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.

Bycatch – a term widely used to refer to part of the catch unintentionally caught during a fishing operation, in addition to target species, and consisting of the discards and incidental catch of vulnerable species – is considered one of the most important threats to the profitability and sustainability of fisheries, as well as to the conservation of the marine environment and ecosystems. Understanding the bycatch issue and adopting effective measures in order to reduce bycatch rates are essential steps towards minimizing the impacts on vulnerable species and ensuring both a sustainable fisheries sector and healthy seas. In the Mediterranean and the Black Sea, the incidental catch of vulnerable species – namely seabirds, sea turtles, elasmobranchs, marine mammals and macrobenthic invertebrates – represents one of several challenges for the industrial, semi-industrial and small-scale fisheries that coexist in the region, as well as for the diverse and sensitive ecosystems impacted. Typically, data on this issue have been collected in an opportunistic manner and in ways that make comparisons difficult. The annual absolute values of incidental catch of vulnerable species are not available: studies cover only a small portion of the total fishing activity and often present important knowledge gaps for many types of fishing gear, countries and/or subregions, as well as on temporal scales, for example, to establish reliable baselines. The result is that little is known of the scope of the problem, despite incidental catch being a significant pressure on the populations of vulnerable species, as well as a concern for fishers.This regional review is an attempt to compile, in one single document, all available data and historical records on the incidental catch of vulnerable species in the Mediterranean and Black Sea fisheries, obtained from existing literature, databases and other grey sources, and collated in a standardized and comparable way. The main objective is to provide comprehensive baseline information, earmark the main data gaps, as well as identify the most impacting types of fishing gear by taxonomic group. This work is a reminder of the importance of standardized data collection and the need to have baseline information in order to support decision-making in the identification of appropriate bycatch mitigation techniques, thus enabling analysis of their effectiveness and comparison over time and space, as well as facilitating the implementation of relevant conservation and/or management measures at the national, subregional and regional levels.

Bycatch – a term widely used to refer to the part of catch unintentionally captured during a fishing operation, in addition to target species, and consisting of discards and incidental catches of vulnerable species – is considered one of the most important threats to the profitability and sustainability of fisheries, as well as to the conservation of the marine environment and ecosystems. In the Mediterranean, studies on the incidental catch of vulnerable species cover only a small portion of the total fishing activity. In addition, there are several important knowledge gaps for many types of fishing gear, and several countries and/or subregions, as well as on temporal scales, and only a few measures are in place that address the protection of vulnerable species. Monitoring programmes and surveys on incidental catches, which follow a harmonized methodology allowing for results to be compared across subregions, are necessary to improve knowledge on the issue and to subsequently support the identification of potential mitigation methods and tools, and relevant management measures. This publication and the methodology contained herein aim to provide a framework for the development and implementation of an efficient, standardized data collection and monitoring system for all vulnerable species encountered in the Mediterranean and the Black Sea, namely elasmobranchs, marine mammals, seabirds, sea turtles, and macrobenthic invertebrates.

"This final action will modify the permitting and retention requirements for Atlantic HMS to address the incidental catch of North Atlantic swordfish in the Illex squid trawl fishery, and the incidental catch of species in the smoothhound shark complex (genus Mustelus) in all Atlantic trawl fisheries. The action will reduce regulatory dead discards of incidentally caught swordfish in the Illex squid trawl fishery by establishing a new Incidental HMS Squid Trawl permit. It will also establish a retention limit for smoothhound sharks in all Atlantic trawl fisheries. This action will be consistent with the 2006 Consolidated Atlantic Highly Migratory Species Fishery Management Plan. The action is not expected to significantly alter current fishing practices or increase fishing effort, and is not be expected to change previously analyzed endangered species or marine mammal interaction rates or magnitudes, or affect critical habitat"--Cover letter; Portfolio comprised of two related PDF documents digitized and organized by: NOAA Office of Program Planning and Integration (PPI) National Environmental Policy Act (NEPA) staff.

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.