Catch yield and selectivity of a modified scallop dredge to reduce seabed impact.

Global scallop fisheries are economically important but are associated with environmental impacts to seabed communities resulting from the direct physical contact of the fishing gear with the seabed. Gear modifications attempting to reduce this contact must be economically feasible such that the catch numbers for the target species is maintained or increased. This study investigated the outcome of reducing seabed contact on retained catch of scallops and bycatch by the addition of skids to the bottom of the collecting bag of scallop dredges. We used a paired control experimental design to investigate the impact of the gear modification in different habitat types. The modified skid dredge generally caught more marketable scallops per unit area fished compared with the standard dredge (+5%). However, the skid dredge also retained more bycatch (+11%) and more undersize scallops (+16%). The performance of the two dredges was habitat specific which indicates the importance of adjusting management measures in relation to habitat type. To realize the potential environmental benefits associated with the improvement in catchability of this gear modification, further gear modification is required to reduce the catch of undersize scallops and bycatch. Furthermore we advocate that technical gear innovations in scallop dredging need to be part of a comprehensive and effective fisheries management system.

Impacts of bycatch from beach seining: a case study of a shrimp fishery in Brazil.

It is commonly assumed that beach seining (BS) is more sustainable than bottom trawling because it involves non-motorized operations and limited fishing power. However, no scientific evidence supports this assumption. To address this gap, we evaluated the impact of beach seining, taking a small-scale shrimp fishery in northeast Brazil. Data collected monthly from December 2016 to November 2017 and in literature, were assessed (BS 31,001 individuals, 119 species, 37 families, and 19 orders; BT 6,031 individuals, 58 species, 20 families, and 14 orders). Beach seining demonstrated a lower proportion of bycatch (BS 1:2.3; BT 1:3.2), higher total shrimp catch (BS 87.2 t; BT 65 t), and greater species diversity than bottom trawling catches (BS 119; BT 58). Other aspects were closer associated with bottom trawling, such as the composition of dominant families (Sciaenidae and Pristigasteridae), the proportion of rare species (BS 30%; BT 24%) juveniles (BS 11g; BT 13g), the risk of species extinction, and the composition of ecological guilds. Despite their social significance, both fishing gears showed similar ecological indicators and adverse effects. The findings establish that the ecological concerns related to the impact of bottom trawling are also applicable to beach seine.

Fishing profile and commercial landings of shark and batoids in a global elasmobranchs conservation hotspot.

This paper describes the fishing profile and the temporal variation in the commercial landings of elasmobranchs in a global hotspot for their conservation and investigates the variables that influenced the landings. Census data on commercial catches were obtained between April 2008 and October 2010 from nine landing sites in Bragança (Pará, northern Brazil). Five vessel types, four fishing gears, and eight fishing techniques engaged with elasmobranch capture were identified. A total of 2,357 landings were recorded, with a total production of 354 t. The highest yields were recorded in 2009, with sharks being harvested mostly by small and medium-sized vessels, and batoids, by small vessels and canoes. Drifting nets and longlines played a prominent role in elasmobranch fisheries. The results show that the landings were influenced by days at sea, which is common in tropical fisheries. The elasmobranch data series is discontinuous as statistics are absent for most fishing sites albeit imperative for proper management, as well as relevant for decision-makers focusing on their conservation.

Calibration of commercial fisheries echo sounders using seabed backscatter for the estimation of fishery resources.

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.

Real-world waste dispersion modelling for benthic integrated multi-trophic aquaculture.

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.

Climate change: A pointer to increased small-scale fisher drowning deaths.

Drowning is an overlooked public health concern and drowning risk is dependent on environmental risk factors. The preponderance of drowning deaths occurs in low- and middle-income countries. Small-scale fishers face high occupational risk of drowning. Climate change increases the frequency and intensity of storms, thereby exacerbating fishers' risks and creating a need to examine the contribution of storms to fisher drowning deaths for the development of mitigation strategies. We examined this relationship between weather and fisher drowning deaths in Lake Victoria, which is Africa's largest lake, a site of high fishing pressure, and where climate change is predicted to increase thunderstorms. We conducted a verbal autopsy with people knowledgeable about recent fatal fisher drowning incidents to collect information about the deceased fishers and circumstances surrounding the incidents across 43 landing sites in the Kenyan shore of Lake Victoria. Semi-structured interviews with stakeholders also elucidated community perspectives on drowning risks. Fatal drownings were often attributed to bad weather (41.8%). Other risk factors, such as non-use of life jacket and navigation equipment, co-occurred with bad weather at high rates (69.5% and 67.8%, respectively) to jointly contribute to fatal drowning incidents. Such co-occurrence of risk factors indicates that actions across multiple risk factors can help mitigate the issue. Stakeholder analysis revealed a range of opportunities for improved communication of risks and action to mitigate risks across boat operators and manufacturers, as well as multiple levels of management. Across global small-scale fisheries, limited use of safety equipment and intensive fishing pressure may coincide with increases in extreme weather events, necessitating action to address current and mitigate future drowning risks to small-scale fishers.

