Search

The glass eel catch from the international River Minho, western Iberian Peninsula, forms the southernmost Atlantic series in the composite index outside the North Sea assessing European eel recruitment. Here, new experimental yield data from the lower estuary (1981–2022) and fishers´ daily records (1990–2022) were modelled to describe and compare seasonal and interannual trends. Seasonality matched river discharge climatology, possibly a more general feature in the southern range of the species distribution, with the difference between high and low season becoming less marked in recent periods of lower abundance. Glass eel yield showed a sharp decline during the 1980s, in line with the recruitment index outside the North Sea and with total Minho catch, but not with recent local estimates of catch per unit effort. This decline is corroborated by trends in fishers´ daily records, suggesting that the reduction in effort in the Minho was the consequence of a gradual adjustment to recruitment in the catchment mediated by progressively tighter local management measures. The inefficiency of fisheries regulatory measures to guarantee stock recovery alone calls for more comprehensive measures to reverse anthropogenic impacts on continental eel populations, but the task seems Herculean. [ABSTRACT FROM AUTHOR]

Three sardine species of Harengula and one of Opisthonema (Clupeiformes, Clupeidae) are known in the Western Atlantic, where the Amazon-Orinoco plume has been recognized as a major biogeographic barrier, albeit permeable to larger and generalist species. Here we used mitochondrial cox1 gene DNA sequences to check the lineage delimitation of both genera, testing the influence of the Amazon-Orinoco barrier (AOB) and marine provinces on their phylogeographic structure. Results indicate that the two genera are differently affected by the AOB, including cryptic speciation in Harengula and population structure in Opisthonema. Harengula show a broad distribution in the Brazilian Province (BRA) distinct from H. clupeola and H. jaguana from the Greater Caribbean Region (GCR). Divergence time between Harengula from the GCR vs. BRA was estimated as about 2.4 Mya, which coincides with the period of increasing sediment and freshwater discharge of the Amazon River in the Atlantic. Results also indicate the existence of a single species of Opisthonema, albeit with population structuring related to the marine provinces. Since species of both genera are relevant to artisanal fisheries and the maintenance of oceanic ecosystems, these results may help in fisheries management of these important marine resources. [ABSTRACT FROM AUTHOR]

Understanding population connectivity helps inform resource and conservation managers about appropriate boundaries for management units. However, for many species facing recent increases in fishing or environmental pressure, accurate information on population structure is lacking. Reef Bugs (Thenus australiensis), commonly known as Moreton Bay Bugs, are iconic shovel-nosed lobsters in northern Australia and an increasingly important fisheries resource. Around 80% of landings occur in the Queensland East Coast Otter Trawl Fishery (ECOTF) where the first stock assessment of the species is underway. However, knowledge about population structure to inform stock assessment is lacking. We used genome complexity reduction-based sequencing to characterise high-quality Single Nucleotide Polymorphisms (SNPs) used to evaluate population structure among three management zones of the ECOTF. Post-filtering, a total of 3,031 SNPs were used to infer no genetic differences among locations indicating strong genetic population connectivity. The presence of a single panmictic population was further supported by cluster and kinship analyses. Broad-scale genetic connectivity likely results from pelagic larval dispersal due to limited adult movements. Findings of high gene flow among connected populations indicate a single biological stock of T. australiensis on Australia's east coast and will inform future fisheries management initiatives. [ABSTRACT FROM AUTHOR]

Extreme weather events across coastal environments are expected to increase in frequency under predicted climate change scenarios. These events can impact coastal recreational fisheries and their supporting ecosystems by influencing the productivity of fish stocks or altering behaviours and decision-making among fishers. Using off-site telephone/diary survey data on estuarine and oceanic recreational fishing activity in eastern Australia, we analyse interannual and geographic variability in bream (Acanthopagrus spp) and snapper (Chrysophrys auratus) catch, total effort and total catch per unit effort (CPUE) through a period (2013/2014, 2017/2018 and 2019/2020) that encompassed severe drought, bushfires and flooding. Interacting spatial and temporal differences were detected for bream and may reflect spatial variation in the intensity and extent of some of the extreme weather events. The catch of snapper did not change temporally, providing little evidence that this species' catch may be influenced by the extreme weather events. Independent bioregional and temporal effects on effort were detected, while CPUE only showed significant bioregional differences. Although adverse conditions created by the extreme weather events may have dissuaded fisher participation and impacted effort, we propose that the observed temporal patterns in effort reflect the early influence of socio-economic changes brought on by the COVID-19 pandemic on coastal recreational fishing, over and above the impacts of extreme weather events. This study demonstrates how interrelated ecological, social and economic factors can shape coastal recreational fisheries and facilitates development of management strategies to address future threats to the sector. [ABSTRACT FROM AUTHOR]

Climate change is anticipated to have long-term and pervasive effects on marine ecosystems, with cascading consequences to many ocean-reliant sectors. For the marine fisheries sector, these impacts can be further influenced by future socio-economic and political factors. This raises the need for robust projections to capture the range of potential biological and economic risks and opportunities posed by climate change to marine fisheries. Here, we project future changes in the abundance of eight commercially important fish and crab species in the eastern Bering Sea and Chukchi Sea under different CMIP6 Shared Socioeconomic Pathways (SSPs) leading to contrasting future (2021–2100) scenarios of warming, sea ice concentration, and net primary production. Our results revealed contrasting patterns of abundance and distribution changes across species, time periods and climate scenarios, highlighting potential winners and losers under future climate change. In particular, the least changes in future species abundance and distribution were observed under SSP126. However, under the extreme scenario (SSP585), projected Pacific cod and snow crab abundances increased and decreased, respectively, with concurrent zonal and meridional future shifts in their centers of gravity. Importantly, projected changes in species abundance suggest that fishing at the same distance from the current major port in the Bering Sea (i.e., Dutch Harbor) could yield declining catches for highly valuable fisheries (e.g., Pacific cod and snow crab) under SSP585. This is driven by strong decreases in future catches of highly valuable species despite minimal declines in maximum catch potential, which are dominated by less valuable taxa. Hence, our findings show that projected changes in abundance and shifting distributions could have important biological and economic impacts on the productivity of commercial and subsistence fisheries in the eastern Bering and Chukchi seas, with potential implications for the effective management of transboundary resources. [ABSTRACT FROM AUTHOR]

Commercial fisheries along the US West Coast are important components of local and regional economies. They use various fishing gear, target a high diversity of species, and are highly spatially heterogeneous, making it challenging to generate a synoptic picture of fisheries activity in the region. Still, understanding the spatial and temporal dynamics of US West Coast fisheries is critical to meet the US legal mandate to manage fisheries sustainably and to better coordinate activities among a growing number of users of ocean space, including offshore renewable energy, aquaculture, shipping, and interactions with habitats and key non-fishery species such as seabirds and marine mammals. We analyzed vessel tracking data from Vessel Monitoring System (VMS) from 2010 to 2017 to generate high-resolution spatio-temporal estimates of contemporary fishing effort across a wide range of commercial fisheries along the entire US West Coast. We identified over 247,000 fishing trips across the entire VMS data, covering over 25 different fisheries. We validated the spatial accuracy of our analyses using independent estimates of spatial groundfish fisheries effort generated through the NOAA's National Marine Fisheries Service Observer Program. Additionally, for commercial groundfish fisheries operating in federal waters in California, we combined the VMS data with landings and ex-vessel value data from California commercial fisheries landings receipts to generate highly resolved estimates of landings and ex-vessel value, matching over 38,000 fish tickets with VMS data that included 87% of the landings and 76% of the ex-vessel value for groundfish. We highlight fisheries-specific and spatially-resolved patterns of effort, landings, and ex-vessel value, a bimodal distribution of fishing effort with respect to depth, and variable and generally declining effort over eight years. The information generated by our study can help inform future sustainable spatial fisheries management and other activities in the marine environment including offshore renewable energy planning. [ABSTRACT FROM AUTHOR]

