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Between 2009 and 2021 almost the complete beam trawl fleet of the Netherlands switched from conventional beam trawls (BT) to pulse trawls (PT) using electrical stimulation to catch sole, Solea solea. Electric fishing, being banned in the EU in 1988, was made possible in 2006 under a derogation. Over the years stakeholders expressed concern about ecosystem effects. Here we review the research conducted. PT improved the selectivity of the fishery and reduced the ecological side effects. PT caught more sole per hour fishing but less discards and benthos than BT. The transition to PT reduced the surface area swept (lower towing speed), sediment depth of disturbance and associated benthic impacts, as well as fuel consumption. Laboratory experiments with 9 fish and 17 benthic invertebrate species showed that exposure to a commercial bipolar pulse stimulus did not result in harmful effects except in cod. Autopsy of cod sampled from PT revealed that 40% had an internal injury. Injury rates in other roundfish species was low (< 2%) and absent in flatfish. Electrical-induced impacts on biogeochemistry were not observed. The transition increased competition with other fishers which fed the resentment against PT. Governance arrangements under which the number of temporary licenses expanded, undermined legitimacy of the gear, resulting in a ban in 2021. Although questions about the ecological impact of electrical stimulation remain, adverse effects are considered negligible in comparison with the benefits. [ABSTRACT FROM AUTHOR]

The present study aimed to estimate the quantity and composition of discarded fish species in bottom trawl in the Lifeh area of the coastal waters of Khuzestan. Data were collected based on samples obtained from commercial fishing the autumn of 2017 and the summer of 2018. The results of this study indicated that the discarded samples included 21 species from 16 families. Hamilton's thryssa, Sharhosehammer croaker and Orange-fin pony fish species were predominant. Moreover, the results demonstrated that the average length of most discarded species was below 30 centimeters, with the highest average length belonging to the large scale tongues at 3.8±3.23 centimeters and the lowest for the large scale tongues at 8.5±8.10 centimeters. The findings revealed the discard rate per fishing effort unit in autumn as 4.0±6.8 kilograms per hour and in summer as 8.7±2.7 kilograms per hour. The catch per unit area was also calculated at 24.0±16.0 and 7.15±0.0 kilograms per square mile during autumn and summer, respectively. Furthermore, the percentage frequency of commercial and non-commercial discarded species in autumn was calculated as 22.74 and 77.26, respectively, and in summer as 7.7 and 3.92, respectively. Considering the obtained results and the elevated discard rate in this area, it can evidently have negative impacts on fish stocks, potentially posing risks to the fishing industry in the region in the future. [ABSTRACT FROM AUTHOR]

Whiteleg skate (Amblyraja taaf) is a bycatch species commonly discarded in demersal longline fisheries targeting Patagonian toothfish around the Crozet archipelago (Southern Ocean). While there are global conservation issues on elasmobranchs, the post-release survival of this deep-sea species remains unknown. This study is the first tagging programme conducted on Whiteleg skates to investigate their fate after being released at sea. Almost 3000 skates were captured, double-tagged with conventional tags and released between 2020 and 2022 to assess survival using capture–mark–recapture (CMR) models. Our primary result was an estimated annual apparent survival rate higher than 92% for skates released in good condition (with 185 skates recaptured after up to 944 days at liberty). Low detection rate highlighted methodological challenges for CMR models. However, skate size and depth of capture had an effect on apparent survival probability with smaller individuals having lower values (<65 cm; 0.84 ± 0.04) as well as skates caught at shallower depths (<1200 m; 0.83 ± 0.04). Overall, this study suggests that the mandated release of skates in good condition is effective to limit fishing impact on skates in this fishery. To further limit this impact, we recommended changes in fishing practices (hauling speed and soak time). [ABSTRACT FROM AUTHOR]

The valorization of aquaculture/fishery processing by-products, as well as unavoidable/unwanted catches and discards in Greece, is currently an underutilized activity despite the fact that there are several best practices in Northern Europe and overseas. One of the main challenges is to determine whether the available quantities for processing are sufficient to warrant the valorization of discards and fish side streams. This is the first attempt to systematically record and analyze the available quantities of fish by-products and discards in Greece spatially and temporally in an effort to create a national exploitation Master Plan for the valorization of this unavoidable and unwanted biomass. A thorough survey conducted within the VIOAXIOPIO project unveiled a substantial biomass of around 19,000 tonnes annually that could be harnessed for valorization. Furthermore, the production of various High-Added-Value Biomolecules (HAVBs) was investigated and experimental trials were conducted to assess the potential yields, with the collected data used to formulate four valorization scenarios. [ABSTRACT FROM AUTHOR]

