Session Chair: Carlie Herring, National Oceanic and Atmospheric Administration, Marine Debris Program
This session will focus on actionable guidance or findings from research to prevent gear loss and to disable lost gear in order to reduce target species mortality and habitat impacts.
Lost or discarded fishing gear that is no longer under a fisherman’s control becomes known as
derelict fishing gear (DFG), and it can continue to trap and kill fish, crustaceans, marine mammals, sea turtles, and seabirds. The most common types of DFG to ghost fish are gillnets and crab pots/traps. Ghost fishing can impose a variety of harmful impacts, including: the ability to kill target and non-target organisms, including endangered and protected species; causing damage to underwater habitats such as coral reefs and benthic fauna; and contributing to marine pollution.
Derelict fishing gear (DFG) can continue to confine and entangle both target and bycatch species with implications for the overall status of these populations. DFG resting on top of or becoming entangled with habitat-forming species leads to physical abrasion and breakage and during high wind events, DFG can move great distances, creating large areas of impact. Although the contribution of abandoned, lost, or otherwise discarded fishing gear to marine debris has long been recognized worldwide, quantitative data are sparse for many regions.
This technical session will highlight research that seeks to prevent gear loss and to disable lost gear. Speakers in this session will highlight actionable guidance or findings from research that could be implemented more broadly through pilot studies or regulatory changes.
Topics of interest include: gear alternatives; gear modifications to prevent loss; gear modifications to disable lost gear; best practices to reduce loss; best practices for engaging with fishermen; rate of loss studies; derelict gear density studies; target species mortality in derelict gear; habitat impacts from derelict gear
While removal efforts can be discussed, speakers will be asked to explore implementable results from their projects, rather than just the removal methods and amount of derelict gear removed.
Using ecosystem services to evaluate environmental impacts from ALDFG
presenting: Dina Margrethe Aspen (Norwegian University of Science and Technology, Norway); authors: Dina Margrethe Aspen (Norwegian University of Science and Technology, Norway), Laura Brodbeck (Kjeller Innovasjon AS), Paritosh Deschpande (Norwegian University of Science and Technology)
In order to understand the potentially harmful effects from abandoned, lost or otherwise discarded fishing gear (ALDFG) an environmental impact assessment approach is necessary. As there currently are no harmonized methodologies for which to describe and communicate such impacts, this study employs the ecosystem services theory to evaluate adverse impacts from ALDFG on marine and coastal ecosystems. The goal of the study is two-fold: Firstly to structure existing literature reporting on adverse environmental effects using a single, unified framework, and secondly to evaluate the feasibility of this approach as a common platform for monitoring and communicating impacts from ALDFG. For this purpose, 48 peer-reviewed articles and grey literature has been structured and analyzed according to impacts on human activities through supporting, provisioning, regulating, and cultural services. A taxonomy of impact sub-categories is developed based on the literature and mapped on to ecosystem services categories. The review shows that the approach provides a meaningful interpretation of adverse effects of ALDFG on marine and coastal ecosystems in a qualitative manner. Further development of indicators associated with ecosystem service categories is recommended to help specify the intensity of adverse impacts.
Derelict Gillnets in the Salish Sea: Causes of Gillnet Loss, Extent of Accumulation and Development of a Predictive Transboundary Model
presenting: Kyle Antonelis (Natural Resources Consultants, Inc., United States); authors: Kyle Antonelis (Natural Resources Consultants, Inc., United States)
From 2002 through the end of 2012, a total of 4,358 derelict nets were removed from the Washington waters of the Salish Sea (WASS), 95% of which were gillnets. Forty-five percent of these gillnets were removed from low to high relief rocky substrate. The causes and rates of gillnet loss from the WASS commercial salmon fishery were investigated through interviews with fishers and industry professionals and analysis of historical fishing effort. Major causes of gillnet loss included lack of experience, operator error, equipment malfunction, overcrowding of fishing grounds, mismatch of net depth with ocean depth, and more. The findings suggest that gillnet loss is currently much less frequent than in previous decades characterized by heavy fishing effort (i.e., 1970s–1980s). Analysis of net removal records identified patterns of association between net fishing depths and depths at which derelict nets are found. Spatial analysis and ArcGIS were used to produce a simple model capable of identifying areas of high, moderate and low probability of derelict gillnet occurrence. This model was applied to the British Columbia waters of the Salish Sea (BCSS) where an organized derelict fishing gear removal program has yet been implemented. This study refines previous estimates of derelict gillnet quantities in the WASS, identifies the major causes for derelict gillnet loss, and produces an exportable model that can be used to assist the design and implementation of derelict fishing gear surveys and removal efforts in British Columbia and beyond. This model was used successfully to design continued derelict net survey plans in the WASS since 2013. Additionally, recent derelict net surveys and removals in specific locations of the BCSS have provided valuable information to test hypotheses developed here and model accuracy.