Impacts of climate change are evident and intensifying for coastal communities and natural resource-dependent stakeholders. As climate impacts mount, so does the need to understand mechanisms that enable and impede proactive adaptation. Through two years of focus groups and interviews with fisheries participants in the Gulf of Alaska, we explore subjective climate change attribution—the expressed connection between an observed ecosystem change and climate change itself—amongst fisheries stakeholders, and its extension to other stakeholders and coastal communities. Participants’ observations differentiate fishing communities’ experiences of climate change, revealing perceptions of marine heatwave impacts and trends in target and non-target fishery species. We interrogate these findings through models for climate attribution, risk appraisal, and adaptive capacity. Fishermen (We use the term fishermen instead of fishers in keeping with how those participating in the fishing industry in Alaska refer to themselves, irrespective of their gender) recognize tremendous ecosystem change but convey a mismatch between those observations and climate attribution. Perceptions of individual risk and adaptive capacity are complicated by psychological roadblocks, opportunity costs, and a lack of perceived options for adaptation. Yet fishermen’s discussion reveals pathways to reconcile observations of change with attribution, risk appraisal, and adaptive capacity, especially with science in a critical role to bridge the gaps within and across these processes for fishermen, natural resource users, and coastal communities more broadly. [ABSTRACT FROM AUTHOR]

Machine learning occupies a central position in the modeling of fish distribution patterns. The augmentation of explanatory variables in fish habitat through many kinds of observational methodologies necessitates the discernment of an optimal combination of these variables for fish distribution modeling. We proposed a feature selection technique, recursive feature elimination with cross-validation (RFECV), to determine optimal variables combinations for yellowfin tuna distribution in the Pacific Ocean. Four tree-based models, random forest, eXtreme Gradient Boosting, Light Gradient Boosting Machine, and categorical boosting driven by RFECV, were developed using comprehensive fisheries and biotic/abiotic data. Habitat variables including sea temperature, dissolved oxygen concentration, chlorophyll-a concentration, sea salinity, and sea surface height were identified as significant features by all models. The models were trained using the corresponding selected variables, and these trained models were employed to predict the spatiotemporal distribution of yellowfin tuna from 1995 to 2019. The results obtained could inform useful knowledge for the sustainable exploitation of yellowfin tuna in the Pacific Ocean and furnish a benchmark of feature selection for machine-learning-based distribution modeling of other pelagic species. [ABSTRACT FROM AUTHOR]

Kaniatarowanenneh (the St. Lawrence River) is the outflow of one of the world's largest freshwater ecosystems and its ecological health has implications for resource management. The population dynamics of an ecologically and economically important fish, the Wa hia hé:ta, Mohawk for yellow perch (Perca flavescens), are considered by including data that extend to the past century to redress temporal gaps in comparative literature. We found both a significant top-down effect from piscivorous fish as well as a significant bottom-up effect related to total phosphorus on yellow perch relative abundance in the Lake Ontario–Upper St. Lawrence system. Regarding the bottom-up effect, the current state of yellow perch reflects the population size prior to cultural eutrophication (pre-1940s/50s) likely responding to the re-oligotrophication of the system. These findings emphasize the importance of considering historical records in fish population dynamics research to incorporate shifting population baselines into fisheries management. The study also demonstrates the need for collaborative approaches that bring critical new insights and multivocality. [ABSTRACT FROM AUTHOR]

Notwithstanding the continuing advancement of our understanding of the broader ecosystem functioning in Lake Ontario, emerging evidence suggests that there are fundamental knowledge gaps to accurately describe the relationship between exogenous phosphorus (P) loading and in-lake total phosphorus (TP) concentrations. The whole-lake load appears to frequently exceed the Great Lakes Water Quality Agreement (GLWQA) interim target of 7000 metric tonnes·year−1, although the offshore-water P concentrations are consistently below the GLWQA interim substance concentration objective of 10 µg TP·L–1. Contrasting ecological conditions prevail in different locations of Lake Ontario, owing to the significant urban footprint along the shoreline but also the capacity of dreissenid mussels to sequester P in the littoral zone. Specifically, low ambient P levels threaten fisheries productivity in offshore waters, while nuisance benthic algae (predominantly Cladophora) and toxin-producing cyanobacteria blooms affect the water quality in the nearshore zone. The present study offers a technical analysis of the recent and ongoing modelling work that has been conducted in Lake Ontario and can be potentially used to address the multitude of ecosystem management challenges. Our aim is to provide an overview of all the major models developed by identifying their fundamental assumptions, structural attributes, and general consistency against empirical knowledge derived from the system. The existing modelling work has opted for parsimonious representations of the lower food web coupled with granular grid configurations to effectively link hydrodynamic processes and mass transport between nearshore and offshore waters. The establishment of comprehensive ecophysiological modules that will recreate the mechanisms underlying the interplay among bioavailable phosphorus, planktonic dynamics, dreissenid mussels, and Cladophora is a critical undertaking to reproduce the water quality conditions in the nearshore zone of Lake Ontario. Striving to integrate the lower food web with fisheries and ecosystem-service modelling, we also offer a technical analysis of knowledge gaps and monitoring-assessment objectives that should be addressed to ensure that ecosystem processes of management interest are adequately measured and the local modelling enterprise is focused on suitable performance indicators. [ABSTRACT FROM AUTHOR]

Economies and livelihoods in the Caribbean strongly depend on the terrestrial and marine natural resource base. There are critical gaps in quantitative data and the contextual and compositional factors affecting perceptions of changes in ecosystems and natural resources. This paper used interview data from 441 households in Belize, Dominican Republic, and Suriname to explore the contextual and compositional determinants of perceptions of change in the quality of the terrestrial, coastal/marine environment and natural resources as a composite variable. The outcome variable comprised changes in fishing effort, marine and coastal environment, forest cover, agricultural land area, and soil fertility, and relationships with predictor variables were explored using univariate, bivariate, and three multivariate models. At the univariate level, most respondents in Belize and Suriname reported perceiving a significant increase in fishing effort (i.e. days and fuel spent at sea) and a decrease in forest cover, quality of the coastal/marine environment, area of agricultural land, and fertility and productivity of soils. Sex, marital status, household size, and years of experience were not significantly associated with the terrestrial variables and fishing effort. Sex was only significantly associated with the quality of the marine environment. At the multivariate level, the elderly, high school education, and household incomes were associated with a lower perception of the outcome variable. It is concluded that policy and interventions should strongly consider ethnicity and community, and improve education and household incomes to enhance perceptions of changes in the quality of the terrestrial and coastal/marine environment in the studied countries. [ABSTRACT FROM AUTHOR]

