Spatial distribution of the sport fishing in the state of Amazonas, northern Brazil.

The objective of this study was to spatialize sport fishing operations and assess the frequency of the use of the fishing areas in the state of Amazonas by combining the Geographic Information System (GIS) approach and information available in the documents sent to the Instituto de Proteção Ambiental do Amazonas (IPAAM). Information on sport fishing tourism operations was gathered from the IPAAM database and fishing licenses (FLs). Data analysis was conducted utilizing descriptive analysis, and the spatialization of the locations was performed using Q-GIS software. From 2002 to August 2021, 163 requests for FLs were made. There was a decrease in the amount of first time FL requests, with a peak in 2018 and 2019, N=17 and N=18, respectively. The activity is conducted in 24 municipalities, with Barcelos (31.36%) and Presidente Figueiredo (17.75%) being the most popular. At the sub-basin level, sport fishing is notably present in the Negro, Amazonas, Aripuanã, Madeira, Purus and Solimões River basins. Overall, 26.38% of operations take place in conservation areas, specifically in sustainable development reserves (SDRs). Barcelos recorded the largest number of rivers used, with 15 rivers. These results can support future proposals for the sustainable management of fisheries through the zoning of fishing areas in the state of Amazonas.

A practical approach to meeting national obligations for sustainable trade under CITES.

Reconciling conservation goals with sustainable resource use requires adaptive management strategies. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) regulates global trade for species listed on Appendix II, partly by requiring member countries (parties) to ensure exports do not damage wild populations (called making positive "nondetriment findings" [NDFs]). Unfortunately, when parties find NDFs difficult, they often suspend legal trade, imposing economic costs and driving trade underground. To make it easier for parties to examine the detrimental nature of exports, we devised a spatial approach and applied it to seahorses (Hippocampus spp.) in Tamil Nadu, India, as an example. Our approach involves mapping answers to 5 key questions on species distribution (QA), pressures (QB), management measures (QC), management implementation (QD), and species' population status (QE). We gathered data from fisher interviews and published literature. Seahorse abundance was greatest in southern Palk Bay and the northern Gulf of Mannar, primarily in seagrasses and coral reefs (QA). Fishing pressure was highest in Palk Bay, primarily from bottom trawlers and dragnetters operating in shallow seahorse habitats near the coastline (QB). Management measures including a marine protected area (MPA), bottom trawl exclusion zone, and closed season were theoretically in place (QC), but their implementation was poor (QD). Fishers reported seahorse catches in 85% of the area covered by the MPA and the exclusion zone; bottom trawlers were responsible for most violations. Seahorses were also captured in Sri Lankan waters, where bottom trawling is banned. Fisher reports indicated declining seahorse catches and reduced body sizes (QE), highlighting unsustainable exploitation. Our results highlight the need for better implementation of existing management measures before a positive NDF can be made and suggest mitigation beyond bans. Such pragmatic spatial analyses can help regulate exports at sustainable levels, supporting CITES implementation for its vast range of species.

Un enfoque práctico para cumplir las obligaciones nacionales para el mercado sustentable bajo CITES Resumen Conciliar los objetivos de conservación con el uso sostenible de los recursos exige estrategias de gestión adaptativa. La Convención sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres (CITES) regula el comercio mundial de las especies incluidas en el Apéndice II, en parte exigiendo a los países miembros (partes) que garanticen que las exportaciones no perjudiquen a las poblaciones silvestres (lo que se conoce como dictámenes de extracción no perjudicial [DENP] positivos). Desgraciadamente, cuando las partes encuentran dificultades para formular DENP, a menudo suspenden el comercio legal, lo que impone costos económicos y lleva al comercio a la clandestinidad. Para facilitar a las partes el examen del carácter perjudicial de las exportaciones, ideamos un enfoque espacial y lo aplicamos a los caballitos de mar (Hippocampus spp.) en Tamil Nadu, India, como un ejemplo. Nuestro planteamiento consiste en responder cinco preguntas clave sobre la distribución de las especies (PA), las presiones (PB), las medidas de gestión (PC), la aplicación de la gestión (PD) y el estado de la población de las especies (PE). Se recopilaron datos de entrevistas con pescadores y de la bibliografía publicada. La abundancia de caballitos de mar era mayor en el sur de la bahía Palk y el norte del Golfo de Mannar, principalmente en las praderas marinas y los arrecifes de coral (QA). La presión pesquera era mayor en la bahía Palk, principalmente por parte de redes de arrastre de fondo y redes de arrastre que operaban en hábitats poco profundos de caballitos de mar cerca de la costa (QB). En teoría existían medidas de gestión, como un área marina protegida (AMP), una zona de exclusión para las redes de arrastre de fondo y una temporada de veda (QC), pero su aplicación era deficiente (QD). Los pescadores reportaron capturas de caballitos de mar en el 85% del área cubierta por el AMP y la zona de exclusión; las redes de arrastre de fondo fueron responsables de la mayoría de las infracciones. También se capturaron hipocampos en aguas de Sri Lanka, donde está prohibida la pesca de arrastre de fondo. Los informes de los pescadores indicaron una disminución de las capturas de caballitos de mar y una reducción del tamaño corporal (QE), lo que expone una explotación insostenible. Nuestros resultados resaltan la necesidad de aplicar mejor las medidas de gestión existentes antes de poder hacer un DENP positivo y sugieren medidas de mitigación más allá de las prohibiciones. Estos análisis espaciales pragmáticos pueden ayudar a regular las exportaciones a niveles sostenibles, apoyando la aplicación para la amplia gama de especies de la CITES.

