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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]

The American eel (Anguilla rostrata) has long been regarded as a panmictic fish and has been confirmed as such in the northern part of its range. In this paper, we tested for the first time whether panmixia extends to the tropical range of the species. To do so, we first assembled a reference genome (975 Mbp, 19 chromosomes) combining long (PacBio and Nanopore and short (Illumina paired‐end) reads technologies to support both this study and future research. To test for population structure, we estimated genotype likelihoods from low‐coverage whole‐genome sequencing of 460 American eels, collected at 21 sampling sites (in seven geographic regions) ranging from Canada to Trinidad and Tobago. We estimated genetic distance between regions, performed ADMIXTURE‐like clustering analysis and multivariate analysis, and found no evidence of population structure, thus confirming that panmixia extends to the tropical range of the species. In addition, two genomic regions with putative inversions were observed, both geographically widespread and present at similar frequencies in all regions. We discuss the implications of lack of genetic population structure for the species. Our results are key for the future genomic research in the American eel and the implementation of conservation measures throughout its geographic range. Additionally, our results can be applied to fisheries management and aquaculture of the species. [ABSTRACT FROM AUTHOR]

Similar to many freshwater ecosystems, the Laurentian Great Lakes of North America have undergone numerous anthropogenic stressors resulting in considerable loss of biodiversity and habitat. Among Great Lakes fishes, the coregonine sub-family has endured the most extensive declines, including extinction of several species (Coregonus johannae, C. alpenae, and C. kiyi orientalis) and at least 10 instances of local extirpations of other species (C. nigripinnis, C. reighardi, C. zenithicus, C. hoyi, and C. artedi) across all 5 lakes, much of which occurred prior to the 1960s owing to overfishing, interactions with non-indigenous species, and habitat loss. Despite these declines, no federal-, provincial-, or state-mandated actions were ever implemented to conserve coregonine diversity, potentially because so much of the coregonine declines occurred prior to the enactment of federal conservation legislation. Possible explanations for inaction since enactment of that legislation include insufficient data on biological vulnerability or threats, unresolved taxonomy, and limited support from the fishery management agencies and their stakeholders prior to the 2000s. In recent decades, however, several fishery management agencies have undertaken efforts to re-introduce coregonine diversity. These efforts helped lead to development of a science-based framework to restore coregonines that was universally endorsed by fishery managers representing eight U.S. states, four U.S. tribal organizations, and the province of ON, Canada, in May 2018. The basin-wide framework is based on principles of conservation biology and adaptive management. We describe details of its key steps, including planning, restoring, and evaluating, while also describing recent implementation efforts to develop methods, improve available resources, and enhance coordination across the basin. Although our paper describes a regional effort to restore native coregonines, our adaptive-management approach could be used by other multi-agency stakeholders seeking to conserve or restore native fishes. [ABSTRACT FROM AUTHOR]

Accumulating evidence has demonstrated a decrease in post-release survival of angled Atlantic salmon (Salmo salar) during periods of warm water temperatures. Consequently, the application of water temperature-related fishery closures by resource managers is gaining interest. Here, the role of water temperature-related fishery closures in recreational Atlantic salmon fisheries is reviewed by (1) presenting a synopsis of factors that could influence the effectiveness of these fishery closures, (2) using novel fisheries and water temperature data from Eastern Canada, to illustrate how various closures can affect management outcomes, and (3) discussing alternative options for managers to implement such fishery closures. Results suggest there are a number of considerations when implementing a water temperature-related fishery closure. For populations meeting conservation requirements, results show that additional angling opportunities can occur at minimal conservation cost by applying morning-angling-only protocols in rivers during periods of reduced catch and release and moderately warm water temperatures. The impact on salmon populations, however, will be higher in situations where high catch and release rates overlap with warm water periods (e.g. when day-night water temperatures remain in excess of 20 °C or remain high during the summer) or occur over prolonged periods of extreme warm water temperatures. In situations where resource managers have few resources and need to implement water temperature-related fishery closures on a large spatial scale, it is recommended that strategically chosen index rivers to inform water temperature-related fishery closures are used. In rivers with healthy salmon populations, angling opportunities during periods of warm water could be considered if supported by enhanced monitoring (e.g., monitoring salmon abundance, spatially-structured water temperature data, and mandatory catch reporting (catch and effort)) that optimize tradeoffs between socio-economic benefits and conservation. [ABSTRACT FROM AUTHOR]

Twenty-six years ago, in response to regionally devastating fisheries collapses in Canada, Hutchings et al. asked "Is scientific inquiry incompatible with government information control?" Now, a quarter-century later, we review how government science advice continues to be influenced by non-science interests, particularly those with a financial stake in the outcome of the advice. We use the example of salmon aquaculture in British Columbia, Canada, to demonstrate how science advice from Fisheries and Oceans Canada (DFO) can fail to be impartial, evidence-based, transparent, and independently reviewed—four widely implemented standards of robust science advice. Consequently, DFO's policies are not always supported by the best available science. These observations are particularly important in the context of DFO having struggled to sustainably manage Canada's marine resources, creating socio-economic uncertainty and putting the country's international reputation at risk as it lags behind its peers. We conclude by reiterating Hutchings et al.'s unheeded recommendation for a truly independent fisheries-science advisory body in Canada to be enshrined in the decision-making process. [ABSTRACT FROM AUTHOR]

The Atlantic Zone Monitoring Program (AZMP) was established by Fisheries and Oceans Canada (DFO) in 1998 with the aim of monitoring physical and biological ocean conditions in Atlantic Canada in support of fisheries management. Since 2014, at least two of the carbonate parameters (pH; total alkalinity, TA; and dissolved inorganic carbon, DIC) have also been systematically measured as part of the AZMP, enabling the calculation of derived parameters (e.g., carbonate saturation states, Ω , and partial pressure of CO2 , p CO2). The present study gives an overview of the spatiotemporal variability in these parameters between 2014 and 2022. Results show that the variability in the carbonate system reflects changes in both physical (e.g., temperature and salinity) and biological (e.g., plankton photosynthesis and respiration) parameters. For example, most of the region undergoes a seasonal warming and freshening. While the former will tend to increase Ω , the latter will decrease both TA and Ω. Spring and summer plankton blooms decrease DIC near the surface and then remineralize and increase DIC at depth in the fall. The lowest p CO2 values (down to ∼ 200 µ atm) are located in the cold coastal Labrador Current, whereas the highest values (>1500 µ atm) are found in the fresh waters of the Gulf of St. Lawrence and the St. Lawrence Estuary. The latter is also host to the lowest pH values of the zone (7.48 in the fall of 2022). Finally, most of the bottom waters of the Gulf of St. Lawrence (>90 %) are undersaturated with respect to aragonite (Ωarg<1). In addition to providing a baseline of carbonate parameters for the Atlantic Zone as a whole, this comprehensive overview is a necessary and useful contribution for the modelling community and for more in-depth studies. The full dataset of measured and derived parameters is available from the Federated Research Data Repository: 10.20383/102.0673. [ABSTRACT FROM AUTHOR]