Terrestrial subsidies are important for freshwater ecosystems and, in lakes supporting recreational fisheries, angling baits can represent an important allochthonous input. This resource can directly contribute to fish diet but its consumption may be influenced by fish body size and the type of angling baits used in different fisheries. In this study, we evaluated angling baits consumption by two common cyprinid species, Cyprinus carpio and Rutilus rutilus, in three fishery types (specialised carp, specialised roach, and put‐and‐take fisheries).We used stable isotope analyses (δ13C and δ15N) of cyprinids, their natural prey and different angling baits in 16 gravel pit lakes located in south‐western France, including four lakes without angling.Angling baits were significantly δ13C‐enriched and δ15N‐depleted compared to natural prey. Overall, angling bait consumption was highly variable between individuals. For C. carpio, angling bait consumption averaged 30.5% (±17.0 SD) and was higher in specialised carp fisheries (40.0% ± 16.7 SD) than in put‐and‐take fisheries (15.9% ± 9.0 SD) and was not related to body size. For R. rutilus, angling bait consumption averaged 41.3% (±15.7 SD), did not differ significantly among fishery types, but increased with body size. The niche width of C. carpio was six times larger in specialised carp fisheries than in lakes without angling. For R. rutilus, niche width was two times larger in specialised carp and put‐and‐take fisheries compared to lakes without angling and specialised roach fisheries.These results indicate that angling bait subsidies represent a novel and substantial resource opportunity for fishes in angling lakes, with trophic consequences for the targeted species through increase of their stable isotope niche size. These impacts are partly influenced by the type of angling baits used by anglers and the characteristics of the fisheries, suggesting the need for improved quantification of the temporal dynamics of this type of subsidy to better understand its consequences on freshwater fish and recipient ecosystems. [ABSTRACT FROM AUTHOR]

Nowadays, the prevalence of infectious vibriosis soars due to the extensive development of marine fishery, resulting in substantial annual fish mortality. Traditionally, antibiotics have been the preferred treatment for vibriosis worldwide. However, the emergence of antibiotic resistance among Vibrios has prompted the gradual adoption of vaccine therapy. In comparison, vaccines demonstrate superior efficacy, combining efficiency, safety, and cost-effectiveness. Consequently, this paper aims to comprehensively review the current research progress concerning diverse vaccine types, including inactivated and attenuated vaccines, for the prevention and control of vibriosis, as well as offers a prospective outlook on the ongoing research and development endeavors focused on novel vaccine approaches to combat this disease. [ABSTRACT FROM AUTHOR]

Cheirodon interruptus is a small characid widely distributed in South America; it is the species most commercialized as a baitfish in the Pampean region. Harvesting wild fish to supply a market of about two million people exerts a significant impact on fish assemblage and the environment. In search of alternatives to reduce the harvesting impact, growth and time to reach commercial fish size were analyzed and linked to consumer demand to design a strategy for production optimization. Based on the Akaike selection criteria, the use of the logistic model is proposed to estimate growth in C. interruptus aquaculture management. A differential growth by sex was observed, with females reaching a larger final size and males showing higher growth rates. These characteristics are useful to meet demand, optimizing time and space in the production schedule. The combined sequence of growth models and the demand curve show that a total of 5 induced spawning events are necessary to guarantee supply during peak seasonal demand. The results of this study can help to replace current fishing on wild fish populations, contributing to the regulatory frameworks in force and, hence, preventing degradation in fragile Pampean wetlands and aiding their recovery. [ABSTRACT FROM AUTHOR]

Rapid changes in sea ice extent and changes in freshwater inputs from land are rapidly changing the nature of Arctic estuarine ecosystems. In the Beaufort Sea, these nearshore habitats are known for their high productivity and mix of marine resident and diadromous fishes that have great subsistence value for Indigenous communities. There is, however, a lack of information on the spatial variation among Arctic nearshore fish communities as related to environmental drivers. In summers of 2017–2019, we sampled fishes in four estuarine ecosystems to assess community composition and relate fish abundance to temperature, salinity, and wind conditions. We found fish communities were heterogeneous over larger spatial extents with rivers forming fresh estuarine plumes that supported diadromous species (e.g., broad whitefish Coregonus nasus), while lagoons with reduced freshwater input and higher salinities were associated with marine species (e.g., saffron cod Eleginus gracilis). West–East directional winds accounted for up to 66% of the community variation, indicating importance of the wind-driven balance between fresh and marine water masses. Salinity and temperature accounted for up to 54% and 37% of the variation among lagoon communities, respectively. Recent sea ice declines provide more opportunity for wind to influence oceanographic conditions and biological communities. Current subsistence practices, future commercial fishing opportunities, and on-going oil and gas activities benefit from a better understanding of current fish community distributions. This work provides important data on fish spatial distributions and community composition, providing a basis for fish community response to changing climatic conditions and anthropogenic use. [ABSTRACT FROM AUTHOR]

Abandoned, lost, and discarded fishing gear (ALDFG) is a problem that is increasingly of concern to global fisheries resources and the aquatic environment. Nearly 2% of all fishing gear used in marine fisheries is lost to the ocean annually. This has negative impacts on the aquatic ecosystem, which includes but not limited to ghostfishing mortality to commercial, recreational and protected species, degradation of benthic habitat, and change to the ecosystem. Fishing gear left in the sea can drift ashore affecting recreational use of beaches and shorelines and poses hazards to navigation. Most of the research on ALDFG has been in the marine fisheries of the developed world with very few studies in the inland fisheries, mostly in the developing world of sub-Saharan Africa and Asia. This paper reviews and synthesizes literature about the status of ALDFG in inland fisheries globally. Only 16 studies, between 1970 to 2023, that referenced ALDFG causes, levels, impacts, and preventive measures were found. Thus, this review highlights that ALDFG in inland fisheries remains a highly understudied area of aquatic plastic pollution. Further studies are recommended to fully understand its status, extent, and potential environmental impacts. [ABSTRACT FROM AUTHOR]

Strandings have been extensively documented for large mammals, however, a comprehensive survey focusing on batoids is currently lacking. To address this knowledge gap, we conducted a review of available stranding data sourced from iNaturalist, news websites, and published papers. A total of 3.148 reports encompassing 189 batoid species were recovered, revealing the vulnerability of both oceanic and coastal species to strandings. Nevertheless, limited data on life stage, sex, animal condition, and fate hinder a comprehensive understanding of this phenomenon. Putative causes were identified only for a small percentage (6%) of the reports, namely pollution, abrupt environmental alterations, predation, pathologies, and fishing activities. The earliest reported stranding dates back to 1989, with an increase in reports observed since 2019. iNaturalist accounted for the majority (75%) of records, emphasizing its significance as a platform for reporting and monitoring batoid strandings. These strandings were reported in 51 countries, with the coastal areas of California, United States, particularly notable. Among the identified species, Rhinoptera bonasus exhibited the highest number of strandings, with 392 recorded individuals. Alarmingly, more than half of the reports involved threatened species, underscoring the need for increased attention to batoid strandings. To address these issues, we propose the establishment of stranding monitoring networks and the development of a freely accessible global database. In addition, the training of volunteer citizen scientists, the development of rescue and rehabilitation protocols, and manuals of good fishing practices aimed at commercial and recreational fisheries are also recommended. [ABSTRACT FROM AUTHOR]

Argentina is among the 20 largest seafood producing countries in the world, with an annual fish capture of about 800,000 tons. However, national annual fish consumption is low, about 5 kg per capita, and the domestic seafood market is little known. The objective of this study was to contribute to the characterization of seafood in the Argentine market. Monthly landings, presence at points of sale and prices of seafood were analyzed. The seafood data were gathered from official statistics of the Undersecretariat of Fisheries and Aquaculture, statistics from the Central Market of Buenos Aires and surveys conducted in fish shops in the city of Mar del Plata. Based on the monthly seasonal index (SI), price variations throughout the year were studied. Likewise, relative fish prices were determined by using as unit the price of Argentine hake (Merluccius hubbsi), which is the most consumed fish in the country. This study identified the marine species most present in the domestic market and their prices. The presence of the different fish species at the points of sale could not be directly associated with their landing seasons. There was also no direct link between fish prices and quantities landed. No significant seasonal fluctuations in prices were found on seafood products (SI = 90–110), with the exception of hake fillet (SI = 80–113). Many finfishes had a price peak during Easter week. Overall, price patterns suggest that seafood prices in Argentina are mainly determined by demand rather than supply. Further research on seafood traceability and fish consumption is needed to advance the understanding of the seafood market in Argentina. [ABSTRACT FROM AUTHOR]