Geolocated fish spawning habitats.

Fish spawning locations are a crucial input into fisheries management and conservation plans, and many stocks are especially sensitive to the environmental conditions within these localized zones. Globally collated data on spawning locations across many species has been unavailable, hindering global stock assessments and analyses of sustainable development and global environmental change. To address this, we created a geocoded fish spawning dataset using qualitative spawning information from FishBase and Science and Conservation of Fish Aggregations (SCRFA). We cleaned and geocoded the spawning locations of 1,045 marine fish species into 2,931 regions. Each spawning region is defined by one or more polygons, and most spawning regions are associated with spawning months. The resulting dataset covers oceans globally. This dataset will be useful to scientists studying marine fish population dynamics and their interactions with the physical environment on regional to large scales.

Caribbean red snapper fishing performance indicators in Brazilian amazon shelf: Is it the beginning of the end of a fishing system?

Red snapper fishing (Lutjanus purpureus) is an important fishing activity for the Brazilian economy due to its export. The scarcity of up-to-date information on this system's ecology, economy, and social characteristics contributes to inefficient management. We analyze whether the commercial snapper fishery on the Amazon continental shelf is socioecologically sustainable. For this, an assessment tool was used that can be applied to fishing systems with little data, the Fisheries Performance Indicators (FPI). The results showed that the critical points of this activity are mainly related to the Ecological indicator (2.3) and the Economic indicator (2.8). The best indicator was the Community (3.8). The problems that put at risk the permanence of the activity and its maintenance are: (i) fishing for juveniles; (ii) illegal vessels; (iii) lack of collaboration of the fishing sector with science, and (iv) unreliability of data supplied. All the points mentioned make the snapper fishery on the north coast of Brazil socio-ecologically unsustainable in the long term.

3D ocean assessments reveal that fisheries reach deep but marine protection remains shallow.

The wave of new global conservation targets, the conclusion of the High Seas Treaty negotiations, and the expansion of extractive use into the deep sea call for a paradigm shift in ocean conservation. The current reductionist 2D representation of the ocean to set targets and measure impacts will fail at achieving effective biodiversity conservation. Here, we develop a framework that overlays depth realms onto marine ecoregions to conduct the first three-dimensional spatial analysis of global marine conservation achievements and fisheries footprint. Our novel approach reveals conservation gaps of mesophotic, rariphotic, and abyssal depths and an underrepresentation of high protection levels across all depths. In contrast, the 3D footprint of fisheries covers all depths, with benthic fishing occurring down to the lower bathyal and mesopelagic fishing peaking in areas overlying abyssal depths. Additionally, conservation efforts are biased towards areas where the lowest fishing pressures occur, compromising the effectiveness of the marine conservation network. These spatial mismatches emphasize the need to shift towards 3D thinking to achieve ocean sustainability.

Unlocking the potential of blockchain technology in enhancing the fisheries supply chain: an exploration of critical adoption barriers in China.

The application of blockchain technology holds significant potential for improving efficiency, resilience, and transparency within the Fisheries Supply Chain (FSC). This study addresses the critical barriers hindering the adoption of blockchain technology (BT) in the Chinese FSC, recognizing the unique challenges posed by its intricacies. Through a comprehensive literature review, fourteen Critical Barrier Factors (CBFs) were identified, and a grey Delphi method was employed to distill this set. Five pivotal CBFs emerged, including "Regulatory Compliance," "Cost of Implementation," and "Complex Supply Chain Network". A subsequent grey Decision-Making Trial and Evaluation Laboratory (DEMATEL) analysis revealed the causal relationships among these factors, categorizing them into effect and cause groups. "Regulatory Compliance," "Cost of Implementation," and "Complex Supply Chain Network" were identified as primary influencing factors demanding attention for effective BT integration in the FSC. The findings serve as a valuable resource for FSC stakeholders, assisting in prioritizing efforts to address these barriers. The discerned causal relationships provide guidance for managers in optimizing resource allocation. Ultimately, this research advocates for the adoption of blockchain technology in the fisheries supply chain to enhance overall performance and operational efficiency.

Projected habitat preferences of commercial fish under different scenarios of climate change.