Environmental DNA (eDNA) monitoring methods have played a significant role in improving fisheries management decisions. Yet, their impact to date has been rather limited in Canada, where eDNA sampling and analyses are only beginning to be used to inform management and conservation decisions, practices, and policies. Studies investigating hurdles to the incorporation of eDNA evidence into fisheries management decisions generally focus on technical challenges (i.e., risks of false-positive and false-negative detections). We set out to identify challenges that eDNA researchers and conservation practitioners must overcome to fully unlock the benefits of eDNA sampling for fish management in the Canadian context. We discuss aspects of the broad and heterogeneous geography, preponderance of regions located far from densely populated areas, complex political landscape, and cultural diversity of Canada that may complicate the design of reliable eDNA monitoring tools or restrict their use if not adequately addressed. To advocate for the wider use of eDNA sampling, we outline a number of action items that would facilitate the broad adoption of eDNA sampling as a monitoring tool at the Canadian scale. [ABSTRACT FROM AUTHOR]

Climate change will amplify stress on marine systems already challenged by conflicts and inequities relating to fisheries access, management decisions, and ocean uses across sectors. Understanding how those most connected to fisheries perceive the risks associated with climate change is critical to developing effective responses and establishing management priorities. Adaptation planning efforts may be hindered by perceptions of unequal or unfair distribution of resources and the processes in place to manage them. In contrast, adaptation planning that is more inclusive, transparent, and addresses social dimensions and perceptions of fisheries is more likely to garner support from fishers and fishing communities broadly. We elicited fisher perceptions of climate change impacts on fisheries, and responses to these impacts, through an online survey of commercial fishers in Canada's Pacific region. The survey highlights substantial concern for climate change, the impacts it will have on fishers' livelihoods and well-being, and some of the key challenges that may interfere with the ability of fishers and fisheries management to adapt. We frame the findings of the survey drawing from concepts of social justice, focusing on distributive and procedural justice, as necessary considerations, and context for climate change adaptation planning. Developing plans and processes to respond to climate change impacts on fisheries requires not only understanding ecological impacts and challenges, but also the social and institutional considerations that could help or hinder efforts to respond effectively and equitably to a changing ocean. [ABSTRACT FROM AUTHOR]

Understanding the influence of ocean conditions on predator–prey relationships can provide insight for ecosystem‐based fisheries management. Pacific hake (Merluccius productus) are abundant and commercially important groundfish in the California Current Ecosystem (CCE) that consume euphausiids (krill) as a major prey item. We used data from the biennial joint U.S.‐Canada Integrated Ecosystem & Acoustic Trawl Survey for Pacific hake (2007–2019, n = 8 surveys) to quantify co‐occurrence of age 2+ hake with krill in relation to bottom depth, continental shelf break location, surface chlorophyll‐a, and 100‐m temperature. Vertical distributions of hake varied among years and were not correlated to krill depth. Hake hotspots occurred primarily off the Oregon coast and near Cape Mendocino, while most krill hotspots occurred in the northern CCE. The probability of co‐occurrence was greatest during cool ocean conditions (100‐m temperature 1°C below average), averaging 41.0% and extending throughout most of the CCE. During warm ocean conditions (100‐m temperature 1°C above average), predicted co‐occurrence averaged 17.0% and was concentrated near Cape Mendocino. These results indicate that hake‐krill co‐occurrence is a function of predator and prey spatial distributions and overall krill abundance. Furthermore, temperature influences hake‐krill co‐occurrence and may explain some of the variation in hake growth and recruitment to the fishery. [ABSTRACT FROM AUTHOR]

Establishing long-term microbiome-based monitoring programs is critical for managing and conserving wild fish populations in response to climate change. In most cases, these studies have been conducted on gut and, to a lesser extent, skin (mucus) microbiomes. Here, we exploited the concept of liquid biopsy to study the circulating bacterial microbiome of two Northern halibut species of economic and ecological importance. Amplification and sequencing of the 16S rRNA gene were achieved using a single drop of blood fixed on FTA cards to identify the core blood microbiome of Atlantic and Greenland halibut populations inhabiting the Gulf of St. Lawrence, Canada. We provide evidence that the circulating microbiome DNA (cmDNA) is driven by genetic and environmental factors. More specifically, we found that the circulating microbiome signatures are species-specific and vary according to sex, size, temperature, condition factor, and geographical localization. Overall, our study provides a novel approach for detecting dysbiosis signatures and the risk of disease in wild fish populations for fisheries management, most notably in the context of climate change. [ABSTRACT FROM AUTHOR]

Knowledge of the larval ecology of winter‐spawning fish from the Estuary and Gulf of St. Lawrence, Canada, remains scarce due to the seasonal ice cover that prevents ichthyoplankton sampling using conventional methods. Two winter‐spawning species, Atlantic halibut (AH, Hippoglossus hippoglossus) and Greenland halibut (GH, Reinhardtius hippoglossoides), support the most important groundfish fisheries of this area. In March 2020, the authors captured 10 halibut larvae ranging in size from 5 to 14 mm during an opportunistic survey in the GSL onboard an icebreaking vessel. Of these, eight were AH and two GH. Judging by their very small size, the larvae were only a few days old, suggesting that the spawning grounds are close to the capture sites. This effort constitutes a first step in validating the putative spawning areas for these two important GSL stocks. This knowledge is important for the conservation and sustainable management of these fisheries. [ABSTRACT FROM AUTHOR]

Fisheries are complex social–ecological systems, meaning that the achievement of 'sustainable' fisheries demands a multifaceted approach, involving ecological, economic, social, and institutional dimensions. Addressing these diverse concerns requires the collection and synthesis of new sources of information by science-advising bodies and the engagement of multiple knowledge types from rightsholders and stakeholders. The 'modernized' (2019) Fisheries Act in Canada allows for a diverse range of considerations to form the basis of fisheries management decisions, including knowledge from community or industry groups, but it remains unclear where and when such information is available, how this information is prioritized, who contributes to information-gathering processes, and what the management consequences of information use might be. The present study uses a selection of science-advising documents and briefing notes for decision makers to explore the information and priorities informing fisheries management decisions in Atlantic Canada, with a focus on how rightsholders and stakeholders contribute to the process. These findings can inform efforts to adopt an inclusive and participatory approach to evidence-based decision making to achieve sustainable fisheries, in the broadest sense of the word. [ABSTRACT FROM AUTHOR]

The giant red sea cucumber (Apostichopus californicus) fishery in BC, Canada, is considered sustainable by managers but not by many harvesters. In 1997, the Kitasoo/Xai'xais First Nation began experimental fishing areas (EFAs) at Tolmie Channel and Laredo Inlet to test the effects of different exploitation rates on sea cucumber populations and determine what harvest levels are sustainable. These EFAs were annually surveyed by dive transects and subsequently harvested from 1998 to 2018. Bayesian surplus production models developed in 2011 indicated that the fishery was sustainable, after which the fishery changed from annual to 3-year rotational harvests. Here, we develop updated models to estimate the sustainability of the fishery using all currently available EFA data, including direct estimates of unfished biomass. Our models suggest that the fishery is likely to persist for 175 years at the current harvest rate annually or rotationally, though such long-term projections are likely inaccurate. We present methodology to generate scientific advice for the process of determining a maximum sustainable exploitation rate in the form of crash rate analysis. [ABSTRACT FROM AUTHOR]