Fisheries management and conservation require consideration of fish, habitat, and people. In fisheries science, a growing body of research on human values, perspectives, and behaviours around fish—known as 'human dimensions' research—has emerged from the realization that management and conservation require a better understanding of people. Surveys are a common and versatile tool in human dimensions research, but not all surveys are equal. Large-scale, probabilistic surveys draw random samples from known populations (e.g., all license-holding recreational fishers in a jurisdiction) and represent the 'gold standard' in survey research. However, these surveys may fall short of this standard for various reasons. Surveys using non-probabilistic sampling are also common in human dimensions research. Non-probabilistic surveys are attractive to researchers facing time, cost, and other constraints, but differ notably from their probabilistic counterparts: data from non-probabilistic samples are typically unfit for population estimates and other inferences due their uncertain representativeness. Nonetheless, a wealth of research with non-probabilistic data within and outside of fisheries (e.g., in health sciences) suggests that these methods have valid applications and advantages in some contexts. We reviewed the literature on non-probabilistic surveys and sampling in the human dimensions of fisheries, and explored seminal literature from other thematic areas where such methods are common, to better understand their strengths, weaknesses, and applications relative to probabilistic methods. Here, we describe (1) how researchers have used non-probabilistic methods to study the human dimensions of fisheries, (2) how mismatching research questions, objectives, and methods can produce 'awkward surveys,' and (3) how researchers can use non-probabilistic surveys in ways that invoke their methodological strengths. While uncertain representativeness may limit the utility of non-probabilistic data in some contexts, non-probabilistic methods are time- and cost-effective, and have distinct advantages in studies of niche groups and phenomena, emergent or understudied phenomena, and in supplementary roles. [ABSTRACT FROM AUTHOR]

Seabirds interact with fishing vessels to consume fishing discards and baits, sometimes resulting in incidental capture (bycatch) and the death of the bird, which has clear conservation implications. To understand seabird–fishery interactions at large spatiotemporal scales, researchers are increasing their use of simultaneous seabird and fishing vessel tracking. However, vessel tracking data can contain gaps due to technical problems, illicit manipulation, or lack of adoption of tracking monitoring systems. These gaps might lead to underestimating the fishing effort and bycatch rates and jeopardize the effectiveness of marine conservation. We deployed bird‐borne radar detector tags capable of recording radar signals from vessels. We placed tags on 88 shearwaters (Calonectris diomedea, Calonectris borealis, and Calonectris edwardsii) that forage in the northwestern Mediterranean Sea and the Canary Current Large Marine Ecosystem. We modeled vessel radar detections registered by the tags in relation to gridded automatic identification system (AIS) vessel tracking data to examine the spatiotemporal dynamics of seabird–vessel interactions and identify unreported fishing activity areas. Our models showed a moderate fit (area under the curve >0.7) to vessel tracking data, indicating a strong association of shearwaters to fishing vessels in major fishing grounds. Although in high‐marine‐traffic regions, radar detections were also driven by nonfishing vessels. The tags registered the presence of potential unregulated and unreported fishing vessels in West African waters, where merchant shipping is unusual but fishing activity is intense. Overall, bird‐borne radar detectors showed areas and periods when the association of seabirds with legal and illegal fishing vessels was high. Bird‐borne radar detectors could improve the focus of conservation efforts. [ABSTRACT FROM AUTHOR]

Conservation planning traditionally relies upon static reserves; however, there is increasing emphasis on dynamic management (DM) strategies that are flexible in space and time. Due to its novelty, DM lacks best practices to guide design and implementation. We assessed the effect of planning unit size in a DM tool designed to reduce entanglement of protected whales in vertical ropes of surface buoys attached to crab traps in the lucrative U.S. Dungeness crab (Metacarcinus magister) fishery. We conducted a retrospective analysis from 2009 to 2019 with modeled distributions of blue (Balaenoptera musculus) and humpback (Megaptera novaeangliae) whales and observed fisheries effort and revenue to evaluate the effect of 7 planning unit sizes on DM tool performance. We measured performance as avoided whale entanglement risk and protected fisheries revenue. Small planning units avoided up to $47 million of revenue loss and reduced entanglement risk by up to 25% compared to the large planning units currently in use by avoiding the incidental closure of areas with low biodiversity value and high fisheries revenue. However, large planning units were less affected by an unprecedented marine heat wave in 2014–2016 and by delays in information on the distributions of whales and the fishery. Our findings suggest that the choice of planning unit size will require decision‐makers to navigate multiple socioecological considerations—rather than a one‐size‐fits‐all approach—to separate wildlife from threats under a changing climate. [ABSTRACT FROM AUTHOR]

By introducing Territorial Use Rights for Fisheries (TURF), the Chilean government has devolved authority over the appropriation of benthic fisheries to local fishers' organisations. Yet there is little evidence of how this local governance works for membership organisations. Drawing on the theory of lateral network governance, the role of legitimacy in governance outcomes is examined by conducting a comparative case study of two TURF networks in northern Chile. Counterintuitively, more effective governance outcomes were found in the TURF network characterised by a less favourable legitimacy structure of decision-making than the case with a better legitimacy structure. Considering context and network evolution, it is suggested that although organisational renewal and high membership turnover potentially fragment legitimacy, they also enable novel collective action and better governance outcomes. The observed divergence of actual legitimacy from formal governance structure underscores the need for dynamic analysis of collective resource governance beyond the formal chart. [ABSTRACT FROM AUTHOR]

The marine fisheries of Bangladesh have experienced an uncontrolled expansion of fishing over the last few decades. Consequently, most fish stocks became vulnerable to overfishing. Similar to many other fisheries, catch of white sardine (Escualosa thoracata) is rapidly declining. Therefore, three data‐limited approaches (length‐based Bayesian biomass analysis, LBB; length‐based spawning potential ratio, LB‐SPR; and Froese's length‐based indicators, LBIs) were used to estimate growth, mortality, and fisheries reference points to evaluate stock status of the white sardine fishery. Results revealed that the fishery is being overfished: F/M = 1.32 years−1 in LBB and 6.67 years−1 in LB‐SPR. However, the stock biomass is still good with B/B0 = 0.43 and B/BMSY = 1.20. Stock indicators revealed that the fishery was mainly targeting mature fishes, most of which were mega‐spawners (older, larger fish), which suggested stocks were recruitment overfished. Harvesting an optimum size range (6.57 to 8.03 cm) and reducing fishing mortality to a sustainable level (F = M) would sustain a healthy stock biomass. [ABSTRACT FROM AUTHOR]

Coregonus populations across their Holarctic range have often undergone unexplained collapses. Here, we document causes of collapse for two of the largest Coregonus populations in the world, cisco (C. artedi) in Green Bay, Lake Michigan, and Saginaw Bay, Lake Huron, during the 1950s. We used simulation models, rank‐order correlations, and historical literature to evaluate effects of overfishing, interactions with introduced rainbow smelt (Osmerus mordax), and overwinter bottom hypoxia on both cisco populations. Fully selected exploitation rates for cisco were alarmingly high (0.82–0.84), correlations and anecdotal evidence suggested negative interactions with rainbow smelt, and extensive areas of hypoxia coincident with cisco declines suggested incubation of cisco embryos was impaired regionally. Our findings suggested that negative effects of rainbow smelt were mainly responsible for the cisco population collapse in Green Bay and that overfishing and hypoxia had suppressed the Saginaw Bay cisco population before rainbow smelt caused its final collapse. [ABSTRACT FROM AUTHOR]