An assessment of potential interventions to reduce the totoaba illegal trade market.

The illegal trade in totoaba (Totoaba macdonaldi) is causing adverse social, ecological, and economic impacts. This illegal activity is accelerating the overexploitation of totoaba and pushing the critically endangered vaquita (Phocoena sinus) closer to extinction. Despite extensive efforts to recover vaquita populations, scant attention has been given to the totoaba trade as an independent issue. As a result, data on the totoaba trade are limited, which hampers robust analyses and development of effective interventions to reduce illegal harvesting. We used a previously developed framework specifically designed to examine dynamics of illegal markets and guide measures to mitigate illegal use of totoaba. This framework separates markets into 3 analytical levels: characterization of participating actors (e.g., fishers, intermediaries); examination of how actors interact within the market (e.g., organization of supply chains); and assessment of the overall market dynamics that result from these interactions (e.g., factors determining price and quantity). We reviewed existing literature (108 initial articles) and interviewed key market actors, academics, and nongovernmental organization experts (14) to obtain data for this framework. Our findings offer an overview of the totoaba illegal market operation, highlighting intervention points (e.g., customs agents) and areas where additional information is required to decrease information gaps (e.g., US local market). We describe the structure and complexity of this market, emphasizing the influential role of organized crime in shaping its dynamics (e.g., controlling prices paid to fishers and stockpiling). By providing a systematic and in-depth understanding of the market operation, we aimed to establish a benchmark for effective interventions and future research aimed at reducing uncertainties. Our results provide a crucial step toward addressing this critical issue and can help facilitate development of effective strategies to combat the illegal totoaba trade and promote biodiversity conservation more broadly.

Evaluación de las intervenciones potenciales para reducir el mercado ilegal de la totoaba Resumen El mercado ilegal de totoaba (Totoaba macdonaldi) causa impactos sociales, ecológicos y económicos adversos. Esta actividad ilegal acelera la sobreexplotación de la totoaba y acerca a la extinción a la vaquita marina (Phocoena sinus), especie en peligro crítico de extinción. A pesar de los grandes esfuerzos por recuperar las poblaciones de vaquita, el comercio de totoaba recibe poca atención como problema independiente. Como resultado, los datos sobre este comercio son limitados, lo que dificulta el análisis sólido y el desarrollo de intervenciones eficaces para reducir la captura ilegal. Utilizamos un marco desarrollado previamente y diseñado específicamente para examinar la dinámica de los mercados ilegales y orientar las medidas para mitigar el uso ilegal de la totoaba. Este marco separa los mercados en tres niveles analíticos: caracterización de los actores participantes (por ejemplo, pescadores, intermediarios); análisis de cómo interactúan los actores dentro del mercado (por ejemplo, organización de las cadenas de suministro); y evaluación de la dinámica general del mercado que resulta de estas interacciones (por ejemplo, factores que determinan el precio y la cantidad). Revisamos la bibliografía existente (108 artículos iniciales) y entrevistamos a actores clave del mercado, académicos y expertos de organizaciones no gubernamentales (14) para obtener datos para este marco. Nuestras conclusiones ofrecen una visión general del funcionamiento del mercado ilegal de totoaba y destacan los puntos de intervención (por ejemplo, los agentes aduanales) y las áreas en las que se requiere información adicional para reducir los vacíos informativos (por ejemplo, el mercado local estadunidense). Describimos la estructura y complejidad de este mercado, destacando el influyente papel de la delincuencia organizada en la configuración de su dinámica (por ejemplo, controlando los precios pagados a los pescadores y el almacenamiento). Al proporcionar una comprensión sistemática y en profundidad del funcionamiento del mercado, pretendemos establecer un punto de referencia para intervenciones eficaces y futuras investigaciones encaminadas a reducir las incertidumbres. Nuestros resultados suponen un paso crucial para abordar esta cuestión crítica y pueden ayudar a facilitar el desarrollo de estrategias eficaces para combatir el comercio ilegal de totoaba y promover la conservación de la biodiversidad de forma más amplia.