The Atlantic Zone Monitoring Program (AZMP) was established by Fisheries and Oceans Canada (DFO) in 1998 with the aim of monitoring physical and biological ocean conditions in Atlantic Canada in support of fisheries management. Since 2014, at least two of the carbonate parameters (pH, Total Alkalinity - TA, Dissolved Inorganic Carbon - DIC) have also been systematically measured as part of the AZMP, enabling the calculation of derived parameters (e.g., carbonate saturation states - Ω, partial pressure of CO2 - pCO2, etc.). The present study gives an overview of the spatiotemporal variability of these parameters between 2014 and 2020. Results show that the variability of carbonate parameters reflects changes in both physical (e.g., temperature, salinity) and biological (e.g., plankton photosynthesis and respiration) parameters. For example, most of the region undergoes a seasonal warming and freshening. While the former will tend to increase, the latter will decrease both TA and Ω. Spring and summer plankton blooms decrease DIC near the surface and then remineralize and increase DIC at depth in the fall. The lowest pCO2 values are located in the cold Coastal Labrador Current and the highest in the fresh waters of the Gulf of St. Lawrence and the St. Lawrence Estuary. The latter is also the host of the lowest pH values of the zone. Finally, most of the bottom waters of the Gulf of St. Lawrence are undersaturated with respect to aragonite (Ωarg<1). In addition to providing a baseline of carbonate parameters of the Atlantic Zone as a whole, this comprehensive overview is a necessary and useful contribution for the modeling community and for more in-depth studies. The full data set of measured and derived parameters is available in the Federated Research Data Repository at https://doi.org/10.20383/102.0673. [ABSTRACT FROM AUTHOR]

Arctic fishes are threatened by climatic change and other anthropogenic stressors, yet information on how such changes impact survival remains scarce. Acoustic telemetry has become valuable for studying aspects of fish ecology, including survival, which is invaluable in understanding potential responses to changing conditions. In Cambridge Bay, NU, we have been using acoustic telemetry to study movements and habitat use of the culturally and commercially important Arctic char (Salvelinus alpinus). Here, we combine acoustic telemetry data and Bayesian multistate mark–recapture models to study the survival of Arctic char from 2014 to 2018 in the region in freshwater and marine/estuarine habitats. We found that survival probabilities were high (>0.87) and models considering two environments (freshwater and marine) perform better than those considering three (including estuarine habitats). Furthermore, the survival in fresh water was higher than survival in marine/estuary environments. Overall, the results of this study further our understanding of important demographic parameters (i.e., survival) for Arctic char in the region, which will be useful in refining fishery management plans for the largest commercial fishery for this species in Canada. [ABSTRACT FROM AUTHOR]

Forage fish form a critical trophic link in marine ecosystems, and yet, for many species, there is limited information available. As nations move from single species stock assessments to ecosystem approaches to fisheries management (EAFMs), more information on forage fish will be required. In this study, 50 years of scientific literature were systematically mapped for 11 forage fish species in Canada's Arctic, Atlantic, and Pacific oceans. The objectives were to identify (1) knowledge clusters and gaps and (2) the pressures studied in relation to forage fish outcomes. Of the 2897 articles mapped, the majority studied adults and the distribution, productivity, growth, and life history of commercially fished species. Knowledge gaps were identified for forage fish: (1) that were noncommercially exploited; (2) egg and larval life history stages of most species and juveniles of noncommercial species; (3) diets of most species; (4) migration and performance for all species and survival of noncommercial species; and (5) the effects of some pressures (e.g., large-scale climate pressures). Addressing these knowledge gaps would improve the application of EAFMs. [ABSTRACT FROM AUTHOR]

Environmental impacts on fisheries are pervasive, yet methods to account for them in stock assessments and management decisions vary in rigour and quality. The prevalence and efficacy of methods to account for environmental impacts are not well documented, limiting our ability to adequately respond to future environmental and climate changes for adaptive resource management. In Canada, legislation now requires that environmental conditions are considered in the management of fish stocks, yet the current extent of implementation in assessment processes is poorly understood. We assessed the use of climate, oceanographic and ecological considerations in science advisory processes for 178 stock assessments by Fisheries and Oceans Canada. We evaluated whether these considerations were included in conceptual hypotheses about broad‐scale mechanisms, quantitative or qualitative analyses, and the development of management advice on current or future stock status. Conceptual hypotheses were included in 46% of assessments; quantitative inclusions occurred in 21% of assessments, while qualitative interpretations appeared in 31% of assessments; and 27% of assessments included climate, oceanographic and/or ecological considerations in the advice. Assessments of salmonids, invertebrates and pelagic taxa more frequently made use of environmental data than those for groundfish and elasmobranchs. Comparing our findings with assessments in other jurisdictions highlighted a gap in Canada's ability to respond to environmental changes and a need to develop integrated management approaches, such as regional ecosystem assessments and approaches that combine modelling and empirical analyses, with socio‐economic analysis within interdisciplinary teams. [ABSTRACT FROM AUTHOR]

Sustainable management of exploited populations benefits from integrating demographic and genetic considerations into assessments, as both play a role in determining harvest yields and population persistence. This is especially important in populations subject to size‐selective harvest, because size selective harvesting has the potential to result in significant demographic, life‐history, and genetic changes. We investigated harvest‐induced changes in the effective number of breeders (N̂b) for introduced brook trout populations (Salvelinus fontinalis) in alpine lakes from western Canada. Three populations were subject to 3 years of size‐selective harvesting, while three control populations experienced no harvest. The N̂c decreased consistently across all harvested populations (on average 60.8%) but fluctuated in control populations. There were no consistent changes in N̂b between control or harvest populations, but one harvest population experienced a decrease in N̂b of 63.2%. The N̂b/N̂c ratio increased consistently across harvest lakes; however we found no evidence of genetic compensation (where variance in reproductive success decreases at lower abundance) based on changes in family evenness (FÊ) and the number of full‐sibling families (N̂fam). We found no relationship between FÊ and N̂c or between N̂fam/N̂c and FÊ. We posit that change in N̂b was buffered by constraints on breeding habitat prior to harvest, such that the same number of breeding sites were occupied before and after harvest. These results suggest that effective size in harvested populations may be resilient to considerable changes in Nc in the short‐term, but it is still important to monitor exploited populations to assess the risk of inbreeding and ensure their long‐term survival. [ABSTRACT FROM AUTHOR]

Salmon and herring support both land and ocean predators and are critical to ecosystem resilience. Their linkages across land and sea realms make them highly susceptible to human activities, which can have flow-on effects up the food web. We quantify and compare the potential cumulative effects of human-driven pressures on interdependent species in salmon- and herring-linked ecosystems of western Canada using a risk assessment methodology. Adding indirect risks resulted in 68% greater total risks for land species than for direct risk alone, versus 15% for marine species. Inclusion of climate change pressures resulted in the greatest change in risk for low trophic marine species and habitats (greater than 25% increase). Forestry-related pressures accounted for the highest risk to all species and projected management of these pressures resulted in a total reduction of risk across all ecosystem components that was more than 14% greater than management of fisheries pressures. Ignoring land food web linkages and pressures underestimated cumulative risk by more than 40% for salmon and herring. This simple framework can be used to evaluate potential risk of existing human uses and future change to inform immediate management of linked land-sea ecosystems and help species avoid the 'death by a thousand cuts'. This article is part of the theme issue 'Nurturing resilient marine ecosystems'. [ABSTRACT FROM AUTHOR]