Across the globe, fish stocks have been in decline due to industrialization of fisheries resources, overfishing, pollution, and climate change, thereby warranting more fisheries assessments. The floodplain fishery of Tonle Sap Lake near the Kampong Khleang stilted community in the Chamkar Youn village in Cambodia was evaluated by: (1) characterizing fish assemblage structure and function, (2) highlighting temporal differences in fish assemblage, and (3) assessing potential indicators of fishing‐down‐the‐food‐web by the fishery. Fish trap data from the wet season were used to characterize fish abundance, diversity, species richness, and functional feeding guilds from fish catches in 2014 and 2019. Fish abundance declined 62% and species richness declined between 2014 and 2019. Smaller‐bodied, lower‐trophic level fishes dominated the catch. Our limited findings add insight into the status of a globally important fishery and highlight the need for more local collaborative fishery assessments. [ABSTRACT FROM AUTHOR]

Recovery of many seal populations has intensified seal‐fishery conflicts. Acoustic deterrent devices (ADDs), designed to deter seals while minimising collateral harm, provide a potential solution. We investigated feasibility of ADDs to protect a European whitefish (Coregonus lavaretus) fishery in the River Iijoki, Finland, which enters the Baltic Sea. A sound barrier produced by a line of ADDs across the river efficiently prevented grey (Halichoerus grypus) and ringed (Pusa hispida) seals from passing the barrier line, thereby increasing catches, decreasing damage to fishing gear and catch and resulting in fewer seal sightings in the area safeguarded by ADDs. Hence, blocking access of seals to a river or its section by ADDs during a critical fishing period is a promising method for reducing seal‐induced catch losses. However, long‐term assessments of impacts of ADDs are still needed to verify the overall effectiveness. [ABSTRACT FROM AUTHOR]

In real-world situations, marine fish farms accommodate multiple fish species and cohorts within the farm, leading to diverse farm layouts influenced by cage dimensions, configurations, and intricate arrangements. These cage management practices are essential to meet production demands, however, farm-level complexities can impact model predictions of waste deposition and benthic impact near fish cages. This is of particular importance when the cages are used for integrated multi-trophic aquaculture (IMTA) with benthic feeders, where this waste not only affects environmental conditions but also provides a potential food source. The Cage Aquaculture Particulate Output and Transport (CAPOT) model incorporated multiple species, cohorts, and cage arrangements to estimate waste distribution from a commercial fish farm in the Mediterranean between October 2018 and July 2019. This spreadsheet model estimated dispersion for individual fish cages using a grid resolution of 5 m x 5 m. The study categorized discrete production periods for each fish cage every month, aligning with intermittent changes in biomass and food inputs due to different cage management practices throughout production. This approach facilitated the use of detailed input data and enhanced model representativeness by considering variations in cage biomass, food types, settling velocities, and configurations. Model outputs, represented in contour plots, indicated higher deposition directly below fish cages that varied monthly throughout fish production cycles. Deposition footprints reflected changes in cage biomass, food inputs, and farm-level practices reflecting this real-world scenario where aquaculture does not follow a production continuum. Moreover, cohort dynamics and cage movements associated with the cage management practices of the fish farm influenced the quantity and fate of wastes distributed around fish cages, revealing variability in deposition footprints. Clearly, these findings have important implications for the design of benthic IMTA systems, with species such as sea cucumber and polychaetes. Variability in waste deposition creates challenges in identifying where the benthic organisms should be placed to allow optimal uptake of waste to meet their food requirements and increase survivability. Evidently, models have an important role to play and this study emphasizes the need for representative input data to describe actual food inputs, cage biomass changes, and management practices for more representative farm-scale modelling and essentially to improve particulate waste management. To effectively mitigate benthic impacts through IMTA, models must quantify and resolve particulate waste distribution and impact around fish farms to maintain a balanced system with net removal of wastes. Resolving farm-level complexities provides vital information about the variability of food availability and quality for extractive organisms that helps improve recycling of organic wastes in integrated systems, demanding a more representative modelling approach. [ABSTRACT FROM AUTHOR]

Decadal-scale oceanographic, environmental, and ecological changes have been reported in the Salish Sea, an ecologically productive and biodiverse inland sea in the northeast Pacific that supports the economies and cultures of millions of people; however, there are substantial observational gaps pertaining to physical water properties that make linkages between physical drivers and ecosystem effects difficult to ascertain. With the aim of addressing these gaps, we present the Hindcast of the Salish Sea (HOTSSea) v1 with temporal coverage from 1980–2018, developed using the NEMO ocean engine. An inter-model comparison and preliminary evaluation was performed to assess sensitivity to different atmospheric and ocean reanalysis products used for boundary forcings. Biases inherited from forcings were quantified and the effectiveness of a simple temperature bias correction factor applied at one ocean boundary was evaluated. Evaluation of salinity and temperature indicates performance is best in the Strait of Georgia where the model simulates temperature anomalies and a secular warming trend over the entire water column in general agreement with observations. Analyses of modelled ocean temperature trends throughout the northern and central part of the domain where model skill was high and where observations are relatively sparse yielded fresh insights, including that ocean temperature trends are spatially and temporally variable. HOTSSea v1 will support development of an end-to-end spatial-temporal ecosystem model for the Strait of Georgia and has potential for other research and management applications related to decadal-scale climate effects on marine ecosystems, fish, and fisheries. [ABSTRACT FROM AUTHOR]

Zooplankton are the key intermediary between primary production and the fish community and a cornerstone of marine food webs, but they are often poorly represented in models that tend to focus on fish, charismatic top predators, or ocean biogeochemistry. In this study, we use an intermediate complexity end‐to‐end food web model of the North Sea with explicit two‐way coupling of zooplankton to phytoplankton and higher trophic levels to ask whether this matters. We vary the metabolic rate of omnivorous zooplankton (OZ) as a proxy for uncertainties in our understanding and modeling of zooplankton form and function, and moving beyond previous studies we look at the impacts on the food web in concert with climate warming and fishing. We consider impacts on food web state and time to recover the relevant unfished state after fishing ceases. We also consider potential impacts on pelagic and demersal fishing fleets if we assume that they are constrained by the requirement to allow recovery to an unfished state within a certain period of time as a way of ensuring consistency with Good Environmental Status as required by EU and UK legislation. We find that all three aspects considered are highly sensitive to changes in the treatment of zooplankton, with impacts being larger than for warming of 2 or 4°C across most food web functional groups, particularly for apex predators. We call for a programme of research aimed at improving our understanding of zooplankton ecology and its relationship to the wider food web, and we recommend that improved representations of zooplankton are incorporated in future modeling studies as a priority. [ABSTRACT FROM AUTHOR]

The grey rockcod, Lepidonotothen squamifrons is an important prey species for seals, penguins and Patagonian toothfish (Dissostichus eleginoides) in the Southern Ocean. Across the Kerguelen Plateau, the species was fished to commercial extinction (ca. 152 000 tonnes between 1971 and 1978) prior to the declaration of the French Exclusive Economic Zone in 1979 and the Australian Fishing Zone in 1981. In this study we estimate; age, growth, maturity, sex ratio, body condition (weight-at-length), and population density of grey rockcod using data from 19 trawl surveys from 1990 to 2014. There appeared to be three distinct geographical populations, with differences in biological parameters within each population. This study has identified separate metapopulations within the southern region of the Kerguelen Plateau and we recommend that management should take into account the different characteristics of these populations, and that this meta-population structure may be a factor in why this species required several decades to show signs of recovery. [ABSTRACT FROM AUTHOR]