Challenges of regulating commercial use of marine elapid snakes in the Indo-Pacific.

Marine elapid snakes are a diverse, predominantly Indo-West Pacific species group. The persistent removal of some species has an unquantified but potentially dire impact on populations. We conducted the first comprehensive review of the trade in marine elapid snakes based on published literature (1974-2022) and trade data from the only species (i.e., Hydrophis [Lapemis] curtus) whose trade is monitored internationally. Some species and populations were subjected to targeted harvest for their meat and skins for at least the last century; fisheries are possibly the most significant threat to populations of marine elapids, with the highest numbers being exploited either accidentally, incidentally, or opportunistically in Southeast Asian fisheries targeting other seafood, including demersal trawl and squid fisheries. Southeast Asia is the core region for exploitation of marine elapids. Annual offtake is >225,000 individuals of at least 8 species in the Gulf of Thailand. Of 72 recognized marine elapids (all non-CITES [Convention on International Trade in Endangered Species of Wild Fauna and Flora] species), Hydrophis curtus and Hydrophis cyanocinctus dominate the skin trade. Skins of H. curtus are traded mainly in East and Southeast Asia and, to some extent, Europe. Despite some baseline information on the trade of these species, the sustainability of their harvests, particularly in the context of the burgeoning and unmanaged nature of fisheries in the region, remains the major challenge. In an era of declining fish stocks, there has been an increasing trend to commercialize the harvest and use marine elapids that were once considered accidental bycatch and discarded. This trend will continue to pose a significant risk to these snakes unless appropriate fisheries and trade regulations are enforced. Applying the precautionary principle to prevent the overexploitation of sea snakes is an indispensable measure in which trade in regional populations should be regulated through CITES. Accordingly, management plans to identify core distribution regions of exploited species would be crucial for assigning national responsibilities to sustain species and populations in the long term.

Retos para la regulación del uso comercial de serpientes elápidas marinas en el Indo­Pacífico Resumen Las serpientes elápidas marinas son un grupo diverso de especies, predominante en el Indo­Pacífico Occidental. La eliminación persistente de algunas especies tiene un impacto no cuantificado pero potencialmente negativo sobre las poblaciones. Realizamos la primera revisión exhaustiva del comercio de serpientes elápidas marinas con base en la bibliografía publicada (1974­2022) y en los datos comerciales de la única especie (Hydrophis [Lapemis] curtus) cuyo mercado tiene monitoreo internacional. Algunas especies y poblaciones fueron objeto de capturas selectivas por su carne y pieles durante al menos el siglo pasado, las pesquerías son posiblemente la amenaza más importante para las poblaciones de elápidos marinos, ya que el mayor número se explota de forma accidental, incidental u oportunista en las pesquerías del sudeste asiático enfocadas en otros mariscos, incluidas las pesquerías demersales de arrastre y de calamar. El sudeste asiático es la principal región de explotación de elápidos marinos. La captura anual es >225,000 individuos de al menos ocho especies en el Golfo de Tailandia. De los 72 elápidos marinos reconocidos (ninguna especie está en CITES [Convención sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres]), Hydrophis curtus e H. cyanocinctus dominan el mercado de pieles. La piel de H. curtus se comercializa principalemnte en el este y sudeste asiático y, hasta cierto punto, en Europa. Aunque se dispone de cierta información de referencia sobre el comercio de estas especies, la sostenibilidad de sus capturas, sobre todo en el contexto del auge y la falta de gestión de la pesca en la región, sigue siendo el principal reto. En una época de disminución de las poblaciones de peces, ha aumentado la tendencia a comercializar la captura y el uso de elápidos marinos que antes se consideraban capturas accidentales y se descartaban. Esta tendencia seguirá representando un riesgo importante para estas serpientes a menos que se apliquen las regulaciones pesqueras y comerciales adecuadas. La aplicación del principio de precaución para evitar la sobreexplotación de las serpientes marinas es una medida indispensable para regular el comercio de las poblaciones regionales a través de CITES. Por lo tanto, los planes de gestión para identificar las regiones núcleo de distribución de las especies explotadas serían cruciales para asignar responsabilidades nacionales para mantener las especies y las poblaciones a largo plazo.