Many of the world's rivers are dammed, altering the physiology, behaviour, ecology and survival of fish. Integrative research has the potential to improve our understanding of these impacts and could enable environmental managers to develop effective solutions for population conservation. Such approaches, however, are not yet prevalent. We use a case study on Pacific salmon (Oncorhynchus spp.) in British Columbia, Canada, to demonstrate how regulated rivers may be used as experimental systems, allowing for applied research that can advance our understanding of the biology of migratory fish as well as our ability to manage them. Through the integration of multiple research approaches (i.e. biotelemetry, behavioural tests, physiological and molecular analyses, and hydraulic monitoring), we characterized the effects of natal water dilution and dam flow releases on upstream navigation, passage success and post-passage survival of returning adult salmon. Our findings confirmed previously established operational guidelines for natal water dilution and informed the adoption of new operational conditions for dam flow releases, providing an example of the successful application of integrative research to the management of a fisheries resource in a regulated river. We encourage researchers to consider using an experimental approach that integrates multiple research disciplines to inform science-based management action. [ABSTRACT FROM AUTHOR]

Georges Bank (GB) has historically been one of the world's most productive fishing grounds. Several formerly abundant groundfish stocks have experienced declines that have resulted in the cessation of directed fisheries. Subsequently, management agencies in both Canada and the United States (U.S.) have implemented various restrictions in an effort to rebuild these stocks; these restrictions include the implementation of closures. Yellowtail Flounder (Limanda ferruginea) and Atlantic Cod (Gadus morhua) are two groundfish stocks that have substantially declined and the rationale for closures on GB has included the need to protect these stocks. In the U.S., these closures are larger and focus more broadly on rebuilding these and other stocks on GB, while in Canada the closures are smaller and directed towards the protection of these two stocks during spawning. This document presents temporally variable species distribution models for these two stocks using a suite of static environmental covariates and presence-absence information from groundfish trawl surveys in Canada and the U.S. These models indicate that there have been both seasonal and long-term shifts in the distribution of both stocks. Significant predictors of the distribution of both stocks throughout the year were the average Sea Surface Temperature (SST; average from 1997-2008) and depth (Dep), while sediment type (Sed) was also a significant predictor for Yellowtail Flounder. The seasonal distribution of the core area of Atlantic Cod is similar in the late winter and spring, while in the fall the distribution shifts to the edge of the bank. For Yellowtail Flounder, the core area is found in a similar location throughout the year. The distribution of Atlantic Cod differed approximately every five years, while the Yellowtail Flounder distribution differed every three years. These shifts in distribution are not random, with the centre of gravity of the core areas for both stocks shifting to the northeast throughout the study period. Much of this shift is due to the loss of core area from southern and western portions of GB. The shifts in the distributions have resulted in an increase in the proportion of both stocks in Canadian waters throughout the year. During Atlantic Cod spawning there has been a substantial decline in the core area inside the two large closures in the U.S. In recent years, Yellowtail Flounder have predominately straddled the Canada-U.S. border; during spawning, the proportion of core area observed in Closed Area II (U.S.) has steadily increased to almost half of the total core area on GB. In Canada, the closures to protect Atlantic Cod and Yellowtail Flounder during spawning both predominately include core area, but due to their limited size these closures make up only a small proportion of the core area on the Canadian portion of GB. Finally, during spawning, the models for both stocks were successful at capturing the spatial dynamics up to three years into the future. The framework methodology applied here provides novel insights into both seasonal and inter-annual variability in the spatial distributions of these stocks and provides a quantitative evaluation of closures relative to these distributions. Incorporation of the information from approaches such as this into the science advice process, can facilitate improved decision-making for fishery management. [ABSTRACT FROM AUTHOR]

An approximate 1:1 sex ratio of American lobsters can be skewed due to environmental factors or fisheries management. Substantial skewness can impact mating behaviour and lower reproduction which could have far-reaching ecological and economic consequences. The aim was to investigate the sex ratio patterns of lobsters in two lobster fishing areas (LFAs) in southwestern Nova Scotia, Canada and identify factors associated with skewed sex ratios. This study analyzed biological data from more than 270,000 lobsters sampled over ten years (2010–2019) by the Fishermen and Scientists Research Society. A mixed effect logistic regression model evaluated the effect of spatial, temporal and environmental factors as well as size on the sex ratio of lobsters. There were significant temporal patterns in sex ratios that differed by LFA. After the effects of sampling month, year and LFA were accounted for, lower bottom temperature and deeper water depth were associated with a higher prevalence of females, especially in larger lobsters. We present the first long term analyses of sex ratio patterns in H. americanus in Atlantic Canada's most commercially important region for this species and provide evidence that these patterns are influenced by environmental factors and fisheries. In view of future climate change scenarios, monitoring the population dynamics of this iconic fishery species is crucial to ensure sustainable fisheries and healthy lobster stocks. [ABSTRACT FROM AUTHOR]

Since 1960, landings of Atlantic herring have been the greatest of any marine species in Canada, surpassing Atlantic cod and accounting for 24% of the total seafood harvested in Atlantic Canada. The Scotian Shelf‐Bay of Fundy herring fisheries (NAFO Division 4VWX) is among Canada's oldest and drives this productivity, accounting for up to 75% of the total herring catch in some years. The stocks' productivity and overall health have declined since 1965. Despite management measures to promote recovery implemented since 2003, biomass remains low and is declining. The factors that drive the productivity of 4VWX herring are primarily unresolved, likely impeding the effectiveness of management actions on this stock. We evaluated potential drivers of herring variability by analyzing 52 time‐series that describe the temporal and spatial evolution of the 4VWX herring population and the physical, ecological, and anthropogenic factors that could affect them using structural equation models. Variation in herring biomass was best accounted for by the exploitation rate's negative effect and the geographic distribution of fishing and recruitment. Thermal phenology and temperature adversely and egg predation positively impacted the early life stage mortality rate and, ultimately, adult biomass. These findings are broadly relevant to fisheries management, but particularly for 4VWX herring, where the current management approach does not consider their early life stage dynamics or assess them within the ecosystem or climate change contexts. [ABSTRACT FROM AUTHOR]

The fishery for Northern Atlantic cod (Gadus morhua) off Newfoundland and Labrador, Eastern Canada, presents the most spectacular case of an exploited stock crashed in a few decades by an industrial bottom trawl fishery under a seemingly sophisticated management regime after half a millennium of sustainable fishing. The fishery, which had generated annual catches of 100000 to 200000 tonnes from the beginning of the 16th century to the 1950s,  peaked in 1968 at 810000 tonnes, followed by a devastating collapse and closure 24 years later. Since then, stock recovery may have been hindered by premature openings, with vessels targeting the remains of the cod population. Previous research paid little attention towards using multicentury time series to inform sustainable catches and recovery plans. Here, we show that a simple stock assessment model can be used to model the cod population trajectory for the entire period from 1508 to 2019 for which catch estimates are available. The model suggests that if fishing effort and mortality had been stabilized in the 1980s,  precautionary annual yields of about 200000 tonnes could have been sustained. Our analysis demonstrates the value of incorporating prior knowledge to counteract shifting baseline effects on reference points and contemporary perceptions of historical stock status. [ABSTRACT FROM AUTHOR]