The challenges of commercial species with the threats of climate change make it necessary to predict the changes in the distributional shifts and habitat preferences of the species under possible future scenarios. We aim to demonstrate how future climatic changes will affect the habitat suitability of three species of commercial fish using the predictive technique MaxEnt. The dataset used to extract geographical records included OBIS (54%), GBIF (1%), and literature (45%). The output of the model indicated accurate projections of MaxEnt (AUC above 0.9). Temperature was the main descriptor responsible for the main effects on the distribution of commercial fish. With increasing RCP from 2.5 to 8.5, the species would prefer saltier, higher temperatures and deeper waters in the future. We observed different percentages of suitable habitats between species during RCPs showing distinct sensitivity of each fish in facing climate changes. Negative effects from climate change on the distribution patterns of commercial fish were predicted to lead to varying degrees of reduction and changes of suitable habitats and movement of species towards higher latitudes. The finding emphasizes to implement adaptive management measures to preserve the stocks of these commercial fish considering that the intensification of the effects of climate change on subtropical areas and overexploited species is predicted.

Environmental DNA as a tool to reconstruct catch composition for longline fisheries vessels.

Global wild-capture fisheries are a large and diverse sector requiring various tools for fisheries-dependant data collection and effective Monitoring, Control and Surveillance (MCS). Here we present a novel protocol to collect eDNA from brine tanks onboard commercial longline vessels to reconstruct catch composition. We collected samples from nine vessels operating out of the Eastern Tuna Billfish Fishery, Australia, validating eDNA results with reliable catch data consisting of seven target and bycatch species. Environmental DNA was highly effective for detecting species retained on vessels without contamination or false positives. For four vessels, logbook data and eDNA were consistent with detections of all species. The remaining vessels detected all species except for rare catches of short-billed spearfish (Tetrapturus angustirostris). Similarities between rank abundance distributions of catch and eDNA reads were observed with logbook data mirrored when eDNA sequences were organised into rank order abundance. The method was effective at identifying highly abundant taxa retained in brine tanks- tuna (Thunnus spp.), swordfish (Xiphias gladius), marlin (Kajijia audax), and Atlantic Pomfret (Brama brama). Further research is required to validate how eDNA and other molecular monitoring tools can be scaled and applied to provide solutions for monitoring challenges in the fisheries sector.

Puzzling parrotfishes: Radiocarbon age validation and updated longevity estimates for western Atlantic species in support of sustainable fisheries management.

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.

The impact of COVID-19 pandemic on the world's major economies: based on a multi-country and multi-sector CGE model.

Objective: To quantitatively assess the impact of COVID-19 pandemic on public health, as well as its economic and social consequences in major economies, which is an international public health concern. The objective is to provide a scientific basis for policy interventions. Subject and methods: This study utilizes a multi-country, multi-sector CGE-COVID-19 model to analyze the repercussions of the pandemic in 2022. The re-search focuses on quantifying the effects of COVID-19 on the macroeconomy and various industry sectors within six economies: the United States, China, the EU, the United Kingdom, Japan, and South Korea. Results: The COVID-19 pandemic shock had the most significant impact on China and the EU, followed by notable effects observed in the United States and the United Kingdom. In contrast, South Korea and Japan experienced relatively minimal effects. The reduction in output caused by the pandemic has affected major economies in multiple sectors, including real industries such as forestry and fisheries, and the services such as hotels and restaurants. Conclusion: The overall negative macroeconomic impact of the epidemic on major economies has been significant. Strategic interventions encompassing initiatives like augmenting capital supply, diminishing corporate taxes and fees, offering individual subsidies, and nurturing international cooperation held the potential to mitigate the detrimental economic consequences and enhance the global-economic amid the pan-demic. Consequently, this study contributes to the advancement of global anti-epidemic policies targeting economic recovery. Moreover, using the CGE-COVID-19 model has enriched the exploration of general equilibrium models in PHEIC events.

Determinants of fishing grounds footprint: Evidence from dynamic spatial Durbin model.

Despite a growing literature on fishing grounds footprint, there is no study analyzing fishing footprint regarding spatial effects between neighboring countries. Thus, we explored whether the fishing grounds footprint of 156 countries is spatially correlated. For this purpose, we applied the dynamic spatial Durbin model to examine the direct and indirect effects of GDP per capita, biological capacity, trade openness, population, and urbanization on fishing grounds footprint in the short-term and the long-term during 2001-2021. The results revealed that: (1) there exists a positive and significant spatial dependence in fishing grounds footprint between countries; (2) inverted U-shaped environmental Kuznets curve hypothesis is valid in the short-term and the long-term; (3) fishing grounds footprint is negatively influenced by biocapacity and urbanization in neighboring countries, while population directly increases the fishing footprint. Finally, some suggestions were put forward to reduce fishing grounds footprint and to achieve a sustainable fisheries environment.

Arctic puzzle: Pioneering a northern shrimp (Pandalus borealis) habitat model in Disko Bay, West Greenland.