Overfishing and climate change elevate extinction risk of endemic sharks and rays in the southwest Indian Ocean hotspot.

Here, we summarise the extinction risk of the sharks and rays endemic to coastal, shelf, and slope waters of the southwest Indian Ocean and adjacent waters (SWIO+, Namibia to Kenya, including SWIO islands). This region is a hotspot of endemic and evolutionarily distinct sharks and rays. Nearly one-fifth (n = 13 of 70, 18.6%) of endemic sharks and rays are threatened, of these: one is Critically Endangered, five are Endangered, and seven are Vulnerable. A further seven (10.0%) are Near Threatened, 33 (47.1%) are Least Concern, and 17 (24.3%) are Data Deficient. While the primary threat is overfishing, there are the first signs that climate change is contributing to elevated extinction risk through habitat reduction and inshore distributional shifts. By backcasting their status, few endemic species were threatened in 1980, but this changed soon after the emergence of targeted shark and ray fisheries. South Africa has the highest national conservation responsibility, followed by Mozambique and Madagascar. Yet, while fisheries management and enforcement have improved in South Africa over recent decades, substantial improvements are urgently needed elsewhere. To avoid extinction and ensure robust populations of the region's endemic sharks and rays and maintain ecosystem functionality, there is an urgent need for the strict protection of Critically Endangered and Endangered species and sustainable management of Vulnerable, Near Threatened, and Least Concern species, underpinned by species-level data collection and reduction of incidental catch.

Leveraging deep learning and computer vision technologies to enhance management of coastal fisheries in the Pacific region.

This paper presents the design and development of a coastal fisheries monitoring system that harnesses artificial intelligence technologies. Application of the system across the Pacific region promises to revolutionize coastal fisheries management. The program is built on a centralized, cloud-based monitoring system to automate data extraction and analysis processes. The system leverages YoloV4, OpenCV, and ResNet101 to extract information from images of fish and invertebrates collected as part of in-country monitoring programs overseen by national fisheries authorities. As of December 2023, the system has facilitated automated identification of over six hundred nearshore finfish species, and automated length and weight measurements of more than 80,000 specimens across the Pacific. The system integrates other key fisheries monitoring data such as catch rates, fishing locations and habitats, volumes, pricing, and market characteristics. The collection of these metrics supports much needed rapid fishery assessments. The system's co-development with national fisheries authorities and the geographic extent of its application enables capacity development and broader local inclusion of fishing communities in fisheries management. In doing so, the system empowers fishers to work with fisheries authorities to enable data-informed decision-making for more effective adaptive fisheries management. The system overcomes historically entrenched technical and financial barriers in fisheries management in many Pacific island communities.

Molecular identification of Mymarothecium viatorum and Anacanthorus penilabiatus in extensive native fish farming systems of the Peruvian Amazon.

Piaractus brachypomus (Pacú) is the main native fish species cultivated in Peru and holds great potential for growth in aquaculture from the Peruvian Amazon. Between October 2021 and January 2022 in two fish producing farms in the Amazon region of San Martín in Peru, P. brachypomus individuals were examined for parasite evaluation. A total of 6366 monogeneans were isolated from the gills of 30 fish, revealing a prevalence of 100%, with an abundance and mean intensity of 212 parasites per fish. Monogeneans were morphologically identified as Mymarothecium viatorum and Anacanthorus penilabiatus. The genetic divergence in the 28S rDNA gene found among A. penilabiatus sequences was 0.1% and among Anacanthorus spp. it ranged from 0.9% to 7.5%. The genetic divergence found among the M. viatorum sequences was 0.3%. These finding represents the first molecular data of M. viatorum and A. penilabiatus in Peru using the 28S rDNA gene of these monogeneans. The new sequences obtained will contribute to future studies on the phylogenetic relationships among dactylogyrids. However, further research with a broader range of host-parasite samples and additional genetic markers is needed to clarify these relationships and provide stronger support for the phylogenetic positions.