Understanding causes of gear loss provides a sound basis for fisheries management
presenting: Kelsey Richardson (University of Tasmania, Australia); authors: Kelsey Richardson (University of Tasmania, Australia), Riki Gunn (), Chris Wilcox (Commonwealth Scientific and Industrial Research Organisation (CSIRO)), Britta Denise Hardesty (Commonwealth Scientific and Industrial Research Organisation (CSIRO))
Ghost nets are an acute problem in Australia’s Gulf of Carpentaria, with most nets originating from South-east Asian fishing vessels outside Australia’s Exclusive Economic Zone. A range of stakeholders in the Gulf including the Australian government, Indigenous communities, non-profit organisations and researchers have been working since the 1990s to collect data about these nets and remove them from the coastlines. While the work of these stakeholders has been invaluable in informing and mitigating impacts of the ghost net issue, long-term, sustainable solutions require an understanding of the causes and drivers of net loss that can inform solutions designed to reduce gear loss at its source.
To understand the drivers of gear loss and identify tractable solutions to this transboundary problem, we asked Australian and Indonesian fishers active in trawl, gill net and purse seine fisheries why, when and in what circumstances and conditions they are likely to lose gear. Using data from these interviews we address four questions: 1) what are the primary causes of gear loss in the region, 2) what are the underlying pressures and drivers that result in gear loss events, 3) what ongoing and past initiatives have been undertaken to address these pressures and drivers, and 4) what additional measures can be undertaken to further reduce gear loss. Our overall goal was to develop a fault tree tool which provides guidance for interventions and improvements in regional fisheries management to reduce the significant pressures that result from overcrowding, overcapacity and illegal, unreported and unregulated Fishing (IUU).
Grappling the Invisible: A Derelict Crab Pot Removal Pilot Study in the Delaware Bay- Lessons Learned
presenting: Nicole Rodi (Department of Natural Resources and Environmental Control, Delaware Coastal Programs, United States); authors: Nicole Rodi (Department of Natural Resources and Environmental Control, Delaware Coastal Programs, United States), Kari St.Laurent (Department of Natural Resources and Environmental Control, Delaware Coastal Programs)
The Mid-Atlantic region has had great success with watermen-led removal of derelict crab pots in shallow coastal bays. The success of Stockton University (SU) in the back bays of New Jersey, and of Virginia Institute of Marine Science in the Chesapeake Bay, inspired the Delaware Department of Natural Resources and Environmental Control, Delaware Coastal Programs (DCP), to expand on these efforts to provide similar data and consistent stewardship across the region. DCP is working with the commercial crabbing industry in the Delaware Bay to improve habitat and prioritize loss reduction. The DCP crab pot removal pilot project has had various challenges that came with working in a very different estuarine system compared to Chesapeake Bay and the New Jersey back bays; sharing knowledge about lessons learned and identifying important factors to consider when starting a project will help guide others interested in pursuing a derelict fishing gear removal project. The greatest challenge of the project has been the use of a more cost effective but less accurate Huminbird side scan unit for the primary identification of crab pots. In the coming months, DCP hopes to work in collaboration with SU to identify crab pots in the Delaware Bay using the Klein 3900, a more accurate, yet expensive, side scan. The DCP will be exploring how this system might compare in accuracy with the more affordable Humminbird side scan unit.
Using Smart Buoys to Detect and Locate Lost Gear
presenting: Kortney Opshaug (Blue Ocean Gear LLC, United States); authors: Kortney Opshaug (Blue Ocean Gear LLC, United States)
Derelict crab and lobster traps have a devastating financial and environmental impact, costing fishermen thousands of dollars in replacement gear, while continuing to ghost fish and entangle marine mammals at rates high enough to impact the sustainability of the fisheries. Being able to retrieve these traps as soon as possible after they are lost would reduce the amount of damage to the ocean ecosystem. The research presented here by describes a Smart Buoy developed by Blue Ocean Gear as part of the National Fish and Wildlife Foundation’s Fishing For Energy Program with funding from NOAA’s Marine Debris Program. The Smart Buoy can detect when gear starts to wander outside its normal range, which can indicate impending loss of the gear, and communicates alerts back to the fishermen onshore along with current location. This facilitates the recovery of gear by identifying where immediate retrieval efforts should be focused. The concept has been implemented and tested in Dungeness Crab fisheries off the coast of Northern California. Results from open-water testing of the gear will be presented, and potential broader applications discussed.
Estimating the Ecological Benefits of Techniques that Reduce Ghost Fishing
presenting: Courtney Arthur (Industrial Economics, Inc. (IEc), United States); authors: Courtney Arthur (Industrial Economics, Inc. (IEc), United States), Scott Friedman (Industrial Economics, Inc. (IEc))
Ghost fishing in derelict fishing traps kills target and non-target species and, though research and removal efforts have targeted derelict traps in many coastal areas, ghost fishing remains a substantial problem across the United States. From a fisheries conservation standpoint, techniques that reduce ghost fishing in trap gear may help restore a number of marine and estuarine fish and shellfish species. Some of these species are important to commercial and recreational fisheries, and have economic and cultural value for many different groups. Techniques to reduce ghost fishing may include trap removal or trap construction strategies to limit ghost fishing if a trap is abandoned, lost, or otherwise discarded. Utilizing a model developed for the Gulf of Mexico, we will evaluate the ecological benefits to fish and shellfish resources due to removal of derelict fishing traps and advances in trap construction (e.g., installation of degradable escape panels). This model will estimate benefits in metrics of the number and biomass of fish and shellfish not killed in derelict fishing traps. We will apply this model to multiple affected coastal locations across the United States, provide an assessment and comparison of the benefits per location, and discuss how the model may be applied to generate information for resource managers considering implementation of derelict trap removal programs and/or initiatives to encourage installation of degradable components.