Individuals must reproduce to survive and thrive from generation to generation. In fish, the fecundity of individuals and estimates of total reproductive output are critical for evaluating reproductive success and understanding population dynamics. Estimating fecundity is an onerous task; therefore, many populations lack contemporary estimates of fecundity and size‐fecundity relationships. However, reproductive dynamics are not static in time; therefore, it is important to develop contemporary fecundity estimates to better inform conservation and management action. To highlight the importance of contemporary fecundity estimates, we examined the fecundity of southern Gulf of St. Lawrence (sGSL) spring and fall spawning Atlantic herring in 2022, developed size‐fecundity models, and compared these to historical fecundity estimates and models. Our results suggest that the average fecundity of sGSL spring and fall herring has undergone a substantial temporal decline of approximately 47% and 58%, respectively, since the 1970s and 1980s. The size‐fecundity relationships for fall spawning herring have shifted, with fish of a given size exhibiting lower fecundity in 2022 compared to the 1970s. Alternatively, the size‐fecundity relationships for spring spawning herring have remained relatively static. Furthermore, simulations highlighted a substantial reduction in potential reproductive output in 2022 compared to 1970 of approximately 32% and 68% for spring and fall spawners, respectively, based on a fixed number of mature females, which may have negative implications for stock rebuilding. Overall, our study provides support for periodic estimates of fecundity in fish populations to better understand temporal changes in reproductive and population dynamics. [ABSTRACT FROM AUTHOR]

Neglected cryptic diversity can lead to the permanent loss of locally adapted alleles, which can reduce resilience to rapid environmental change. It can also result in overestimation of fisheries stock sizes that can result from treating different species as if they belonged to one. Bluefish (Pomatomus saltatrix) is considered a circumtropical and subtropical species and an important fishery resource all over the world. Differences in ecologically relevant traits are observed among isolated populations. Also, in the Southwestern Atlantic, molecular data suggest multiple populations, but these are treated as a single fish stock by regulatory agencies due to a lack of definitive information. We used whole mitogenome sequences, nuclear (rho) and mitochondrial (coxI and cytb) genes, as well as microsatellites to investigate historical and current genetic population structure and parameters of bluefish in the Western Atlantic. A total of 263 samples were collected along the Brazilian coast and in the USA (New Jersey, Northwest Atlantic). Data revealed the existence of two evolutionarily significant units (ESU) of bluefish along the South American coast, later confirmed by whole mitogenome sequencing of both haplogroups. These two ESUs have a mostly parapatric distribution, with some areas of overlap, which vary along the year. We also conducted seasonal sampling in Brazil to investigate migration patterns. ESUs occur mostly north and south of parallel 23° 40′ S, with an overlap area that varied seasonally. The level of differentiation between those two ESUs in the SW Atlantic, even in sympatry, is as high as that found between them and those from the NW Atlantic and Europe. Parapatric distribution and restricted gene flow suggest the existence of ecological barriers and local adaptation. The splitting of an ancient population from the Southwestern Atlantic into two putative species is important to understand bluefish evolutionary diversification and has implications for fishery regulatory measures in Brazil. [ABSTRACT FROM AUTHOR]

Acoustic methods are often used for fisheries resource surveys to investigate fish stocks in a wide area. Commercial fisheries echo sounders, which are installed on most small fishing vessels, are used to record a large amount of data during fishing trips. Therefore, it can be used to collect the basic information necessary for stock assessment for a wide area and frequently. To carry out the quantification for the fisheries echo sounder, we devised a simple method using the backscattering strength of the seabed to perform calibration periodically and easily. In this study, seabed secondary reflections were used instead of primary reflection because the fisheries echo sounders were not equipped with a time-varied gain (TVG) function, and the primary backscattering strength of the seabed was saturated. It was also necessary to use standard values of seabed backscattering strength averaged over a certain area for calibration to eliminate some of the effects of differences in seabed sediment and vessel motions. By using standard values of the seabed secondary reflections, the fisheries echo sounder was calibrated accurately. Our study can provide a reliable framework to calibrate commercial fisheries echo sounders, to improve the estimation and management of fishery resources. [ABSTRACT FROM AUTHOR]

For management efforts to succeed in Caribbean fisheries, local fishers must support and be willing to comply with fishing regulations. This is more likely when fishers are included in a stock assessment process that utilizes robust scientific evidence, collected in collaboration with fishers, to evaluate the health of fish stocks. Caribbean parrotfishes are important contributors to coral reef ecosystem health while also contributing to local fisheries. Scientifically robust stock assessments require regional species-specific information on age-based key life history parameters, derived from fish age estimates. Evaluation of the accuracy of age estimation methods for fish species is a critical initial step in managing species for long-term sustainable harvest. The current study resulted from a collaborative research program between fish biologists and local fishers investigating age, growth, and reproductive biology of the seven parrotfish species landed in U.S. Caribbean fisheries; specifically, we validated age estimation for stoplight parrotfish Sparisoma viride and queen parrotfish Scarus vetula. This is the first study to directly validate age estimation for any parrotfish species through analysis of Δ14C from eye lens cores. Our age estimation validation results show that enumeration of opaque zones from thin sections of sagittal otoliths for a Sparisoma and a Scarus species provides accurate age estimates. The oldest stoplight parrotfish and queen parrotfish in the Δ14C age estimation validation series were 14 y and 16 y; while the oldest stoplight parrotfish and queen parrotfish we aged to-date using the Δ14C validated age estimation method were 20 y and 21 y, respectively. Fish longevity (maximum age attained/life span) is a key life history parameter used for estimation of natural mortality, survivorship, and lifetime reproductive output. Past reviews on parrotfishes from the Pacific and Atlantic concluded that most Caribbean/western Atlantic parrotfish species are relatively short-lived with estimated maximum ages ranging from 3–9 y. However, information from our collaborative research in the U.S. Caribbean combined with recently published age estimates for Brazilian parrotfish species indicate that many western Atlantic parrotfishes are relatively long-lived with several species attaining maximum ages in excess of 20 y. [ABSTRACT FROM AUTHOR]

Many management and conservation contexts can benefit from understanding relationships between species abundances, which can be used to improve predictions of species occurrence and abundance. We present conditional prediction as a tool to capture information about species abundances via residual covariance between species. From a fitted joint species distribution model, this framework produces a species coefficient matrix that contains relationships between species abundances. The species coefficients allow co‐observed species to be treated as a second set of predictors supplementing covariates in the model to improve prediction. We use simulations to demonstrate the potential benefits and limitations of conditional prediction across data types and species covariance before applying conditional prediction to two management contexts with real data. Simulations demonstrate that conditional prediction provides the largest benefits to continuous data and when there is residual covariance between many species. In our first application, we show that conditioning on other species improves in‐sample and out‐of‐sample predictions of fish and invertebrate species, including Atlantic cod. In our second application, we show that the species coefficient matrix can be used to identify bird species at risk of nest parasitism by Brown‐headed Cowbirds. Synthesis and applications. We present guidelines for using conditional prediction, which can help understand relationships between species abundances, improve predictions and inform conservation in a variety of contexts. [ABSTRACT FROM AUTHOR]