Effective management of freshwater fish habitat is essential to supporting healthy aquatic ecosystems and sustainable fisheries. In Canada, recent changes to the Fisheries Act enhanced the protection of fish habitat, but application of those provisions relies on sound scientific evidence. We employed collaborative research prioritization methods to identify scientific research questions that, if addressed, would significantly advance the management of freshwater fish habitat in Canada. This list was generated by a diverse group of freshwater fish experts, including substantial contributions from practitioners who administer provisions of the Fisheries Act. The research questions generated in this study identify priority topics for future research, while highlighting issues that could be addressed with different funding models. As a result, this study should support evidence-based management of Canada's aquatic resources by identifying scientific knowledge gaps faced by practitioners, and suggesting mechanisms to address them. Given the important contribution of Canadian freshwater systems to global ecosystem values, and the similar scientific challenges facing fish habitat managers in other jurisdictions, this study is likely to have broad applicability. [ABSTRACT FROM AUTHOR]

Salmonids have emerged as important study systems for investigating molecular processes underlying parallel evolution given their tremendous life history variation. Kokanee, the resident form of anadromous sockeye salmon (Oncorhynchus nerka), have evolved multiple times across the species' pan-Pacific distribution, exhibiting multiple reproductive ecotypes including those that spawn in streams, on lake-shores, and at lake depths >50 m. The latter has only been detected in 5 locations in Japan and British Columbia, Canada. Here, we investigated the multiple origins hypothesis for deep-spawning kokanee, using 9721 single nucleotide polymorphisms distributed across the genome analyzed for the vast majority of known populations in Japan (Saiko Lake) and Canada (Anderson, Seton, East Barrière Lakes) relative to stream-spawning populations in both regions. We detected 397 outlier loci, none of which were robustly identified in paired-ecotype comparisons in Japan and Canada independently. Bayesian clustering and principal components analyses based on neutral loci revealed 6 distinct clusters, largely associated with geography or translocation history, rather than ecotype. Moreover, a high level of divergence between Canadian and Japanese populations, and between deep- and stream-spawning populations regionally, suggests the deep-spawning ecotype independently evolved on the 2 continents. On a finer level, Japanese kokanee populations exhibited low estimates of heterozygosity, significant levels of inbreeding, and reduced effective population sizes relative to Canadian populations, likely associated with transplantation history. Along with preliminary evidence for hybridization between deep- and stream-spawning ecotypes in Saiko Lake, these findings should be considered within the context of on-going kokanee fisheries management in Japan. [ABSTRACT FROM AUTHOR]

Wild Pacific salmon, including Chinook salmon Oncorhynchus tshawytscha, have been supplemented with hatchery propagation for over 50 years in support of increased ocean harvest, mitigation for hydroelectric development, and conservation of threatened populations. In Canada, the Wild Salmon Policy for Pacific salmon was established with the goal of maintaining and restoring healthy and diverse Pacific salmon populations, making conservation of wild salmon and their habitats the highest priority for resource management decision‐making. For policy implementation, a new approach to the assessment and management of Chinook salmon and the associated hatchery production and fisheries management are needed. Implementation of genetic stock identification (GSI) and parentage‐based tagging (PBT) for marine fisheries assessment may overcome problems associated with coded‐wire tag‐based (CWT) assessment and management of Chinook salmon fisheries, providing at a minimum information equivalent to that derived from the CWT program. GSI and PBT were used to identify Chinook salmon sampled in 2018 and 2019 marine fisheries (18,819 individuals genotyped) in British Columbia to specific conservation units (CU), populations, and broodyears. Individuals were genotyped at 391 single nucleotide polymorphisms via direct sequencing of amplicons. Very high accuracy of assignment to population and age (>99.5%) via PBT was observed for 1994 Chinook salmon of ages 2–4 years, with a 105,722–individual, 380–population baseline available for assignment. Application of a GSI‐PBT system of identification to individuals in 2019 fisheries provided high‐resolution estimates of stock composition, catch, and exploitation rate by CU or population, with fishery exploitation rates directly comparable to those provided by CWTs for 13 populations. GSI and PBT provide an alternate, cheaper, and more effective method in the assessment and management of Canadian‐origin Chinook salmon relative to CWTs, and an opportunity for a genetics‐based system to replace the current CWT system for salmon assessment. [ABSTRACT FROM AUTHOR]

The rate of climate change (CC) has accelerated to the point where it now affects the mid- to long-term sustainability of fishing strategies. Therefore, it is important to consider practical and effective ways to incorporate CC into fisheries advice so that the advice can be considered conditioned to CC. We developed a model to characterise the empirical relationship between a variable affected by climate and fish production. We then used model projections as a foundation for a risk analysis of CC effects on harvesting of Greenland halibut Reinhardtius hippoglossoides in the Gulf of St Lawrence, Canada. The risk-based approach quantified a) the relative change in risk of a status quo fishing strategy under various CC scenarios, and b) the change in fishery exploitation rates required to achieve a management objective over a specified time period at a level of risk considered acceptable (risk equivalent fishery exploitation advice). This empirical approach can be used to develop risk-based advice for any other external variable that affects stock production in addition to climate-related variables and it can be applied in most situations where there is an index of stock biomass and fisheries catch. Shifting the focus from process-based understanding of the responses of fish stocks to CC to quantification of how CC-contributed uncertainty can alter the risks associated with different fishing strategies and/or management options, can ensure timely delivery of robust scientific advice for fisheries under non-stationary environmental conditions. [ABSTRACT FROM AUTHOR]

The document provides a list of upcoming fisheries-related conferences and meetings taking place between January and March 2024. The events are held in various locations across the United States and Canada, covering topics such as aquaculture, fish and wildlife conservation, and ecosystem management. The conferences offer opportunities for professionals and researchers in the field to network, share knowledge, and discuss the latest developments in fisheries science and management. [Extracted from the article]

This article is the Introduction to the Special Feature entitled: Canada and Transboundary Fisheries Management in Changing Oceans: Taking Stock, Future Scenarios. We summarize the research context of the four papers in the Special Feature. [ABSTRACT FROM AUTHOR]

We apply the concept of threat points in game theory to explore the stability of current joint management arrangements for shared transboundary fish stocks between Canada and the United States. We use three examples to explore the effects of projected impacts of climate change on the productivity and distribution of these stocks between the exclusive economic zones of the two countries. The three stocks that we study are: Atlantic cod (Gadus morhua) and yellowtail flounder (Limanda ferruginea) within the Gulf of Maine, and Pacific halibut (Hippoglossus stenolepis) in the Pacific Coast. We define a threat point as the payoffs that the fisheries in Canada and the United States take home given the current management agreement between the two countries. This is an application of John Nash's threat point, defined as the minimum payoffs that each player in a game theoretic model must receive for the solution to a cooperative game to be stable, which is usually the outcome of a noncooperative game. First, we compute the threat points, that is, the current profits that Canada and the United States derive from the three shared stocks, respectively. Next, we build an ensemble of climate-marine ecosystem and economic models and use them to determine how climate change is likely to change current profits received by each country relative to the shifts in their threat points. We find that in some cases the profits obtained by fisheries in Canada and the United States would change under climate change both in absolute and relative terms resulting in relative changes in threat points. These relative changes in threat points serve as the basis for our discussion of the stability of current transboundary management agreements between Canada and the United States for these important shared stocks in the face of climate change. [ABSTRACT FROM AUTHOR]