Overexploitation in wild-capture fisheries is a principal driver of marine biodiversity loss. Currently, efforts are underway to improve the representation of marine damage indicators in Life Cycle Impact Assessment (LCIA) methods. The recently operationalised fisheries impact pathway has introduced fishing impacts on the marine system into the LCIA framework, and the current work seeks to further develop this complex pathway. In total, 5000+ Characterisation Factors for exploited marine organisms have been re-computed with updated fisheries production data (2018), exploring temporal effects on dynamic, biotic resource impacts. An estimation of discarded unwanted by-catch is incorporated into the characterisation. Regional to global scaling factors are tested for the representation of species-specific vulnerability. The temporal and spatial variations in impacts reflect the dynamic nature of real-world fisheries trends, global average impacts increased by 41% (2015–2018). Discarding as an additive, regional estimate increases impacts, most notably for lower impacted stocks. The retention of species-specific detail relating to species distributions is of particular relevance to fisheries when computing global-scale impacts. Updating CFs improves the relevance of the fisheries impact assessment, and continued periodic re-computation is recommended to maintain relevance with real-world trends. Data availability remains a challenge to large-scale marine impact assessment and the continued development of this emergent impact pathway is expected. [ABSTRACT FROM AUTHOR]

This manuscript explores the role of European anchovies (Engraulis encrasicolus) in the central Mediterranean Region, shedding light on their ecological significance, conservation challenges, and sustainable utilization. The European anchovy is one of Europe's most important fish resources in the Mediterranean basin, and it is considered a keystone species, playing a pivotal role in both ecological and socio-economic dimensions. However, in recent decades, European anchovy, together with Sardina pilchardus (commonly known as European sardine), has suffered a population decline for several reasons. Consequently, it is necessary to improve the management of anchovy fisheries by understanding the reproductive modes and characteristics, the influence of currents on the passive transport of eggs and larvae, the feeding habits, the environmental adaptability (e.g., salinity), and the distribution of ecotypes along the Italian coasts. Such information is fundamental for the management of fisheries, especially artisanal ones, and to control frauds, especially in protected, geographically referred, and traditional high-quality commercial products. Various aspects, ranging from their population dynamics to their industrial processing and the ecological implications of these activities were delved, highlighting the knowledge about anchovy populations and ecotypes and its importance in maintaining ecosystem balance and sustaining human communities. The ecological interaction of anchovies within the food web, as essential data in the conservation actions and management of these resources was emphasized. In addition, the metabolic and stomach contents diversity among anchovy populations and ecotypes was discussed, enhancing our understanding of their adaptability to varying environmental conditions. The manuscript then explores the traditional and industrial processing of anchovies, encompassing aspects ranging from fishing techniques (i.e., methods of capture) to their industrial significance, sustainability concerns, issues of fraud, and the establishment of geographical traceability. Finally, the opportunities for sustainable and biotechnological utilization of anchovy discards were also further explored, demonstrating the potential for waste reduction and resource optimization. [ABSTRACT FROM AUTHOR]

Discards decrease natural resources and harm the viability of fisheries. The current experiment was conducted to determine the suitability of fish discards for cultivating the Nile tilapia (Oreochromis niloticus) and their effect on growth rates and the health condition of the fish. 300 healthy live Nile tilapia specimens were obtained and divided into five equal groups, coded as 0, 25, 50, 75, and 100% DF diets. The experiment lasted for 60 days. All growth performance parameters revealed no discernible difference between fish fed 0 (control group) and 100% DF diets. Fish fed 75% DF diet recorded the best significant feed conversion rate of 1.1± 0.4. Fish fed 50 and 75% DF diets recorded the highest significant weight gain (25.4± 3.02, 25.3± 2.7g, respectively). The glucose value showed a significant decrease in the 25% DF treatment and an increase in 100% DF treatment, while it showed a non-significant decrease in 50 and 75% DF treatments. This study determined that the haematological values remained acceptable for tilapia production. The present work concluded that fish discards are suitable as dietary protein sources for the Nile tilapia; it contributed significantly to fisheries' sustainability and the Nile tilapia feeding cost reduction. [ABSTRACT FROM AUTHOR]