Whale recovery and the emerging human-wildlife conflict over Antarctic krill.

The Southern Ocean ecosystem has undergone extensive changes in the past two centuries driven by industrial sealing and whaling, climate change and commercial fishing. However, following the end of commercial whaling, some populations of whales in this region are recovering. Baleen whales are reliant on Antarctic krill, which is also the largest Southern Ocean fishery. Since 1993, krill catch has increased fourfold, buoyed by nutritional supplement and aquaculture industries. In this Perspective, we approximate baleen whale consumption of Antarctic krill before and after whaling to examine if the ecosystem can support both humans and whales as krill predators. Our back-of-the-envelope calculations suggest that current krill biomass cannot support both an expanding krill fishery and the recovery of whale populations to pre-whaling sizes, highlighting an emerging human-wildlife conflict. We then provide recommendations for enhancing sustainability in this region by reducing encounters with whales and bolstering the krill population.

Lumpfish, Cyclopterus lumpus, distribution in the Gulf of Maine, USA: observations from fisheries independent and dependent catch data.

The Gulf of Maine (GoM) is one of the fastest-warming parts of the world's oceans. Some species' distributional shifts have already been documented, especially for commercially-important species. Less is known about species that are not currently exploited but may become so in the future. As a case study into these issues, we focus on lumpfish (Cyclopterus lumpus) because of the recognized and timely need to understand wild lumpfish population dynamics to support sustainable fisheries and aquaculture developments. Using occurrence data from five different fisheries-dependent and independent surveys, we examined lumpfish distribution over time in the GoM. We found that lumpfish presence was more likely in Fall and correlated with deeper waters and colder bottom temperatures. Since 1980, lumpfish presence has increased over time and shifted north. Given a limited set of data, these findings should be interpreted with caution as additional work is needed to assess if the actual distribution of lumpfish is changing. Nevertheless, our work provides preliminary information for resource managers to ensure that lumpfish are harvested sustainably for use in emergent lumpfish aquaculture facilities.

Stock assessment models overstate sustainability of the world's fisheries.

Effective fisheries management requires accurate estimates of stock biomass and trends; yet, assumptions in stock assessment models generate high levels of uncertainty and error. For 230 fisheries worldwide, we contrasted stock biomass estimates at the time of assessment with updated hindcast estimates modeled for the same year in later assessments to evaluate systematic over- or underestimation. For stocks that were overfished, low value, or located in regions with rising temperatures, historical biomass estimates were generally overstated compared with updated assessments. Moreover, rising trends reported for overfished stocks were often inaccurate. With consideration of bias identified retrospectively, 85% more stocks than currently recognized have likely collapsed below 10% of maximum historical biomass. The high uncertainty and bias in modeled stock estimates warrants much greater precaution by managers.

Taking stock of global fisheries.

Current stock assessment models overestimate productivity and recovery trajectory.

Twenty-five emerging questions when detecting, understanding, and predicting future fish distributions in a changing climate.

The 2023 Annual Symposium of the Fisheries Society of the British Isles hosted opportunities for researchers, scientists, and policy makers to reflect on the state of art of predicting fish distributions and consider the implications to the marine and aquatic environments of a changing climate. The outcome of one special interest group at the Symposium was a collection of questions, organized under five themes, which begin to capture the state of the field and identify priorities for research and management over the coming years. The five themes were Physiology, Mechanisms, Detect and Measure, Manage, and Wider Ecosystems. The questions, 25 of them, addressed concepts which remain poorly understood, are data deficient, and/or are likely to be impacted in measurable or profound ways by climate change. Moving from the first to the last theme, the questions expanded in the scope of their considerations, from specific processes within the individual to ecosystem-wide impacts, but no one question is bigger than any other: each is important in detecting, understanding, and predicting fish distributions, and each will be impacted by an aspect of climate change. In this way, our questions, particularly those concerning unknown mechanisms and data deficiencies, aimed to offer a guide to other researchers, managers, and policy makers in the prioritization of future work as a changing climate is expected to have complex and disperse impacts on fish populations and distributions that will require a coordinated effort to address.