The size selectivity of four codends were compared in the Gulf of St. Lawrence, Canada, redfish fishery (Sebastes mentella), including the regulated diamond mesh codend with a mesh opening of 90 mm (T0) and three experimental codends of different mesh openings (90, 100, 110 mm) in which the netting is turned 90° to the direction of tow (T90). Results for the regulated codend showed that there was little size selection, catching greater than 97% of redfish over all of the length classes observed. Considering the fished population, the smallest T90 codend would catch 30% fewer redfish under the minimum landing size (MLS) of 22 cm compared with the T0 codend, but would also lose 16% of catch above 22 cm. The T90 codend with 100 mm mesh opening had the same size selectivity as the smallest T90 codend. The 110 mm T90 codend would catch 50% less redfish below MLS but lose 40% of redfish above MLS. Overall, results show that T90 codends improve size selectivity in which large proportions of undersized fish are successfully released. [ABSTRACT FROM AUTHOR]

Direct DNA sequencing is powering a revolution in the application of genetics to resource management, with parentage-based tagging (PBT) increasingly applied to salmon fisheries and hatchery brood stock management and assessment. Genetic stock identification (GSI) and PBT were applied to assessment of 2018 coho salmon (Oncorhynchus kisutch) ocean fisheries and hatchery brood stocks in British Columbia (BC), Canada, with 6391 individuals successfully genotyped in fishery samples and 7805 individuals genotyped in 40 hatchery brood stocks. Population-specific contributions to mixed-stock fisheries and exploitation rates were estimated with coded-wire tags (CWTs) and GSI–PBT technologies for six populations. PBT assignments, verified by CWTs, were 100% accurate for 308 individuals with respect to population of origin and age. There was generally reasonably close agreement of estimated population-specific exploitation rates between CWT and genetic methods. We conclude that a genetic approach can improve upon the results available from the current CWT program for assessment and management of coho salmon fisheries and hatchery brood stocks in BC and provide information critical to aid in implementation of Canada's Policy for Conservation of Wild Pacific Salmon. [ABSTRACT FROM AUTHOR]

This study incorporated two pathways of environmental forcing (i.e. "larval mortality forcing" and "somatic growth forcing") into an end-to-end ecosystem model (Object-oriented Simulator of Marine ecOSystEms, OSMOSE) developed for the Pacific North Coast Integrated Management Area (PNCIMA) off western Canada, in order to evaluate alternative fisheries management strategies under environmental changes. With a suite of ecosystem-level indicators, the present study first compared the ecosystem effects of different pathways of environmental forcing scenarios; and then evaluated the alternative fisheries management strategies which encompassed a series of fishing mortality rates relative to F MSY (the fishing mortality rate that produces maximum sustainable yield) and a set of precautionary harvest control rules (HCRs). The main objectives of this study were to (i) explore the ecosystem effects of different environmental forcing scenarios; (ii) identify the impacts of different fishing mortality rates on marine ecosystem structure and function; and (iii) evaluate the ecosystem-level performance of various levels of precautionary HCRs. Results indicated that different pathways of environmental forcing had different ecosystem effects and incorporating appropriate HCRs in the fisheries management process could help maintain ecosystem health and sustainable fisheries. This study provides important information on future fisheries management options within similar marine ecosystems that are facing global changes. [ABSTRACT FROM AUTHOR]

In 1995, the so-called "turbot war" between Spain and Canada was pivotal for Iberian fisheries. The main objective of this research is to revisit the turbot war to reflect on the issue of governing fisheries on the high seas, the cause behind the war, and how it was resolved. This paper provides guidelines for future research on the management of high seas fisheries. [ABSTRACT FROM AUTHOR]

Indicator-based frameworks for assessing the sustainability of commercial fisheries have become well-established in the consumer sector. Within fisheries management, there are only a few jurisdictions, notably Australia, where sustainability frameworks are regularly used across the full spectrum of management functions, including planning, decision making, and evaluation. In Canada, a "sustainable fisheries framework" has been proposed but implementation has been limited to date. The Canadian Fisheries Research Network (CFRN), a six-year collaboration between Fisheries and Oceans Canada (DFO), the commercial fishing industry, and academic institutions, included as one of its major outputs the development of a comprehensive framework-based approach to evaluate the sustainability of commercial fisheries in Canada. Although most fisheries sustainability frameworks focus on the ecological domain, the CFRN explicitly recognized the social, economic, and institutional domains as having equal importance in a holistic treatment of sustainability. Following an iterative research and development process, a subgroup within the CFRN produced a novel sustainability indicator framework that combines a hierarchical subject matter structure consisting of domains, dimensions, and elements with a formula approach to developing indicators that utilizes a system of variables, or attributes. These two aspects of the sustainability indicator framework are linked in a way that helps to enforce comprehensive and routine methods for identifying objectives and relating those to specific indicators. The careful balancing of scope and depth makes for a powerful tool that can be used across a range of fisheries management contexts within Canada and in other jurisdictions that have a similar governance structure and high degree of institutional capacity. We present a detailed account of how the sustainability indicator framework was developed, the logic of its construction, and its potential application in fisheries management. [ABSTRACT FROM AUTHOR]

• Developed a guidance framework for the selection and evaluation of indicators. • Selected a suite of parsimonious, complementary indicators using clear criteria. • Applied the framework to the Scotian Shelf Bioregion, at multiple spatial scales. • Patterns of redundancy among indicators generally consistent at all spatial scales. • The Scotian Shelf has endured huge negative change with limited signs of recovery. Ecosystem indicators are key to understanding, assessing, and managing ecosystems and to implementing an Ecosystem Approach to Management. We present a guidance framework for the selection and evaluation of indicators for assessment of ecosystem status, trends monitoring and reporting and apply it to the Scotian Shelf Bioregion, Nova Scotia, Canada. In particular, we focus on the selection of a parsimonious suite of complementary indicators using clear criteria and hierarchical cluster analysis to reduce redundancy in the indicator suite. In applying the framework to the Scotian Shelf Bioregion we separate the region into a range of spatial scales for indicator estimation to determine the impact of spatial aggregation on indicator redundancy. Overall results suggest patterns of redundancy among indicators were generally consistent at all spatial scales. Differences in indicator trends for eastern and western Scotian Shelf were observed, reflecting their different environmental properties and fishing histories. In a few cases, spatial differences in indicators trends were large enough to remove these indicators from a cluster representing all spatial scales. We recommend that the Redundancy Analysis should be repeated every 5–10 years to ensure that the clusters are still strong and that the indicator selected to represent the cluster is still optimal. Overall, the assessment of the Scotian Shelf Bioregion highlighted large coherent trends across indicators and attributes at all spatial scales indicating that this system has undergone massive, negative change since 1970. Despite reductions in fishing pressure in many fisheries through resource management actions, most attributes have not improved in recent years. This Framework represents a general approach that can be extended to additional system goals, attributes and indicators and is widely applicable across data rich and data poor systems. [ABSTRACT FROM AUTHOR]