In the Mediterranean, one of the main reasons for discarding commercial species is when fishers catch fish smaller than the minimum conservation reference size (MCRS). In reality though, other drivers that vary by country/region have greater impact on the discarding process. A notable illustration of the coexistence of different motives is the Greek bottom trawl fishery. Present work focused on the spatial analysis of discards of three commercial species subjected to MCRS with low market price and often discarded independent of their size (i.e., Trachurus trachurus, Parapenaeus longirostris, Sardina pilchardus). To model and map the spatial distribution of species discards, hierarchical Bayesian spatial models were utilized employing discards dependence on environmental inputs. Further information was gained, by calculating the spatial overlap between the spatial distribution of species discards and their known nurseries. Results showed that S. pilchardus discards had the highest estimated values in shallower waters, whereas T. trachurus and P. longirostris discards were distributed over greater depths. Only a small portion of species nurseries and discard grounds coincided, verifying that the reasons behind discarding were market-driven. Area-specific and species-specific management is essential to reduce discards, since local market demand and fishing restrictions have an impact on the discarding process. [ABSTRACT FROM AUTHOR]

Otoliths are widely employed in marine sciences to gain insights into fish growth, age, migrations, and population structure. This study investigates the relationships between morphometric measurements, otolith characteristics, and length size patterns in the brown comber (Serranus hepatus) from the Gulf of Cádiz, a species discarded in artisanal trawl fisheries. Our findings reveal significant changes in otolith shape indices as fish grow, with symmetry observed between left and right otolith measurements. Otolith size is found to be related to fish size, supporting its use in estimating body length at different life stages. Otolith shape analysis has potential applications in stock identification, detecting catch misreporting, and studying marine predator diets. Combining otolith shape analysis with other data types can clarify relationships among taxa and inform spatial management strategies, contributing to the long‐term sustainability of fish populations and the assessment of the impact of management strategies on fish size and growth. This study enhances our understanding of the broader implications of morphometric and otolith analyses in fisheries research and supports the development of more sustainable fisheries management practices. [ABSTRACT FROM AUTHOR]

Recently, various state-space implementations of surplus production models (SPMs) have been developed for data-limited stocks. Often, catches and fishing effort are underestimated and discards are ignored. This results in biased estimates of stock status and reference points. Therefore, we conduct a sensitivity analysis for different under-reporting scenarios (due to non-declared landings, by-catch, and discards) on model estimates and thus advice for the black hake species in northwest Africa. Two modelling frameworks were used, namely a stochastic SPM in continuous time (SPiCT) and Just Another Bayesian Biomass Assessment (JABBA). A common set of diagnostics was developed to allow comparison across modelling frameworks. Scenarios correspond to hypotheses about misreporting and assumptions and priors that were kept consistent. The ratio of current fishing mortality over the fishing pressure that gives the maximum sustainable yield, F/FMSY , is most affected by under-reporting. Results are sensitive to the prior assumed for the initial depletion level, B0/K , and research is needed. If the misreporting is changing over time, relative quantities (e.g. F/FMSY) and trends are biased, while if misreporting (or at least a part of misreporting) is constant, relative quantities are unbiased. Therefore, the nature of any trend in misreporting should be investigated. [ABSTRACT FROM AUTHOR]

This manuscript explores the role of European anchovies (Engraulis encrasicolus) in the central Mediterranean Region, shedding light on their ecological significance, conservation challenges, and sustainable utilization. The European anchovy is one of Europe’s most important fish resources in the Mediterranean basin, and it is considered a keystone species, playing a pivotal role in both ecological and socio-economic dimensions. However, in recent decades, European anchovy, together with Sardina pilchardus (commonly known as European sardine), has suffered a population decline for several reasons. Consequently, it is necessary to improve the management of anchovy fisheries by understanding the reproductive modes and characteristics, the influence of currents on the passive transport of eggs and larvae, the feeding habits, the environmental adaptability (e.g., salinity), and the distribution of ecotypes along the Italian coasts. Such information is fundamental for the management of fisheries, especially artisanal ones, and to control frauds, especially in protected, geographically referred, and traditional high-quality commercial products. Various aspects, ranging from their population dynamics to their industrial processing and the ecological implications of these activities were delved, highlighting the knowledge about anchovy populations and ecotypes and its importance in maintaining ecosystem balance and sustaining human communities. The ecological interaction of anchovies within the food web, as essential data in the conservation actions and management of these resources was emphasized. In addition, the metabolic and stomach contents diversity among anchovy populations and ecotypes was discussed, enhancing our understanding of their adaptability to varying environmental conditions. The manuscript then explores the traditional and industrial processing of anchovies, encompassing aspects ranging from fishing techniques (i.e., methods of capture) to their industrial significance, sustainability concerns, issues of fraud, and the establishment of geographical traceability. Finally, the opportunities for sustainable and biotechnological utilization of anchovy discards were also further explored, demonstrating the potential for waste reduction and resource optimization.