The study of morphological characteristics and growth information in fish scales is a crucial component of modern fishery biological research, while it has been less studied in fossil materials. This paper presents a detailed morphological description and growth analysis of a fossil ctenoid scale obtained from the Upper Cretaceous Campanian lacustrine deposits in northeastern China. The morphological features of this fossil scale are well-preserved and consistent with the structures found in ctenoid scales of extant fish species and display prominent ring ornamentation radiating outward from the central focus, with grooves intersecting the rings. A comparative analysis of the morphological characteristics between the fossil ctenoid scale and those well-studied extant fish Mugilidae allows us to explore the applicability of modern fishery biological research methods to the field of fossil scales. The scale length, scale width, the vertical distance from the focus to the apex of the scale, and the total number of radii have been measured. The age of the fish that possessed this ctenoid scale has been estimated by carefully counting the annuli, suggesting an age equal to or more than seven years. The distribution of growth rings on the scale potentially reflects the warm paleoclimatic condition and fish-friendly paleoenvironment prevalent during that period. This paper, moreover, serves as a notable application of fishery biological methods in the examination of fossil materials. [ABSTRACT FROM AUTHOR]

The Covid‐19 lockdown in India in March 2020 revealed the presence of Adivasi communities in the marine fishing industry of Goa, a coastal state in India. While the migration for work of Adivasi communities from the central regions of the country is well recorded, their movement across geographies of the forest and the coast is relatively unknown. Working with initial data collected during the lockdown, interviews conducted after the pandemic and using secondary materials, the paper sought to understand the social and material conditions in the forest and the coastal regions that shape this movement. Centring the waged relation of Adivasi workers opened the door to thinking about the marine fishing sector in India as a capitalist industry, while paying attention to social reproduction highlighted how the coastal and forest regions are spatially linked through their movement and labour. This highlights that the coasts and forests are going through distinct processes of capitalist intensification and expansion. Making connections between ecological appropriation, historical processes of resource extraction and marginalization, the paper finds that the extraction of fish resources in Goa is made productive through the hierarchization and differentiation of Adivasi workers. It reveals how the social relations of identity and caste mediate access to and define conditions of work at sea. [ABSTRACT FROM AUTHOR]

How to manage harvest under great uncertainty is a fundamental question for many wildlife managers, particularly when resources necessary to estimate abundance or population trends are limited. The large Newfoundland and Labrador murre hunt is the only licensed harvest of seabirds in Canada. Though harvest of thick‐billed murres (Uria lomvia) and common murres (Uria aalge) has declined considerably since the 1960−1970s from >500,000 birds taken annually to approximately 100,000 annually in recent years, potential murre colony declines across the North Atlantic have again triggered concerns over the sustainability of murre harvest in Canada. The effect of current harvest is difficult to assess because there is considerable uncertainty in recent population size, trend, demographic rates, licensed harvest, fisheries bycatch, and illegal harvest. To assess the situation, we simulated the population size necessary to sustain current levels of approximated anthropogenic mortality using a potential biological removal approach, which simplifies and constrains population processes to a few key variables. Based on these simulations, the Canadian licensed harvest of thick‐billed murre is consistent with conservation management objectives, as is common murre licensed harvest and fisheries bycatch. Adding estimated illegal harvest resulted in unstainable mortality levels in both species. While wildlife managers will need to formally assess the relative costs and benefits of reducing uncertainty in this system through improved harvest and population monitoring, illegal harvest and commercialization need to be addressed to manage Canadian murre populations. Potential biological removal approaches can be a useful framework to assess harvest management decisions for marine birds and other data‐limited species. [ABSTRACT FROM AUTHOR]

The greater amberjack Seriola dumerili is economically important in both capture fisheries and aquaculture. It is a gonochoristic species with no noticeable sexual dimorphism, usually reaching maturity at 3–4 years. Spawning occurs in the Pacific from May to June but varies between regions. During a study on the maturity of greater amberjack, abnormal hermaphrodites (AH) with ovotestes were found. Of the 51 fish examined from June 2017 to April 2018, 2 individuals (3.9%) were classified as AH, with one each identified in February and April 2018. These AHs were larger than the gonochoristic (GC) individuals of the same age. In February, both AH and GCs had sperm-filled seminal lobules and ovaries at the primary yolk stage. By April, atresias were seen in both the AHs and GCs. While oocyte diameter increased in both AHs and GCs between February and April, the gonadosomatic index was lower in AHs. Plasma estradiol-17β and 11-ketotestosterone levels of AHs were similar to those of male GCs. These results suggest that AHs have accelerated growth with potential maturation as functional males. This is the first report on hermaphroditism in the Seriola genus. [ABSTRACT FROM AUTHOR]

The accuracy of the back-calculation method to estimate past individual growth based on the relationship between otoliths and body length is important. However, limited studies have examined the variation in accuracy by measurement site used for estimation, and little has been done to evaluate its effectiveness. Currently, effective utilization of juvenile fish in the blackthroat seaperch fishery in the Sea of Japan does not always take place, so it is necessary to investigate the complex relationship between population density and growth rate. This study estimates body length and weight from otolith length, weight, and area of blackthroat seaperch, analyzes variations in estimation accuracy at each measurement site, and provides a general quantitative protocol for evaluating the performance of each measurement site. The conversion models for body length and body weight indicate that models using otolith weight and area are more accurate than those using otolith length. There were no significant differences in the estimation accuracy of these models, and the estimation errors were all less than 0.7% of the original body length and weight means. Searching for the best model, verifying the estimation accuracy quantitatively, and selecting the model to use is important when performing back-calculations. [ABSTRACT FROM AUTHOR]

As taxonomic studies revise our understanding of biodiversity, both fisheries managers and the angling public must adapt to best conserve fisheries. Unfortunately, communication gaps between scientists and anglers may result in lags and inaccuracies in the taxonomic information available to anglers. We updated the International Game Fish Association (IGFA)'s black bass Micropterus spp. world records to current taxonomic consensus. Seven new species were acknowledged for all‐tackle world record availability, and four of seven existing species records were revised. Florida Bass M. salmoides (formerly M. floridanus), Neosho Bass M. velox, and four members of the Redeye Bass species complex (M. cahabae, M. chattahoochae, M. tallapoosae, and M. warriorensis) are now recognized. Additionally, Alabama Bass M. henshalli—an emerging invasive species—is now distinguished from the smaller, broadly distributed Spotted Bass M. punctulatus. A misidentified specimen resulted in vacant all‐tackle records for Shoal Bass M. cataractae and Redeye Bass M. coosae. Genetic verification is warranted in the future, but implementation may create accessibility barriers to record submissions. We hope these efforts will encourage anglers to learn more about black bass diversity, to pursue their own world record catches, and to gain awareness of the conservation challenges threatening this iconic group. [ABSTRACT FROM AUTHOR]

Climate change and industrial fishing have profound effects on marine ecosystems. Numerical models that capture key features of fish biomass dynamics and its interaction with fishing can help assess the biogeochemical and socio-economic consequences of these impacts. However, these models have significant biases and do not include many processes known to be relevant. Here we describe an updated version of the BiOeconomic mArine Trophic Size-spectrum (BOATS) model for global fish and fisheries studies. The model incorporates new ecological and economic features designed to ameliorate prior biases. Recent improvements include reduction of fish growth rates in iron-limited high-nutrient low-chlorophyll regions, and the ability to simulate fisheries management. Novel features described here include a separation of pelagic and demersal fish communities to provide an expanded representation of ecological diversity, and spatially variable fishing costs and catchability for more realistic fishing effort dynamics. We also introduce a new set of observational diagnostics designed to evaluate the model beyond the boundary of large marine ecosystems. Following a multi-step parameter selection, the updated BOATSv2 model shows comparable performance to the original model in coastal ecosystems, accurately simulating catch, biomass and fishing effort. The revised model provides a markedly improved representation of fisheries in the High Seas, largely correcting the biases of the original version, including excessive high-sea catches and too rapid deepening of fishing effort over time. The updated model code is available for simulating both historical and future scenarios. [ABSTRACT FROM AUTHOR]