The evolution of aquaculture in the Mediterranean region: An anthropogenic climax stage?

This study is the investigation of Mediterranean aquaculture complete history, from 1950 to 2020. Both functional than geographical expansion of aquaculture is investigated, considering two main complementary aspects of aquaculture: farmed species and farming countries. According to the models proposed in this research, Nile tilapia and Egypt will dominate the future of Mediterranean aquaculture. Malta and Israel are the first producer countries, in relative terms. The most pervasive species are European sea bass and gilthead sea bream that are promising for a future expansion. In several countries, aquaculture has huge potentiality of development and it could grow with a factor of 5 or more, based on the ratio capture vs fishery on country size. Aquaculture total production in 2020 was of 2.8 Mln tons and it is expected to reach from 3.65 Mln tons in 2030. Aquaculture will grow in the countries and species that in this moment are dominant and the future of Mediterranean aquaculture will be characterized by the affirmation of these ones.

Is it worthy to use environmental DNA instead of scientific trawling or video survey to monitor taxa in soft-bottom habitats?

Non-extractive techniques such as video analysis are increasingly used by scientists to study marine communities instead of extractive methods such as trawling. Currently, environmental DNA (eDNA) analysis is seen as a revolutionary tool to study taxonomic diversity. We aimed to determine which method is the most appropriate to describe fish and commercial invertebrate diversity comparing bottom trawl hauls, video transects and seawater eDNA. Our results reveal that video detected the lowest number of taxa and trawling the highest. eDNA analysis is powerful to describe marine bony fish communities, but some taxa of importance for the ecosystem such as elasmobranchs, crustaceans or molluscs are poorly detected. This may be due to several factors such as marker specificity, incomplete reference gene databases or low DNA release in the environment. For now, the various methods provide different information and none is exhaustive enough to be used alone for biodiversity characterisation.

Risk of capture is modified by hypoxia and interjurisdictional migration of Lake Whitefish (Coregonus clupeaformis).

Interjurisdictional migrations lead to seasonally changing patterns of exploitation risk, emphasizing the importance of spatially explicit approaches to fishery management. Understanding how risk changes along a migration route supports time-area based fishery management, but quantifying risk can be complicated when multiple fishing methods are geographically segregated and when bycatch species are considered. Further, habitat selection in dynamic environments can influence migration behavior, interacting with other management objectives such as water quality and habitat restoration. As a case study, we examined a novel acoustic telemetry data set for Lake Whitefish in Lake Erie, where they migrate through multiple spatial management units that are variably affected by seasonal hypoxia and host a variety of fisheries. Combining telemetry results with fishery catch and water quality monitoring, we demonstrate three exploitation risk scenarios: (i) high risk due to high residency and high catch, (ii) high risk due to high residency in time-areas with moderate catch, and (iii) low risk due to residency in time-areas with low catch. Interestingly, occupation of low risk refugia was increased by the development of hypoxia in adjacent areas. Consequently, fishery management goals to sustainably manage other target species may be directly and indirectly linked to water quality management goals through Lake Whitefish.

Do risk-prone behaviours compromise reproduction and increase vulnerability of fish aggregations exposed to fishing?

Human disturbances can prompt natural anti-predator behaviours in animals, affecting how energy is traded off between immediate survival and reproduction. In our study of male squaretail groupers (Plectropomus areolatus) in India's Lakshadweep archipelago, we investigated the impact of fishing pressure on anti-predatory responses and reproductive behaviours by comparing a fished and unfished spawning aggregation site and tracking responses over time at the fished site. Using observational sampling and predator exposure experiments, we analysed fear responses (flight initiation distance, return time), as well as time spent in vigilance, courtship and territorial defence. Unpaired males at fished sites were twice as likely to flee from simulated predators and took longer to return to mating territories. In contrast, paired males at both sites took greater risks during courtship, fleeing later than unpaired males, but returned earlier at the unfished site compared with the fished site. Our findings suggest that high fishing pressure reduces reproductive opportunities by increasing vigilance and compromising territorial defence, potentially affecting mate selection cues. Altered behavioural trade-offs may mitigate short-term capture risk but endanger long-term population survival through altered reproductive investment. Human extractive practices targeting animal reproductive aggregations can have disruptive effects beyond direct removal, influencing animal behaviours crucial for population survival.

