limited by the field of view, light and water clarity. In order to more effectively survey for derelict nets, surveyor Crayton Fenn worked with Marine Sonic Technology, Ltd. to adapt their sonar equipment to the needs of the program. This technical report describes the technique and its success.
Rates of Marine Species Mortality Caused by Derelict Fishing Nets in Puget Sound, Washington
Natural Resources Consultants, Jeff June
Publication Date: May 29, 2008
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During the spring and summer of 2007 the Northwest Straits Initiative and Natural Resources Consultants, Inc., began a derelict net monitoring project in Puget Sound, Washington, to study the rates at which derelict gillnets entangle marine animals and the decomposition processes those animals undertake after entanglement. Results of this study show that animals cycle quickly through derelict nets, decomposing or being consumed by other animals. The number of animals present in a given derelict net at the time it is removed represent only a snapshot of about a week’s worth of mortality. From this research, it is estimated that one net left derelict for 12 years may have killed 5,000 animals, including 1,000 birds. The Northwest Straits Foundation has completed a similar research project to determine mortality rates from derelict crab pots.
Derelict Fishing Gear Priority Ranking Project
Natural Resources Consultants, Jeff June
Publication Date: December 31, 2007
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This report identifies the highest priority areas in Puget Sound for derelict fishing gear removal based on objective criteria developed by experts in the field. It gives an estimate of the total amount of derelict fishing gear accumulations throughout Puget Sound and the costs of removing 80-90 percent of derelict fishing gear from the highest priority areas by 2012 based on estimated total accumulations and known removal costs.
A Cost-Benefit Analysis of Derelict Fishing Gear Removal In Puget Sound, Washington
Natural Resources Consultants, Jeff June
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This report summarizes the costs and benefits of removing derelict crab pots and nets from Puget Sound. Benefits are derived by estimating the lost value of commercial species caught in derelict gear each year. Removing gear as a source of fisheries mortality would provide a positive cost benefit ratio of 1:1.28 for pots/traps and 1:1.27 for derelict nets. Ecosystem and other nonmarket values are not factored into this estimate.
Escape Cord Degradation Rates in Port Townsend, WA
Robyn Redekopp, Wendy Fisher, Morgan Neal, Donald Velasquez, Stephan Frenzl
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This technical report describes research into the rate that different types of escape cord decay in the marine waters of Puget Sound. Escape cord (also called rot cord) is used to secure crab pots and gradually decays over time to release trapped crab should a pot become derelict. Different types of cord decay at different rates and this study was designed to identify those differences to determine guidelines for escape cord use.
Marine Habitat Recovery of Five Derelict Gear Sites in Puget Sound
Natural Resources Consultants, Jeff June and Kyle Antonelis
Publication Date: Febuary 11, 2009
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Derelict nets and pots scour, smother, and scrape across eelgrass beds, kelp forests, and rocky reefs. Damage to habitat can be extensive and habitat restoration is one of the many benefits of derelict gear removal. The Northwest Straits Foundation is researching the rate at which marine habitat recovers following removal of derelict gear. After a year of monitoring both net and crab pot removal sites, divers have observed near total habitat recovery.
Mortality of Dungeness crabs (Cancer magister) due to lost traps and the cost benefit of removal in Washington State waters of the Salish Sea
K. Antonelis, D. Huppert, D. Velasquez, J. June
Publication Date: May 6, 2010
Download from North American Journal of Fisheries Management
The Northwest Straits Initiative derelict fishing gear project assessed the impact of derelict crab traps by collecting scientific data on both the trap condition as well as the number of live and dead crabs and other animals caught by the derelict traps. The objectives of the study were to estimate crab catch and mortality rates of Dungeness crabs due to lost traps, estimate potential total annual crab volume and exvessel value of losses to fisheries and compare the value of crabs saved with the cost of removal in a cost benefit analyses.
Northwest Straits Marine Conservation Initiative, authorized by Congress, is nationally recognized as an innovative approach to bring sound science and an ecosystem perspective together with citizen energy and entrepreneurship. The Northwest Straits Foundation is a non-profit organization established to support the scientific, restoration, and education projects and programs of the Northwest Straits Marine Conservation Initiative.