Recent advancements in spatial modelling leverage remote sensing data and statistical species-environment relationships to forecast the distribution of a specific species. Our study focuses on Disko Bay in West Greenland, recognized as a significant marine biodiversity hotspot in the region. We conducted comprehensive analyses using multiple datasets spanning from 2010 to 2019, incorporating shrimp and fish surveys, commercial shrimp fishery catches, high-resolution (25 × 25 m) multibeam bathymetry and backscatter data along with a medium-resolution (200 × 200 m) bathymetric model, measured and modelled oceanographic data, and satellite chlorophyll data. Through multivariate regression analysis, we tested the significance of various physical factors (seafloor depth, sediment class, bottom water temperature, bottom water salinity, bottom current velocity, space, and time), biological factors (chlorophyll a, Greenland halibut (Reinhardtius hippoglossoides)), and anthropogenic impact (shrimp fishery; standardized catch per unit effort) on the density of northern shrimp in the area. Our results indicate a significant association between northern shrimp density, seafloor depth, and sediment class, explaining 36 % of the variation in shrimp density. Subsequently, we developed a high-resolution (optimized) spatial linear mixed-effect model to map the distribution of northern shrimp across Disko Bay, representing the first model of its kind developed for an Arctic area. The optimal habitat for northern shrimp is characterized by medium-deep waters (approximately 150-350 m), turbulent conditions, and mixed sediments, predominantly located in the northern and southern regions of Disko Bay. Notably, the northern region hosts a relatively diverse benthic community, with northern shrimp and sponges as the primary contributors of epibenthic biomass. This novel high-resolution model significantly enhances our understanding of the physical drivers and detailed spatial patterns influencing the distribution of northern shrimp in the Arctic.

Dropping a bombshell: Acoustic characterization of blast fishing in Todos os Santos Bay, Brazil, and its implication for marine conservation.

Blast fishing is an illegal fishing method that not only affects fish populations and the marine ecosystem, but also local food security and local economy. Despite its effects, blast fishing continues to persist in many coastal regions around the world, including Todos os Santos Bay (BTS - Baia de Todos os Santos) in Northeastern Brazil. This study provides the first acoustic record of underwater explosions along this region. The acoustic data were collected between 2016 and 2018, from a boat-survey platform, using a portable system consisting of an HTI-90 min hydrophone (sensitivity of about -165 dB re 1 V/µPa) connected to a TASCAM DR-40 digital recorder (combined frequency response up to 30 kHz), recording at 7 m depth. The acoustic analysis was performed using both RAVEN 1.6 and MATLAB 2021a softwares. The results revealed a distinctive underwater explosion signal detected in the BTS, indicating evidence of blast fishing activities. The acoustic characterization of blast fishing in BTS provides crucial information on its occurrence and extent of this destructive practice worldwide.

Incorporation of abandoned and lost fishing gear into the structure of Dendrophyllia ramea in the Atlantic coast of Portugal.

Plastic pollution poses global and societal concerns, especially from discarded fishing gear, threatening seabed environments like coral reefs. This study examines the incorporation of lost and/or abandoned fishing gear - specifically synthetic lines, and filaments - into the structure of orange tree coral, Dendrophyllia ramea along the coast of Portugal, in the North-East Atlantic Ocean. The specimens were inadvertently captured by local fishers (Sines and Cascais), with 6 % showing filaments inside their structure, raising questions about their potential impact on coral health. We discuss the implications of understanding the interactions between plastics, fishing gear, and corals, which is important for developing conservation strategies. We address the need for improved of measures aimed at reducing the impact of fishing gear on corals, emphasizing the importance of endorsing biodegradable fishing materials and supporting lost gear retrieval initiatives. Furthermore, we emphasize the urgent need to communicate these issues to both fishers and stakeholders.

Microplastic and other anthropogenic microparticles in Arctic char (Salvelinus alpinus) and their coastal habitat: A first-look at a central Canadian Arctic commercial fishery.

In the recent monitoring guidelines released by the Arctic Monitoring and Assessment Program's Litter and Microplastic Expert Group, Arctic salmonids were recommended as an important species for monitoring plastics in Arctic ecosystems, with an emphasis on aligning microplastic sampling and analysis methods in Arctic fishes. This recommendation was based on the minimal documentation of microplastics in Northern fishes, especially Arctic salmonids. In response, we worked collaboratively with local partners to quantify and characterize microplastics in Arctic char, Salvelinus alpinus, and their habitats in a commercial fishery near Iqaluktuuttiaq (Cambridge Bay), Nunavut. We sampled Arctic char, surface water, and benthic sediments within their summer foraging habitat at Palik (Byron Bay). We found microplastics in 95 % of char with an average of 26 (SD ± 19) particles per individual. On average, surface water samples had 23 (SD ± 12) particles/L and benthic sediment <1 particles/gww. This is the first documentation of plastic pollution in Arctic char and their coastal habitats. Future work should evaluate seasonal, temporal and spatial trends for long-term monitoring of microplastics in Arctic fishes and their habitats.