Biotelemetry data have been successfully incorporated into aspects of fishery and fish habitat management; however, the processes of knowledge mobilization are rarely published in peer-reviewed literature but are valuable and of interest to conservation scientists. Here, we explore case examples from the Ocean Tracking Network (OTN), including Pacific salmon (Oncorhynchus spp.) in British Columbia, Canada; Greenland halibut (Reinhardtius hippoglossoides) in Cumberland Sound, Canada; and lemon sharks (Negaprion brevirostris) in Florida, USA, to document key processes for science integration. Typical recommendations documented in the literature (e.g., co-production of knowledge, transdisciplinary methodologies, applied research questions) were recorded to have had successful fisheries management integration, although we documented some exceptions. In each case, it was early, active, and ongoing communication outside of traditional science communication and the visual evidence of fish movement that were critical in engaging all parties with a vested interest. Networks offer forums for knowledge sharing on lessons learned and development of skills to engage in active communication. Greater investments and attention to develop these skills are needed to foster positive and active relationships that can impart real change in management and conservation. [ABSTRACT FROM AUTHOR]

Fisheries are complex social–ecological systems with multiple potential linkages between fish and anglers. Understanding these linkages helps to support effective fisheries management. We examine the social–ecological dynamics of a recreational fishery by assessing relationships between fish, anglers, and a management intervention. We focus on catch-and-release steelhead trout (Oncorhynchus mykiss) fisheries on six rivers within the Skeena River watershed, British Columbia, Canada, the location of a recent management intervention. First, based on analyses of annual steelhead trout abundance and annual angler effort information, we found that years with a higher abundance of returning steelhead trout were associated with years of higher catch rates and angler effort. Second, based on analyses of nonresident angler effort, we discovered that a new management intervention provided periods of lower angler effort, but effort was apparently redistributed to other rivers and time periods. Third, responses from angler interviews post-management intervention revealed that anglers were more satisfied if they caught more fish and experienced less crowding; at higher crowding levels, higher catch rates were required to increase angler satisfaction. In conclusion, we found that this recreational fishery is influenced by both human dimensions and natural ecological dynamics such as fish population fluctuations. [ABSTRACT FROM AUTHOR]

Understanding the genetic and evolutionary impacts of stocking on wild fish populations has long been of interest as negative consequences such as reduced fitness and loss of genetic diversity are commonly reported outcomes. In an attempt to sustain a fishery, managers implemented nearly five decades of extensive stocking of over a million Muskellunge (Esox masquinongy), a native species in the Lower St. Lawrence River (Québec, Canada). We investigated the effect of this stocking on population genetic structure and allelic diversity in the St. Lawrence River in addition to tributaries and several stocked inland lakes. Using genotype by sequencing, we genotyped 643 individuals representing 22 locations and combined this information with forward simulations to investigate the genetic consequences of long‐term stocking. Individuals native to the St. Lawrence watershed were genetically differentiated from stocking sources and tributaries, and inland lakes were naturally differentiated from the main river. Empirical data and simulations within the St. Lawrence River revealed weak stocking effects on admixture patterns. Our data suggest that the genetic structure associated with stocked fish was diluted into its relatively large effective population size. This interpretation is also consistent with a hypothesis that selection against introgression was in operation and relatively efficient within the large St. Lawrence River system. In contrast, smaller populations from adjacent tributaries and lakes displayed greater stocking‐related admixture that resulted in comparatively higher heterozygosity than the St. Lawrence. Finally, individuals from inland lakes that were established by stocking maintained a close affinity with their source populations. This study illustrated a benefit of combining extensive genomic data with forward simulations for improved inference regarding population‐level genetic effects of long‐term stocking, and its relevance for fishery management decision making. [ABSTRACT FROM AUTHOR]

The Canadian Fisheries Research Network (CFRN) was a collaboration among fish harvesters, academic researchers, and government scientists that undertook research between 2010 and 2016 on questions about fisheries that were identified by fish harvesters and pertinent to management objectives. This paper provides a synthesis of the scope and results of the CFRN. It explores the link between the increasing challenges to fisheries sustainability and the need for increased research capacity and for a collaborative approach. It documents the creation of the collaboration, the research it accomplished, and its benefits and explores the need for ongoing collaboration. The papers in this special issue on the CFRN demonstrate the benefits of collaborative fisheries research that are of relevance internationally and support the need for a permanent collaborative platform to conduct research to support fisheries management capacity and decision-making in Canada. [ABSTRACT FROM AUTHOR]

An interdisciplinary team of academics and representatives of fishing fleets and government collaborated to study the emerging requirements for sustainability in Canada's fisheries. Fisheries assessment and management has focused on biological productivity with insufficient consideration of social (including cultural), economic, and institutional (governance) aspects. Further, there has been little discussion or formal evaluation of the effectiveness of fisheries management. The team of over 50 people (i) identified a comprehensive set of management objectives for a sustainable fishery system based on Canadian policy statements, (ii) combined objectives into an operational framework with relevant performance indicators for use in management planning, and (iii) undertook case studies that investigated some social, economic, and governance aspects in greater detail. The resulting framework extends the suite of widely accepted ecological aspects (productivity and trophic structure, biodiversity, and habitat–ecosystem integrity) to include comparable economic (viability and prosperity, sustainable livelihoods, distribution of access and benefits, regional–community benefits), social (health and well-being, sustainable communities, ethical fisheries), and institutional (legal obligations, good governance structure, effective decision-making) aspects of sustainability. This work provides a practical framework for implementation of a comprehensive approach to sustainability in Canadian fisheries. The project also demonstrates the value of co-construction of collaborative research and co-production of knowledge that combines and builds on the strengths of academics, industry, and government. [ABSTRACT FROM AUTHOR]

Many monitoring programs are employed across the numerous and diverse fisheries in Canada to estimate parameters that are used directly in fishery management or are used to produce scientific advice for the sustainable management of fisheries. These parameters include catch amounts or catch rates for targeted and incidentally captured species, catch composition (e.g., size composition, percentage of soft-shelled crustaceans) and fishing effort. Fisheries and Oceans Canada (DFO) is currently finalizing a national fishery monitoring policy to ensure that it has dependable, timely and accessible information on fisheries to manage them sustainably and to ensure a unified approach for setting the type and degree of monitoring employed across fisheries nationwide. This report presents an important component for the implementation of the new policy: a unified framework to evaluate the quality (how close a parameter estimate is to the true value) and dependability (ability of an estimation process to achieve its intended objectives) of DFO's fishery monitoring programs. Quality and dependability are affected by statistical characteristics of the monitoring program design and by operational characteristics which result in deliberate or unintentional differences between the implementation of the program and the program design, or which contribute data errors (e.g., measurement, data handling and modelling errors). The proposed assessment framework accounts for statistical and operational characteristics of a program and can be implemented using quantitative data and expert opinion. It is structured and founded on statistical concepts which are used heuristically to ensure consistent application and rigor. Furthermore, the framework is applicable to parameter estimations that are used directly (e.g., catch amounts for stock assessment purposes) or that are used to gauge compliance with respect to some limit (e.g., fulfillment of a quota or achievement of a bycatch limit). The goal for this report is to provide the details of and relevant justifications for the proposed assessment framework. Technical details are provided only where they are required; however, this report is not meant to be a user's guide and a separate document will therefore be required for the implementation of the proposed assessment framework. [ABSTRACT FROM AUTHOR]

