Download or read book Observing Fish Behavior and Evaluating Gear Design to Reduce Bycatch of Small Mesh Trawl Fisheries in New England written by Shannon Michael Bayse and published by . This book was released on 2015 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bycatch reduction devices (BRDs) are employed in trawls to reduce the capture of unwanted species. Evaluation of these devices is critical to determine how well bycatch is reduced, and to assure that target species catch is retained at a commercial level. This dissertation evaluated new BRD design for the silver hake (Merluccius bilinearis) and longfin inshore squid (Doryteuthis pealeii) fisheries. Due to the small size of the target species, both of these fisheries require small mesh condends, 76 mm or less. Bycatch concerns are inherently greater for small mesh fisheries due to the potential of retaining most fish that enter the trawl. Evaluation of BRDs was conducted by both video analysis and catch comparison techniques to determine the effectiveness of the new trawl design. At the time of this work, BRDs mandated in the Maine silver hake fishery had proved ineffective, warranting a new BRD design. An experimental trawl with a large mesh belly window and Nordmøre-style grid caught a commercial quantity of silver hake and reduced the catch of regulated groundfish species (p
Download or read book Fish Behavior and Its Application in Species Selective Trawl Nets in the Southern New England Large Mesh Groundfish Fishery written by Natalie Frances Jones and published by . This book was released on 2015 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trawl nets have been a fixture in commercial fishing since the late 1800s. With the improvement of technologies at sea, fishing has become so advanced that many fisheries worldwide are facing diminished stock statuses. Incorporating selective designs to trawl nets separate species by mechanical or behavioral mechanisms to reduce bycatch and discards at sea. By exploiting behavioral differences between round fish and flatfish, species can be selected to be retained and caught or given escape opportunities. Modifications to a trawl net to increase species selectivity at the groundgear can allow fish to escape at depth, therefore decreasing the rate of mortality associated with the catch process and contact with the gear itself. The knowledge of how flatfish and roundfish behave around a trawl net led to the creation of an experimental groundgear. The gear was a modified rubber Riser Sweep that incorporated escape windows below the fishing line on the groundgear. The experimental net was tested against a common commercially fished net in southern New England in a comparative pairwise fashion. Two riggings of the experimental groundgear were tested in 2013 and 2014. Catch results indicate that the gear was successful in reducing winter flounder (Pseudopleuronectes americanus) bycatch while targeting Atlantic cod (Gadus morhua). Other bycatch species such as yellow tail (Limanda ferruginea) and windowpane flounder (Scopthalmus aquosus), winter (Leucoraja ocellata) and little skate (Leucoraja erinacea), longhorn sculpin (Myoxocephalus octodecemspinosus), and sea raven (Hemitripterus americanus) were also dramatically reduced in the experimental net. Though the reduction in bycatch species was accomplished as a primary goal, Atlantic cod catches decreased in the experimental net in 49 out of 66 pairs over both years of sea trials. While the experimental gear showed promise in reducing bycatch, further modifications are needed to reduce loss of target species.
Download or read book Can Fishing Gear Protect Non target Fish Design and Evaluation of Bycatch Reduction Technology for Commercial Fisheries written by Brett Favaro and published by . This book was released on 2013 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The impacts of commercial fishing extend far beyond direct effects on targeted species. As much as 40% of global marine catch is attributable to bycatch, or the capture of non-target organisms which occurs during fishing. The amount of bycatch in a fishery is determined in part by the selectivity of the industry's fishing gear, and bycatch mitigation often focuses on improving the selectivity of these gears. This thesis explores bycatch mitigation through the design and evaluation of bycatch reduction devices (BRDs), or fishing gear modifications aimed specifically at reducing non-target catch while maintaining the catch of target species. I examine BRDs using a three-pronged assessment, which tests a modified gear's effects on non-target catch, on target catch, and on practicality for use in commercial fisheries (all relative to unmodified gear). I first perform a global-scale meta-analysis on technologies designed to protect elasmobranchs (sharks and rays) from longline fisheries. I show that most technologies are broadly ineffective at reducing elasmobranch bycatch, and that many studies fail to adequately assess novel BRDs across all three dimensions of gear performance. The remainder of my thesis focuses on the research and development of BRDs for a British Columbia fishery which employs trapping gear to capture spot prawns (Pandalus platyceros). Using data from fishery-independent surveys, I show that these traps catch rockfish (Sebastes spp.) as bycatch, a multi-species genus which is depleted due to overfishing and which suffers high discard mortality due to barotrauma incurred during the fishing process. I demonstrate that a novel underwater camera system can be used to study prawn traps in situ, and use insights from this analysis to inform the design of BRDs for prawn traps. I conclude my thesis with an assessment of BRDs of my own design, using both catch data and in situ observations conducted using my underwater camera apparatus. Overall, this thesis demonstrates the challenges in designing effective BRDs, and provides a framework for assessment that can be used as a template in future studies of fishing gear design.