Despite anti-finning laws aimed at conserving sharks, Worm et al. have revealed that global shark mortality rates have surprisingly risen over the past decade, driven in large part by increased demand for meat. Here, we discuss the importance of this study, underscoring the need for broader regulations addressing overall shark mortality amid threats from global change. [ABSTRACT FROM AUTHOR]

The valorization of aquaculture/fishery processing by-products, as well as unavoidable/unwanted catches and discards in Greece, is currently an underutilized activity despite the fact that there are several best practices in Northern Europe and overseas. One of the main challenges is to determine whether the available quantities for processing are sufficient to warrant the valorization of discards and fish side streams. This is the first attempt to systematically record and analyze the available quantities of fish by-products and discards in Greece spatially and temporally in an effort to create a national exploitation Master Plan for the valorization of this unavoidable and unwanted biomass. A thorough survey conducted within the VIOAXIOPIO project unveiled a substantial biomass of around 19,000 tonnes annually that could be harnessed for valorization. Furthermore, the production of various High-Added-Value Biomolecules (HAVBs) was investigated and experimental trials were conducted to assess the potential yields, with the collected data used to formulate four valorization scenarios.

Fishing activity generates high amounts of fishing discards, a predictable anthropogenic food subsidies used by seabirds. Although the use of discards by these predators has been well studied, there is a lack of knowledge about the ontogenetic differences in their use. We contributed to filling this gap for the yellow-legged gull (Larus michahellis), an opportunistic predator that extensively exploits anthropogenic food subsides. We investigated its foraging behaviour during the early breeding season deploying GPS devices on adults, immatures, and juveniles from the urban population of Barcelona (northwestern Mediterranean Sea) and examining the effect of fishing vessels on their spatial movements using a Vessel Monitoring System. The results revealed age-related differences in distribution and foraging behaviour at sea and an interaction with fishing vessels in this seabird. Age-related differences in behaviour were explained by the reproductive constraints of adults and the ontogenetic differences associated with lower foraging ability in immature and juvenile individuals. We did not find apparent preferences for a specific type of fishing vessel between ages. These results suggest that the reform of the Common Fisheries Policy might affect the entire population of this species, that could lead to an increase in the use of urban environments, increasing the conflicts with human activities. [ABSTRACT FROM AUTHOR]

Knowledge of fisheries impacts, past and present, is essential for understanding the ecology and conservation of seabirds, but in a rapidly changing world, knowledge and research directions require updating. In this Introduction and in the articles in this Themed Set "Impacts of fishing on seabirds", we update our understanding of how fishing impacts seabird communities and identify areas for future research. Despite awareness of the problems and mitigation efforts for >20 years, fisheries still negatively impact seabirds via the effects of bycatch, competition, and discards. Bycatch continues to kill hundreds of thousands of seabirds annually, with negative population-level consequences. Fisheries for forage fish (e.g. anchovy, sandeel, and krill) negatively impact seabirds by competing for the same stocks. Historically, discards supplemented seabird diets, benefitting some species but also increasing bycatch rates and altering seabird community composition. However, declining discard production has led to potentially deleterious diet switches, but reduced bycatch rates. To improve research into these problems, we make the following recommendations: (1) improve data collection on seabird–vessel interaction and bycatch rates, on fishing effort and vessel movements (especially small-scale fleets), and on mitigation compliance, (2) counter the current bias towards temperate and high-latitude ecosystems, larger-bodied species and particular life stages or times of year (e.g. adults during breeding), and (3) advance our currently poor understanding of combined effects of fisheries and other threats (e.g. climate change, offshore renewables). In addition, research is required on under-studied aspects of fishing impacts: consequences for depleted sub-surface predators, impacts of illegal, unreported and unregulated fishing, artisanal and emerging fisheries, such as those targeting mesopelagic fish, have received insufficient research attention. Some of these shortfalls can be overcome with new tools (e.g. electronic monitoring, remote sensing, artificial intelligence, and big data) but quantifying and addressing fishing impacts on seabirds requires greater research investment at appropriate spatio-temporal scales, and more inclusive dialogue from grassroots to national and international levels to improve governance as fishing industries continue to evolve. [ABSTRACT FROM AUTHOR]