The abundance of top predators in the southern Gulf of St. Lawrence, Canada, has fluctuated dramatically in recent decades. The associated increase in predation and its effect on the lack of recovery of many fish stocks in the system generates the need for a better understanding of predator-prey relationships and the implementation of an ecosystem approach to fisheries management. This study used stomach content analysis to further describe the diet of Atlantic bluefin tuna in the southern Gulf of St. Lawrence. Teleost fish largely dominated the stomach contents in all years. Previous studies established that Atlantic herring was the main component of the diet by weight, whereas herring was almost absent from the diet in this study. A shift in the diet of Atlantic bluefin tuna has been observed, as it now feeds almost exclusively on Atlantic mackerel. The estimated daily meal varied between years, ranging from 1026 g per day in 2019 to 2360 g per day in 2018. Daily meals and daily rations were calculated and showed substantial year-to-year variation. • The diet of Atlantic bluefin tuna was studied in the southern Gulf of St Lawrence between 2010 and 2021. • Stomach contents were identified visually and by DNA barcoding. • Teleosts (Atlantic herring and Atlantic mackerel) largely dominated the diet in all years. • A shift in Atlantic bluefin tuna diet was observed in recent years. • The diet was almost exclusively composed of Atlantic mackerel in recent years. [ABSTRACT FROM AUTHOR]

Canadian fisheries and aquaculture industry provide employment to a major part of the population in several coastal provinces of Canada. This review has summarized different species employed in commercial fishing and aquaculture industry, status of these industries' production observed in past few decades, and other aspects of Canadian fisheries. Similar to other food industries, these industries face a lot of vicissitudes, especially in production and commercial landings of fishes, which also significantly affects the local and global economy. However, valorisation of the underutilized and invasive species along with fishery byproducts and wastes generated from these industries can enhance the industry's value chain, which can improve the profitability of the products while simultaneously warding off low-cost competitors Valorisation and production of various high value pharmaceuticals/nutraceuticals (marine oils, omega-3 fatty acids, proteins, amino acids, enzymes, chitin, chitosan and astaxanthin etc.) from these resources can maximize the economic viability of the industry, while addressing issues of waste management and environmental sustainability. Currently, one of the most popular nutraceuticals, poly-unsaturated fatty acids mainly omega-3 fatty acids are obtained from marine fishes with high fat content and oil seeds. However, with increasing awareness about the beneficial effects of these fatty acids, growing demand and dosage requirements according to the ongoing in-vivo and in-vitro studies, nutraceutical supplements are being decidedly encouraged by nutritionists. High demand has motivated researchers for pursuing new sources of these fatty acids, improve existing extraction methods and develop more efficient methods for mass production and commercialisation. This review has also summarized traditional and new sources (corresponding industrial by-products) of omega-3 fatty acids, and extraction techniques with the potential of producing high quality omega-3 fatty acids, clinical effects of omega-3 fatty acids, and future aspects of research in this area. [ABSTRACT FROM AUTHOR]

Atlantic halibut (Hippoglossus hippoglossus) is an increasingly valued commercial fish and its recent population growth has attracted the attention of fisheries scientists and managers both within and outside Canada. With renewed transnational interests in this species, fishery managers have relied on existing, but limited, ecological information for multilateral discussions on shared allocations of catch. To address this dearth of information, we modeled species distribution using maximum entropy, where by survey catch data were related to environmental data to quantify habitat suitability. We then calculated the amount of suitable habitat for juvenile Atlantic halibut per Northwest Atlantic Fisheries Organization (NAFO) divisions, within and outside Canada's Exclusive Economic Zone. Among NAFO divisions, we found a strong relationship between the availability of suitable habitat for juvenile Atlantic halibut, and both current and historical fisheries landings. Results are consistent with the nursery-size hypothesis which states that the amount of available juvenile habitat is related to the level of adult production. The majority of occupied suitable habitat is found on the southwestern half of Canada's Scotian Shelf, whereas the U.S. and international waters off Newfoundland have ample suitable habitat to support larger populations. Quantifying habitat suitability and linking this suitability to stock abundance and distribution is an important step toward an ecosystem approach for the management of Atlantic halibut. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of fisheries and forestry governance in the Canadian provinces surrounding the Gulf of Saint Lawrence. It serves two purposes. The first is to produce a portrait of the trends challenging the hypothesis of a shrinking natural resources economy in these territories, in order to underline both the complexity of the struggles taking place around their ressourcist vocation, and the political tensions shaping the recasting of the extractivist model of development. The second, more theoretical and methodological contribution, is a reflection on the conceptual framework developed here: it aims to show the scope and utility of a combination of (1) a sectoral governance analysis and (2) a territorialized analysis of collective action around resource governance. This combination offers an interesting insight into the struggles and political tensions surrounding the tentative restructuring of the Canadian extractivist model. To do so, we examine the two sectoral trajectories showing signs of indecisiveness and adopt a territorial approach which reveals the numerous and various pressures on territories. A disconnection is thus observed between the sectoral and territorial levels: major frames of reference are gradually opening to encompass social and environmental issues, but this relative opening is not being directly and efficiently translated into practices, despite various innovations and indications of openness in governance processes. This fault line leads us to question the power relationships and power imbalances at work within these governance mechanisms and see how these scenes of struggle provide insights into the ambivalence of the current development trajectory. [ABSTRACT FROM AUTHOR]

Ecosystem models are valuable tools for informing fisheries management due to their ability to simulate the spatial dynamics of modelled species, their trophic interactions, and their responses to fishing in an ecosystem context. In this study, we developed an OSMOSE (Object-oriented Simulator of Marine Ecosystems Exploitation) model for the Pacific North Coast Integrated Management Area (PNCIMA) ecosystem off western Canada, which simulated the entire life cycle of six key species and for the first time integrated spatial population structure and "background" taxa. Background taxa are of secondary importance for the study at hand but have the potential to be important prey or predators of the key species. The primary aim of the study was to explore how the population dynamics of the key species differed over time and different management areas, with results focusing on Pacific Herring (Clupea pallasii) and Pacific Cod (Gadus macrocephalus) that have been assessed on a single-species basis in the last 5 years. Results found that the population dynamics of a specific species varied in different management areas due to differences in species interactions particularly in the form of predation mortality, which supports the current area-specific assessment and management framework. The study also indicated that increasing predation mortality may have caused the decline of the Pacific Cod populations. By contrast, increasing starvation mortality was found to be a limiting factor for the Pacific Herring populations. The discoveries from these OSMOSE simulations provide important information for fisheries management within the PNCIMA ecosystem. [ABSTRACT FROM AUTHOR]