Marine Fish Movement: home range sizes for commercially relevant species.

Estimates of home range sizes for marine fishes are essential for designing and assessing the effects of spatial wildlife conservation policies and management interventions. However, in situ studies of marine species movement are challenging and often expensive, resulting in a paucity of data on the home range size of the vast majority of marine fishes. Here, we develop a set of new datasets, which we have collectively named Marine Fish Movement, that synthesises published empirically evaluated home ranges reported for adult marine fishes that interact with fisheries and leverage these data to estimate home range sizes for unstudied species. The empirical data contain estimated home range sizes (km2) for 193 species across 63 family groups from 179 studies published between 1971 and 2022. We use a random forest regression model to estimate home range sizes (km2) for 664 fished marine species currently lacking home range estimates. Marine Fish Movement can inform spatial interventions including the design and management of marine protected areas and dynamic fisheries management to meet sustainability goals.

Integrating the water-energy-food nexus and LCA + DEA methodology for sustainable fisheries management: A case study of Cantabrian fishing fleets.

The fishing sector constitutes an important source of economic revenue in northern Spain. In this context, various research studies have focused on the application of the five-step Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) methodology to quantify environmental impacts of fishing systems. However, some of them have used environmental indicators that focus on individual environmental issues, hindering the goal of achieving integrated resource management. Therefore, in this study, the Water-Energy-Food (WEF) Nexus is employed as an integrative perspective that considers the synergies and trade-offs between carbon footprint, energy requirements, and water demand. The main objective of this study is to evaluate the operational efficiency and environmental impacts of Cantabrian fishing fleets. To this end, the combined use of LCA and DEA, along with the WEF Nexus, was applied to the Cantabrian purse seine fleet. DEA matrices were generated using the LCA-derived WEF nexus values as inputs to calculate efficiency scores for each vessel. Subsequently, based on the efficiency projections provided by the DEA model, a new impact assessment was performed to understand the eco-efficiency and potential environmental benefits of operating at higher levels of efficiency within this fleet. The average efficiency of the fleet was above 60 %. Inefficient units demonstrated a greater potential to reduce their environmental impacts (up to 65 %) by operating according to efficiency projections. Furthermore, the results revealed a strong dependence of environmental impacts on one of the operational inputs, i.e., fuel consumption. These findings highlight the significance of embracing holistic approaches that combine technical, economic, and social factors to achieve a sustainable balance in fisheries systems. In this regard, the five-step LCA + DEA method applied in conjunction with the WEF Nexus emerged as a suitable tool for measuring operational and environmental objectives.

Isolation of Lactic Acid Bacteria Eliminating Trimethylamine (TMA) for Application to Fishery Processing.

Fishy odor of fish flesh (meat) presents a severe problem for marine production. The main cause of fishy odor is trimethylamine (TMA), which increases during storage. It is produced from trimethylamine oxide (TMAO), an osmosis-regulating substance in fish cells that functions by a reduction reaction. Bacterial growth in fish meat increases TMA. Its odor reduces the commercial value of the meat. Technologies for its regulation and elimination are desired. This chapter presents a description of the use of lactic acid to eliminate TMA. The lactic acid is producible safely by bacteria during food processing using picric acid-toluene.A method of eliminating TMA was demonstrated using Lactobacillus plantarum H78. Furthermore, an assay method was explained for reducing TMA in fish meat by fermenting the H78 strain.

The global extent and severity of operational interactions between conflicting pinnipeds and fisheries.

Recent population recovery of many pinniped species (seals, sea lions, walrus) is a conservation success. However, pinniped population recovery combined with increasing global fisheries operations is leading to increased conflicts between pinnipeds and fisheries. This human-wildlife conflict threatens pinniped conservation outcomes and may impose damaging impacts on fisheries, but the economic consequences and extent of these impacts are poorly understood. Here, we provide a global assessment of pinniped and fisheries operational interactions. We show that a third of reported fishing days have interactions with pinnipeds and 13.8% of catch is lost. Our results also reveal high heterogeneity between studies. Small-scale fisheries are three times more likely to interact with pinnipeds and lose four times as much catch as large-scale fisheries. Finally, we develop a spatial index that can predict where conflict is most likely to occur. Our findings reveal a substantial global issue requiring appropriate management as pinniped populations continue to recover.