Several Mediterranean fisheries are experiencing flaws in the application of the management system based on input control, including Algeria, where the state of fisheries and stocks remain unclear. This paper focused on the characterization of the catches from bottom trawling by professional fishing vessels in the Mostaganem fishery (West of Algeria). Catch data were collected on board between 2017 and 2020 in two different fishing areas between isobaths 30 and 100 meters in depth. Out of a total of 87 species caught, discards represented a greater variety of species (74) than landings (57). Quantitatively, the landing weights were estimated at 7.8 tons, while the discard weights were lower, accounting for 1.8 tons. Between the two fishing areas, a significant difference was detected in the composition of discards and landings, while for the weights, the two areas were similar. Generally, the Mostaganem fishery is similar to other bottom trawl Mediterranean fisheries both for target and discard species. Otherwise, this research highlighted the existence of an uncontrolled black market, which sustains the practice of illegal, unregulated and unreported fishing, and potentially increases the rate of overexploitation. [ABSTRACT FROM AUTHOR]

The current study aimed to elucidate the capture mechanism of B. brandaris and H. trunculus in two métiers of the Greek small-scale fisheries (SSF) that use trammel. The commercial and discarded catch from three commercial SSF boats was recorded in parallel to in-situ SCUBA diving observations and video analyses of the entangled catch at net retrieval. The abundance of gastropods in the nets was correlated with the abundance of captured fish in both métiers. This correlation was undoubtedly caused by the scavenging activity of gastropods on organisms captured in the lower portion of the net, such as combers, wrasses, and cuttlefish. Underwater observations revealed that the number of scavengers per fish increased gradually with the degree of fish consumption, whereas on-deck observations revealed that the foraging groups became malformed as soon as the flesh consumption was complete, as evidenced by the presence of fish bones in the absence of scavengers. Only a small percentage of the gastropods in the catch became entangled on the net, and that the majority of the gastropods were carried on deck by attaching to their entangled prey. The current study provided a clear explanation of the capture mechanism of the two muricids, as well as critical knowledge for their conservation. [ABSTRACT FROM AUTHOR]

The discarded species caught in prawn trammel nets damage the nets and cause a serious labor loss problem for fishers. In the present study, a 15 cm high greenhouse plastic film and a greenhouse shade cloth net were fitted between the lower parts of the nets and the lead collars to reduce discards in the trammel net fishery. The modified nets were tested in Mersin Bay with twenty-one fishing operations between September and December 2021. The results showed that, compared to commercial trammel nets, the nets equipped with greenhouse plastic film and greenhouse shade cloth did not significantly reduce the catch of the target species green tiger prawn (Penaeus semisulcatus). However, the total number of discards significantly decreased. The discard rates in the commercial net, greenhouse plastic film net, and greenhouse shade cloth net were 45%, 26%, and 22%, respectively. Furthermore, when the incomes from the nets' hauls were calculated, the net equipped with greenhouse garden film and the net equipped with greenhouse shade cloth generated 24.77% and 14.41% more profit than the commercial net, respectively. [ABSTRACT FROM AUTHOR]

Mobile bottom contact gear such as trawls is widely considered to have the highest environmental impact of commonly used fishing gears, with concern about impact on benthic communities, bycatch, and carbon footprint frequently highlighted as much higher than other forms of fishing. As a result, the use of such gears has been banned or severely restricted in some countries, and there are many proposals to implement such restrictions elsewhere. In this paper, we review the sustainability of bottom trawling with respect to target-species sustainability, impact on benthic communities, bycatch and discards, carbon footprint from fuel use, and impact on carbon sequestration. We compare the impact to other forms of fishing and other food production systems. We show that bottom-trawl and dredge fisheries have been sustained, and where well managed, stocks are increasing. Benthic sedimentary habitats remain in good condition where fishing pressure is well managed and where VME and species of concern can be protected by spatial management. Bycatch is intrinsically high because of the mixed-species nature of benthic communities. The carbon footprint is on average higher than chicken or pork, but much less than beef, and can be much lower than chicken or pork. The impact on carbon sequestration remains highly uncertain. Overall, the concerns about trawling impacts can be significantly mitigated when existing technical gear and management measures (e.g. gear design changes and spatial controls) are adopted by industry and regulatory bodies and the race-to-fish eliminated. When these management measures are implemented, it appears that bottom trawling would have a lower environmental impact than livestock or fed aquaculture, which would likely replace trawl-caught fish if trawling was banned. A total of 83 bottom-trawl fisheries are currently certified by the Marine Stewardship Council, which is the most widely accepted measure of overall sustainability. [ABSTRACT FROM AUTHOR]

The Landing Obligation (LO), introduced in 2015 by the Common Fisheries Policy of the European Union (EU-CFP), has been subject to a transitional period until recently. The rationale behind the measure is that all fish species subject to a total allowable catch (TAC) must be landed to increase the sustainability of fishing activities. Through the analysis of official statistical data, it is possible to find out which species of fish were landed and their relative importance, including their monetary value, and verify the potential for consumer acceptance. Some insights are drawn from the interconnection between these three factors (i.e., social acceptability, landings of main fish species, and their market value) with empirical results and the scientific literature using data from Portugal. [ABSTRACT FROM AUTHOR]