Download or read book Reduction of Flatfish Bycatch in the Small Mesh Bottom Trawls Used in the New England Silver Hake Fishery written by Henry O. Milliken and published by . This book was released on 2000 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shifting Gears written by Lance Edward Morgan and published by . This book was released on 2003 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seabird Bycatch written by Edward F. Melvin and published by Alaska Sea Grant College Program. This book was released on 2001 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seabird Bycatch significantly adds to the knowledge base of seabird mortality in commercial fisheries, and emphasizes the importance of comprehensive solutions. The product of a 1999 symposium held by the Pacific Seabird Group, Seabird Bycatch is a response to escalating bycatch, a global conservation and fisheries management issue.
Download or read book Mortality of Fish Escaping Trawl Gears written by Petri Suuronen and published by Food & Agriculture Org.. This book was released on 2005 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Progress has been made in reducing bycatch and discards through improving the selectivity of fishing gear. This publication examines the key factors affecting the stress, injury and mortality of fish arising from fishing processes, particularly when fish escape from trawl equipment. It seeks to identify improved methodological approaches and practices, and to consider the design of fishing gears and operations that reduce or eliminate such deaths, and to assess the problems associated with estimating the impact of unaccounted fish mortality.
Download or read book Solving Bycatch written by Alaska Sea Grant College Program and published by Alaska Sea Grant College Program. This book was released on 1996 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bycatch, the capture of unmarketable or restricted species during commercial fishing, is a world economic, environmental, and political problem. This proceedings book features international research on bycatch reduction methods and gear devices, presented at a 1995 workshop in Seattle, Selected by the Journal of Government Information as an outstanding publication.
Download or read book Overview of mitigation measures to reduce the incidental catch of vulnerable species in fisheries written by Sacchi, J. and published by Food & Agriculture Org.. This book was released on 2021-06-23 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Potentially harmful contact between fisheries and marine vulnerable species represents a global conservation issue and efforts to mitigate the negative repercussions of these interactions belong in strategies for ensuring the sustainability of fisheries. This literature review offers a survey of mitigation measures and techniques that have been developed and tested around the world, aiming to address both the incidental catch of highly mobile species – specifically, cetaceans, seabirds, sharks and rays, and sea turtles – and depredation caused by dolphins. Based on research detailed in over 300 documents, including peer-reviewed publications, reports from international organizations and papers available on the internet, most of the mitigation techniques illustrated are still under development, with only a few already adopted through legislation. The selected mitigation measures are grouped by main types of fishing gear – gillnets and trammel nets, longlines and lines, trawls, purse seines, traps and pots – and further subdivided according to which of the four main groups of vulnerable species – cetaceans, seabirds, sharks and rays, or sea turtles – they are designed to protect. Preventive and curative approaches covering both technical measures (gear modifications, strategies, as well as acoustic, visual, magnetic and chemosensory deterrents) and management measures are described.
