Fisheries Management and Ecology最新文献

Fishery independent surveys provide valuable data for fisheries assessments that predominantly rely on trends in catch per unit effort (CPUE). Many crustacean fisheries are harvested using traps, so this gear is often used for fishery independent surveys. The areal sampling unit for baited traps is normally poorly understood, so surveys can be biased if sampling areas overlap. The blue swimmer crab (Portunus armatus) is an important commercial and recreational species distributed around the warm temperate and tropical coast of Australia, and stock management typically relies on catch data supplemented by independent surveys. Acoustic telemetry was used to track fine-scale movements of 37 crabs in response to deployment of baited-traps and to estimate probability of capture relative to distance from the trap. Traps attracted crabs from an initial distance up to 70 m, with most movements towards traps after dark. Capture probability increased with decreasing initial distance from a deployed trap. Despite this, the probability of capture was < 50% for crabs positioned adjacent to a deployed trap, which could lead to a mismatch between catch and crab abundance if the proportion of catchable crabs varied with abundance. Our findings reinforced that nocturnal sampling was more appropriate for the species, and we recommend that traps be no closer than 140 m apart. Our findings also demonstrated the utility of fine-scale acoustic telemetry for informing survey designs and may serve as a template for other trap surveys and fisheries.

Coastal fishery resources shared by Belize and Mexico emphasize the need for bi-national conservation and management strategies. We used the recreational flats fishery as a model to: (1) evaluate the strengths and weaknesses of a mixed-methods approach for fishery conservation and management and (2) propose a general strategic plan to guide conservation and management that also benefits biodiversity of aquatic resources. The approach consisted of gathering local knowledge, observing participants, reviewing literature, and interviewing key representatives of the flats fishing community, resource managers (governmental and co-managers), academia and non-governmental organizations, followed by online surveys, to rank overall findings and prioritize concerns identified by a Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis. Our findings indicated that science, education, conservation, and management were important. The strategic framework included goals, objectives, strategies, and outcomes that will depend on validation and collaboration amongst sectors to generate information and application to fisheries and protected areas (PAs) management to benefit local communities, national economies, and preservation of biodiversity. Prioritized needs included: (1) science to address habitat loss and degradation, overharvest, habitat use conflict resolution, fishing pressure, and protection of key habitats for all life cycles of target species; (2) education and awareness to increase knowledge, address fish handling practices, and guide conservation and management decision-making; (3) inclusion of the flats fishery in conservation plans, PAs, development, and economic plans; and (4) improved enforcement of regulations to ensure sustainability.

Estuarine fisheries are of high regional socio-economic importance worldwide, by providing an important livelihood for many families. The Portuguese green crab (Carcinus maenas) fishery was assessed using a socio-economic assessment to understand the importance of the fishery and a stock assessment analysis to determine the exploitation status of the fishery during 1960–2020. Fisher knowledge revealed that crab fishing was a family affair that provided a livelihood for hundreds of families directly targeting crabs, with catches exported to Spain during 1960–1990s, and in later years, crab demand increased as bait for octopus fishing. Despite its socio-economic importance, the fishery was regulated without a scientific basis and economic value of crabs remained similar through time. Annual landings never exceeded sustainable catch rates, but engagement in the crab fishery declined due to low economic value of crabs compared to other fisheries and regulatory hurdles. Consequently, the number of fishermen declined to 20–30 elderly men fishing on the largest estuaries, with the fishery currently on the verge of extinction. Fishers pointed to a reduction in the minimum landing size and enforcement of crab-specific trap regulations as ways to avert fishery decline. Such changes would stimulate recruitment of new crab fishers, while reducing fishing pressure on other estuarine resources through fisheries diversification.

This paper outlines the scientific achievements of Gordon H. Copp (1956–2023) in fish biology and invasion science as presented in his Doctor of Science portfolio. Gordon's mentorship began during his postdoctoral research and expanded to involve students, early-career researchers as well as prominent fish biologists in a vast number of research projects. Early in his career, Gordon was involved in the study of floodplain fish communities for which he developed a novel technique for sampling young-of-year (0+) fish and in the early ontogeny of fishes. Gordon's later involvement in non-native species policy has been pivotal, from developing risk analysis schemes for freshwater fishes to advising on EU and UK regulations. Gordon's research throughout his entire career on the pumpkinseed sunfish Lepomis gibbosus as a model species highlights his focus on understanding and predicting invasiveness under varying climate conditions, contributing to a broader understanding of non-native species impacts.

Saltwater angling is a culturally significant and economically vital coastal recreational activity, particularly in the Gulf of Mexico that attracts enthusiasts worldwide and contributes significantly to the well-being of Gulf Coast communities. However, angling can threaten ecologically important species, notably sea turtles, which are federally protected under the Endangered Species Act. In commercial fisheries, using circle hooks over traditional “J” hooks and using specific bait types can reduce sea turtle bycatch and fishing gear interactions. However, angler willingness to use these techniques is unknown. Our study aimed to assess the willingness of recreational anglers to adopt tackle modifications to support sea turtle conservation. A mixed-mode survey was used to gather data on angler knowledge, behaviors, and attitudes toward sea turtle conservation. Generalized linear models were used to examine factors associated with angler willingness to adopt sea turtle-friendly practices. Factors such as gender, state residency, recreational and fishing motivations, and ecological knowledge influenced angler willingness to adopt sea turtle-friendly tackle modifications. We conclude that conservation strategies and educational outreach must be tailored to specific fishery management objectives.

We estimated relative abundance of South Atlantic Swordfish (Xiphias gladius), a highly migratory marine species, from commercial fishing data using a three-step analysis protocol. First, we modeled catch rate based on variables affecting the catch rate to rule out effects of catchability-related factors. Next, we analyzed residuals to identify autocorrelation. Last, we used an area-weighed recursive algorithm that considered spatial autocorrelation for each year within the analysis period. Commercial South Atlantic swordfish catch data from the Brazilian pelagic longline fleet were analyzed. Swordfish accounted for the highest spatial dependence in distance in 2005 (456 km), 2008 (111 km), 2012 (80 km), and 2014 (443 km), as well as for the lowest in 2011 and 2013 (average = 15.45 km). A downward trend in swordfish abundance between 2010 and 2017 was detected several years earlier than conventional standardized indices, so our proposed index is an alternative, and potentially more accurate, index of swordfish population dynamics in the South Atlantic. Our findings highlight the need to integrate multiple approaches into assessments of the abundance of marine species.

Contamination of estuaries with per- and polyfluoroalkyl substances (PFAS), such as perfluorooctane sulfonate (PFOS), may impact recreational fishers who consume their catch. However, the presence and concentration of PFAS across commonly harvested estuarine taxa is rarely quantified. We used data from a state-wide survey of recreational fishers to design and conduct a sampling program for assessing PFAS contamination across two recreational fishing havens (Lake Macquarie and Botany Bay, New South Wales, Australia). Perfluorodecanoic acid (PFDA) and PFOS were the primary contaminants in edible tissues of recreationally harvested species, and concentrations were highly variable. In Lake Macquarie, all samples were below screening criteria, as were invertebrates in both estuaries. In Botany Bay, some fish exceeded screening criteria, but the most frequently harvested recreational species had the lowest concentrations of all fish across both estuaries. Ecological factors likely contributed to substantial variation in PFAS accumulation levels among different recreational species. Recreational fisheries surveys provide a solid foundation to frame investigations of exposure risk and support the development of spatially tailored dietary advice.