The cape petrel (Daption capense) is an abundant procellariform in seabird assemblages attending fishing vessels in the Southwestern Atlantic Ocean. The bulk of extant information comes from surveys conducted during the breeding season at Antarctic and sub-Antarctic sites; however, most of their ecological aspects during the non-breeding season remain largely unknown. We performed on-board census and stable isotope analysis in blood and feathers from 30 adult petrels during the non-breeding season in waters off Argentina. Cape petrels attending ice trawlers showed a higher abundance during winter compared to other seasons. The lack of correlation of isotopic values between tissues suggests changes in the diet and foraging locations between the moulting period and the non-breeding season. Isotopic mixing models revealed low-trophic-level sources as the main contributors to this petrel's diet while pelagic-demersal fish species targeted by fishing vessels showed the lower contribution. The discrepancies between methods could be a result of partial use of offal/discards or low use of these due to size/mechanic limitations. These findings reinforce the idea of zooplankton and small-pelagic fish facilitation during the hauling operatory and the relevance of combining different methods for a thorough understanding of prey-predator relationships. [ABSTRACT FROM AUTHOR]

Valorization of persimmon discards is a current challenge for the food industry. Obtaining dehydrated persimmon products can be a good option, but studies are necessary to predict consumer responses before placing new products on the market. In this study, we produced dried slices, chips, leathers and powder from persimmons that were discarded at harvest. A consumer study was performed with 100 participants. For a realistic context, the four products were presented to the participants in specifically designed packages to simulate commercial packages. The participants were asked about their interest in having each product available on the market. Then, they were asked to taste the samples and to state their acceptance and purchase intention. The participants characterized the main sensory properties of the samples using the CATA questions. The consumption contexts evoked by each product were also investigated based on the item-by-use method, plus the CATA questions. Our results revealed that, before tasting the samples, the participants showed special interest in having chips and slices available on the market. After tasting, the participants reported very good acceptance of chips, slices and powder, but leathers were less liked. According to the consumer characterizations, slices had the most intense persimmon taste and a succulent texture, while powder was characterized by its caramel taste. Chips were differentiated from the other samples, mainly for their crispy texture, while leathers were sticky and tasteless, which explained their poor acceptance. By evaluating the data on acceptance and the evoked consumption contexts together, we conclude that persimmon consumption could be enhanced by commercializing slices, chips and powder. The participants described chips and slices as healthy snacks in different daily situations, while powder could be used as a sweetener for yoghurts or hot drinks and as an ingredient for baking desserts. These are all contexts in which fresh persimmon would be not consumed as reported by the participants. [ABSTRACT FROM AUTHOR]

Fisheries extension programmes frequently fail to secure mandatory or voluntary adoption of bycatch reduction devices and techniques. Approaches for improving the outcomes of extension programmes are often based on ad hoc assessments and do not consider human behaviour or change theories. This paper offers an in-depth analysis of extension activities that led to various adoption outcomes in two prominent bycatch case studies in the United States: turtle excluder devices in shrimp trawl fisheries and dolphin bycatch in the tuna purse seine fishery. Using a grounded theory approach to text analysis of interviews and documents, I examine five periods of voluntary or mandatory adoption efforts. I explain the outcomes through the lens of diffusion of innovation theory. The most effective extension programme involved informative and persuasive efforts, enforced regulations, and commercially practical bycatch reduction devices. Voluntary adoption occurred under exceptional circumstances of public and political pressure and a device that offered substantial benefits to the adopter. The two periods of successful adoption applied the most core principles of diffusion theory. This paper concludes with recommendations for how change agents can apply diffusion theory to future fisheries extension programmes to improve the adoption of bycatch reduction devices. [ABSTRACT FROM AUTHOR]

The EU deploys technical measures (TMs) to avoid unwanted catches—here, overquota catches and juveniles of commercial species—including gear specifications and closures. In 2012, the European Commission had asked its advisory committee, Scientific, Technical, and Economic Committee for Fisheries (STECF), to evaluate the TMs and provide recommendations for improvement. In 2012–2013, STECF judged that the TMs had failed to achieve their objectives and identified approaches for improvement: (1) regionalization and move away from top-down management; (2) bottom-up results-based management to internalize the costs to the resource into individual businesses; and (3) abandon threshold percentages of bycatch leading to perverse incentives. In 2014, the new EU Common Fisheries Policy came in force, with a landing obligation (LO), and regionalization. In 2019, the new TM regulation (TMR) came in force. Besides sets of regional baseline measures, the TMR allows for regional proposals for amendments and results-based bottom-up approaches ("the good"). However, the LO is not enforced, therefore, not providing the incentive for change in fishing practices; and despite avoidance strategies being available regional, innovative bottom-up practices are still rare ("the bad"). TMs still contain threshold percentages ("the ugly"). The onus for bottom-up initiatives is on the industry, although new governance structures are needed to facilitate this. [ABSTRACT FROM AUTHOR]