Despite progress in the management of assessed fish populations, many countries lag behind international commitments to restore overexploited stocks to healthy abundances. Here we use a mixed‐methods positive deviance approach, also known as 'bright spot' analysis, to understand what drives the successful governance of exploited species by learning from positive outliers, or 'deviants'. We use Canada as a case study, identifying factors driving the abundance of 230 commercially exploited fish and invertebrate populations, of which only 28% were classified at healthy abundance in 2022. We first applied a generalized linear model to test how diverse socio‐ecological fishery attributes relate to stock health. We found healthier stocks are positively and significantly correlated with certain management regions, more selective gears, eco‐certification, and high fishery value. Counterintuitively, healthier stocks were also associated with high inherent fishing vulnerability and the absence of reference points. We then used fishery expert surveys and interviews to investigate the social and institutional characteristics of stocks healthier than expected, given their circumstances. We found that fisheries targeting these positive outliers have lower conflict among users, balanced stakeholder involvement in data collection and decision‐making, and improved accounting of mortality sources. Lessons from these positive deviants can be applied to improve underperforming management systems that are struggling to reverse overexploitation in Canada and elsewhere. More generally, we suggest that a positive deviance approach, already used in public health, could be a promising tool to learn about successful fisheries management interventions, and the diverse actors responsible for ensuring these interventions are successful. [ABSTRACT FROM AUTHOR]

Despite continued calls for the application of ecosystem‐based fisheries management, tactical fisheries management continues to be heavily reliant on single‐species stock assessments. These stock assessments rarely quantitatively integrate the effects of ecosystem processes on fish stock productivity. This lack of integration is ultimately driven by the complexity of interactions between populations, ecosystems and fisheries, which produces uncertainty when defining which processes to include and how to include them. Models developed using a structured hypothesis testing framework would allow formalizing uncertainties while underscoring the importance of incorporating different population and ecosystem processes to explain non‐stationary stock productivity. Here, we develop a conceptual framework for extending and comparing population dynamics models of increasing complexity. We illustrate the utility of the framework by investigating the population and ecosystem processes that most likely affected the differential recovery of two flatfish populations (American plaice and yellowtail flounder) on the Newfoundland Grand Banks over the past three decades. We found that yellowtail flounder population dynamics were primarily driven by recruitment variability, which was negatively affected by warmer climatological conditions, as indicated by an integrated regional climate index. Meanwhile, American plaice population dynamics were affected by a combination of temporal variability in recruitment and natural mortality, where natural mortality increased during colder than average conditions. By exploring hypotheses about the effects of population and ecosystem processes on population dynamics, this modelling framework will improve understanding about the drivers of shifts in population productivity while serving as a transparent and robust approach to support ecosystem‐based fisheries management. [ABSTRACT FROM AUTHOR]

This paper presents an agenda for the future of gender research in small‐scale fisheries (SSF). Building on expert insight from scholars who gathered during the 4th World Small‐Scale Fisheries Congress Africa (4WSFC) with a synthesis of existing literature, we identify six topics that warrant future investigation in SSF, along with methodological considerations for addressing them. Research priorities include identifying pathways towards (1) equitable participation in governance and decision‐making, (2) valuing all actors' contributions to aquatic food systems, (3) increasing access to financial services, (4) inclusive infrastructural development, (5) livelihood diversification and (6) reducing occupational health hazards. Several important methodological considerations include (i) using multiple methodologies, (ii) applying participatory methods, (iii) collecting gender‐disaggregated data, (iv) integrating gender into a food systems approach in fisheries, (v) engaging an intersectional approach and (vi) operationalising equity. [ABSTRACT FROM AUTHOR]

Fish oil by-product (FOB) recovered from the precooking process in the cannery industry and the pressing process in fish meal production are potential resources. However, this fish oil still needs a refinery process to improve the quality of fish oil. This study aimed to identify the physicochemical characteristics of the initial fish oil by-product, the physicochemical profiles, and fatty acids of the fish oil by-product after degumming neutralization and bleaching (bentonite, zeolite, and carbon adsorbents) processes from the cannery and fish meal industry. Results showed the initial physicochemical characteristics of fish oil waste from fish flour have lower quality than canned products (acid value, free fatty acids, PV, AV, TOTOX value, viscosity, and refractive index) but are inversely proportional to the iodine value. Results showed degumming (D) and neutralization (N) processes from the Fish oil canning process (FCP) and Fish oil meal process (FMP) could improve the quality parameters of fish oil by-products by reducing the acid value (7.90, 0.65, 9.17, 0.58 mg KOH/g), respectively; free fatty acid (3.97, 0.33, 4.60, 0.29 % oleic) respectively; peroxide value (PV) (15.18, 7.38, 17.64, 7.10 mEq/kg), respectively; anisidine value (AV) (14.36, 6.61, 14.64, 6.51) respectively; total oxidation (TOTOX) value (44.72, 21.37, 49.64, 20.71) respectively; and iodine (167, 153, 163, 155 mg/100 g), respectively as well as increasing the lightness (23.80, 25.70, 20.65, 26.00), respectively. In the bleaching process (B), zeolite (15 %) was an effective adsorbent to obtain oil with the best quality parameters due to zeolite possessed greater polarity and surface area at a higher concentration, which resulted in the acid value for FCP and FMP (0.26, 0.22 mg KOH/g); free fatty acid (0.13, 0.15 % oleic); PV (2.44, 5.71 mEq/kg); AV (2.5, 4.9); TOTOX value (7.16, 9.11); and iodine (138, 151 mg/100 g) as well as increasing the lightness (37.08, 36.74) that are appropriate to International Fishmeal & Oil Manufacturers Association (IFOMA), Codex Alimentarius Committee (CAC), and International Fish Oils Standards (IFOS) standards (p < 0.05). All adsorbents effectively increase the brightness of the FOB. The higher the concentration of adsorbents, the higher the clarity of the FOB. For zeolite absorbents, there was an increase of 16.73 - 32.3 % for FCP and 15.39 - 32.69 % for FMP, but the viscosity decreased with a range of 24.50 - 36.50 cPs. FCP contains 14 fatty acids, while FMP contains 12 fatty acids. The number of SFA and MUFA detected in FCP is lower than in FMP. In contrast, the amount of PUFA in FCP is relatively higher than in FMP. The percentage of EPA and DHA in FCP is lower than in FMP. Overall, the refining process affects the fatty acid composition of fish oil by-products both in the canning process and in fish meal. [ABSTRACT FROM AUTHOR]

Open data that can be easily incorporated into analyses are essential for developing ecosystem approaches to marine ecological management: a common goal in fisheries policy in many countries. Although it is not always clear what constitutes an ecosystem approach, it always involves scientists working with a large variety of data and information, including data from physical and oceanographic sampling, multispecies surveys, and other sources describing human pressures. This can be problematic for analysts because these data, even when available, are often held in disparate datasets that do not necessarily correspond at appropriate temporal and spatial scales. Data can often only be obtained by specific requests to individuals in governmental agencies who are delivering on an increasing number of data requests as interest grows in practical ecosystem approach implementation. This data access model is not sustainable and hinders the momentum for ecosystem approach development. We describe a data bundling R package that makes data and climate projections available at appropriate scales to facilitate development of an ecosystem approach for the Gulf of St. Lawrence, Canada. This approach integrates closely with the present workflow of most government analysts, academics in fisheries, and scientists in private industry. The approach conforms with open data initiatives and makes data easily available globally while relieving some of the burden of data provision that can fall to some individuals in government laboratories. The structure and approach are generic, adaptable, and transferable to other regions and jurisdictions. [ABSTRACT FROM AUTHOR]