Download or read book Conference Proceedings Gear Selectivity as a Management Tool written by Clifford A. Goudey and published by . This book was released on 1986 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Behavior of Marine Fishes written by Pingguo He and published by John Wiley & Sons. This book was released on 2011-06-09 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: BEHAVIOR OF MARINE FISHES BEHAVIOR OF MARINE FISHES: Capture Processes and Conservation Challenges Understanding fish behavior in relation to capture processes in marine fisheries is of fundamental importance to reducing bycatch and discards, and to enhancing marine fisheries conservation efforts. A thorough understanding of this allows commercial fishers to more effectively capture target species while reducing the catch of unwanted species. Behavior of Marine Fishes: Capture Processes and Conservation Challenges provides the reader with principles, patterns, and characteristics on fish behavior and fish capture processes using several types of important commercial fishing gears. The book also highlights conservation challenges facing the marine capture fisheries in efforts to maintain sustainable use of marine resources and to reduce negative impacts to the marine ecosystem. This volume, with contributions from leading applied fish behaviorists and fishing gear technologists from around the world, will be a valuable reference for researchers, fishing gear technologists, fisheries managers, students, and conservationists. SPECIAL FEATURES: Synthesis of current research and valuable knowledge that will help reduce bycatch and discards in commercial fisheries Review of basic fish behavioral principles and patterns and their relation to capture methods and conservation efforts Contributions from leading international applied fish behaviorists and fishing gear technologists
Download or read book Bycatch Reduction in the Directed Haddock Bottom Trawl Fishery written by David L. Beutel and published by . This book was released on 2006 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of employing a large mesh faced (top, bottom, and side wings) bottom trawl designed to capture haddock while reducing the bycatch of cod as well as other species was investigated. This experimental net, named the "Eliminator Trawl," exploits the differences in fish behavior. Two vessels, F/V Iron Horse and F/V Sea Breeze, conducted side-by-side comparison hauls with one vessel towing the control net (currently regulated specifications) and the other towing the experimental net. A total of 100 successful tows were completed. All species captured were weighed for total weight. Haddock, cod, and the majority of the flounders caught were measured. The "Eliminator Trawl" significantly reduced the catch of stocks of concern including Georges Bank (GB) cod, GB yellowtail flounder, GB winter flounder, witch flounder, and American plaice. Other species such as monkfish and skate also showed significant decrease in catch in the experimental net. In addition, the catch of GB haddock, the target species, did not differ significantly between nets. The results of this study indicate that the "Eliminator Trawl" would be an efficient tool in the B Days-at-Sea Program as well as a Special Access Program as it appears to meet the minimum bycatch requirements to be considered for both these programs.
Download or read book Status Report on the Potential of Gear Modifications to Reduce Finfish Bycatch in Shrimp Trawls in the Southeastern United States written by John William Watson and published by . This book was released on 1993 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction of Large Mesh Webbing in the Belly of a Traditional Shrimp Trawl to Reduce Bycatch in Inshore Waters written by Jeffrey L. Gearhart and published by . This book was released on 1996 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Species Composition of Industrial Trawl fish Landings in New England 1958 written by Robert L. Edwards and published by . This book was released on 1960 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Trawl Rationalization Trailing Actions Chafing Gear written by L.B. Boydstun and published by . This book was released on 2014 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The action modifies chafing gear regulations that apply to all midwater trawl gear used in the Pacific Coast groundfish fishery. Chafing gear is webbing or other material attached to the codend to minimize damage from rubbing against the stern ramp and from contact with the ocean floor. The proposed action is neither expected to compromise the sustainability of any target or non-target species, nor is it expected to result in significant social or economic impacts interrelated with significant natural or physical environmental effects. Increased chafing gear coverage may result in fewer small fish escaping from the codend by reducing the effective mesh size or creating the effect of a double-walled codend. Small fish include juvenile Pacific whiting and non-groundfish species such as coastal pelagic species, eulachon, and small forage fish. Eulachon is listed as threatened under the Endangered Species Act. Because vessels targeting Pacific whiting have less market opportunity for small fish, they are expected to take measures to reduce the catch of small unmarketable Pacific whiting. The catch of small non-target species, including eulachon is not expected to increase substantially. Eulachon will continue to be monitored and managed to stay within thresholds identified in the current Endangered Species Act Section 7 biological opinion for the groundfish fishery. Increased chafing gear coverage may result in midwater trawl gear being used to fish in a manner that results in more contact with ocean floor than is currently occurring. Historical data indicate that the midwater trawl gear used to target Pacific whiting does occasionally make contact with the ocean floor (approximately 8 percent of the hauls). The vulnerability of the net to damage from bottom contact means that increases in chafing gear are not likely to result in substantial increases in bottom contact. The expected impact to EFH and bottom habitat is minor"--Cover letter summary.
Download or read book Marine Mammals and Fisheries written by J. R. Beddington and published by Unwin Hyman. This book was released on 1985-01-01 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