Avoiding unwanted catches and reducing discards is an important objective of fisheries management. Fishers can avoid unwanted catches to some extent by improving selectivity of their fishing operations. This can be achieved through technical measures and gear modifications but also by adjusting when and where fishing takes place. Having access to real-time information, as provided through information sharing within a fleet, can help fishers avoid unwanted catches. Yet, there often remains a reluctance to share catch information with others. This paper compiles information from 15 case study examples of existing information sharing schemes in fisheries throughout the world. We compare the structure and operation of each of these schemes and determine what motivated participants to join and share potentially sensitive catch information. While there is no one-size-fits-all approach to designing and implementing information sharing schemes in fisheries, this paper highlights how industry and stakeholder support is often important, and understanding the needs, concerns, and motivations of any group of fishers is fundamental in developing and expanding such approaches. [ABSTRACT FROM AUTHOR]

Context: Contrary to other ocean basins, Indian Ocean catches have increased consistently since 1950, although reported data are known to be incomplete. Fish is a crucial food source in the Indian Ocean; however, ineffective management often empowers over-exploitation. Aims: We synthesised and reviewed Indian Ocean reconstructed catch and effort data by fishing sector and fishing country at the ocean-basin scale. Methods: We aggregated reported and reconstructed unreported catch and effort data for the Indian Ocean and derived catch-per-unit-effort (CPUE) time-series by sector. Key results: Indian Ocean rim country catches dominated in the Indian Ocean. Small-scale catches in the Indian Ocean have grown continuously by over 300% from 1.9 × 106 tonnes (Mg) year−1 in 1950 to 6.5 × 106 tonnes year−1 by 2018. By contrast, total industrial catches from the Indian Ocean have reached a plateau at ~8.5 × 106 tonnes year−1 since the late 1990s, after having steadily risen from very low levels in the early 1960s. Unreported catches declined from 45 to 25% of total catches. Total fishing effort, driven by the industrial sector, has increased 30-fold since 1950 from 0.4 × 109 to 11 × 109 kW-days by 2010, whereas CPUE has declined 78%, with steeper declines in the small-scale (>80% since 1950) than in the industrial sector (65% from its 1981 peak). Conclusions: The different sectoral patterns in the Indian Ocean compared with other ocean basins are likely to be due to the region's high dependence on small-scale fisheries and the later onset but swift growth of industrial fishing. The declining CPUE suggests strong decreases in stock biomass caused by strongly increasing fishing effort, especially in the industrial sector. Implications: Indian Ocean countries should prioritise lower-impact well-managed domestic small-scale fisheries to maximise long-term, sustainable nutrient supply for local livelihoods. Fisheries catches in the Indian Ocean have increased consistently since 1950, in contrast to declines observed in other oceans. Small-scale fisheries, accounting for 40% of catches, have grown consistently since 1950, whereas industrial fisheries have flatlined since the late 1990s, despite strongly growing fishing intensity. Indian Ocean countries dominate catches, whereas distant water fleets from other areas of the world account for a much small share. The combination of slowly growing catches despite strongly increasing fishing intensity suggests declining fish abundances, reinforcing sustainability concerns. [ABSTRACT FROM AUTHOR]

Comprehensive catch data are fundamental to support the sustainable management of large pelagic fisheries. However, catch data reported by the Indian Ocean Tuna Commission (IOTC) on behalf of its member countries currently under-represent the extent of these fisheries in the Indian Ocean. We reconstructed fisheries catches of large pelagic species for the Indian Ocean from 1950 to 2020, aiming to improve the comprehensiveness of existing reported data and to provide more ecologically relevant datasets for research and management uses. We reconstructed catches for 42 countries operating five major gear groups (longline, purse seine, gillnet, pole-and-line, and other gears) in the large pelagic fisheries. Reconstructed catches were 30% higher than the data reported by the IOTC. We demonstrated that distant-water fishing fleets historically dominated large-scale industrial fishing but were gradually replaced by fleets flagged to Indian Ocean rim countries. Our results also indicated an average discard rate of ~14% over the 1950-2020 period, primarily attributable to extensive discarding practices associated with longline and gillnet vessels. Reporting over time has improved only for tunas, whereas shark catches still remain under-reported, accounting for 51% of total unreported landings and discards in 2020. We confirmed substantial taxonomic aggregation in the data reported by the IOTC on behalf of its member countries, masking important patterns and trends and further complicating the sustainable management of exploited species in the Indian Ocean. We recommend substantially increased observer coverage and far better and stronger support by all member countries to improve the fisheries statistics in the IOTC.

Simple Summary: Artisanal fishing constitutes a subsistence activity in much of the world. Changes in fishing legislation can damage the sector if rapid adaptations are not achieved. As Europe demands landing of all catches, except those whose survival is scientifically proven, this study proposes possible improvements for the sector through a pilot study. We evaluated the survival of discarded fish and the possible recapture once they have reached a commercially profitable size. Europe calls for the end to fisheries discards, which means bringing all caught fish (subject to minimum sizes or quotas) to land. This decision is beneficial to the ecosystem, since it forces the selectivity of the fishing gears to improve. However, artisanal fishermen find themselves in a vulnerable situation where their subsistence depends on catches with small profit margins. An exemption to this landing obligation exists, as it is also ruled that those animals whose survival is scientifically guaranteed may be returned to the sea. Here we study the survival of Plectorhinchus mediterraneus captured by hookline and gillnet, as well as their physiological recovery. Survival exceeds 93% in both cases. The physiological assessment of primary (cortisol) and secondary (energy mobilization, acid-base and hydromineral balance, and immune system) stress responses indicates that surviving animals are able to recover after fishing. Thus, we propose the optimal size of capture of this species to achieve greater economic benefit. For this, we rely on the prices according to size in recent years, as well as on the growth curves of the species. In this way, by releasing fish of less than 1 kg, the current benefits could be multiplied between 2.3 and 9.6 times. This pilot study lays the groundwork for regulating artisanal fisheries through scientific data related to survival of discards along with information on the sale prices. [ABSTRACT FROM AUTHOR]

The market demand for marine-based cosmetics has shown a tremendous growth rate in the last decade. Marine resources represent a promising source of novel bioactive compounds for new cosmetic ingredient development. However, concern about sustainability also becomes an issue that should be considered in developing cosmetic ingredients. The fisheries industry (e.g., fishing, farming, and processing) generates large amounts of leftovers containing valuable substances, which are potent sources of cosmeceutical ingredients. Several bioactive substances could be extracted from the marine by-product that can be utilized as a potent ingredient to develop cosmetics products. Those bioactive substances (e.g., collagen from fish waste and chitin from crustacean waste) could be utilized as anti-photoaging, anti-wrinkle, skin barrier, and hair care products. From this perspective, this review aims to approach the potential active ingredients derived from marine by-products for cosmetics and discuss the possible activity of those active ingredients in promoting human beauty. In addition, this review also covers the prospect and challenge of using marine by-products toward the emerging concept of sustainable blue cosmetics. [ABSTRACT FROM AUTHOR]

Fisheries have important impacts on marine biodiversity. In this work, combined information on the abundance, species richness, diversity indices, species composition, trophic level and vulnerability index were examined for the first-time to detect differences in five units related to trawl fishing: the fish assemblage entering the trawl codend, and the escaping, retained, discarded and landed fractions, derived by the gear and fisher selection practices. The work was based on a case study conducted in the Mediterranean Sea, using three different meshes in the trawl codend (40mm-40D and 50mm-50D diamond meshes, and 40 mm-40S square meshes) and a cover of the codends with small mesh size. In general, trawl fishing produces an escaping fraction that was always lower in abundance, richness, and vulnerability index, similar in diversity indices and trophic level, and different in species composition compared to the fish assemblage entering the codend. In almost all cases, fishers selected as landings a fraction that was the lowest in diversity indices, and the highest in trophic level. In contrast, fishers discarded a fraction that was the highest in diversity and vulnerability index, and the lowest in trophic level. Although the three codends did not differ significantly in the fraction of escapees in terms of diversity indices, trophic level, and vulnerability index, the 40S codend showed a significantly higher percentage in the escaping number of species and individuals, and less differences in the species composition; in addition, lower percentage in abundance of discards and higher of landings in the retained catch (0.6:1) than did the other two codends (0.9:1). It was suggested that an urgent modification of the trawl for the elimination of the discarded highly vulnerable species (e.g. Elasmobranchs) is needed, and that trawl species-selectivity should be improved by allowing escape or avoiding catch of the discarded fraction to minimize biodiversity losses.

Deep-sea fisheries suffer from the very low studies and attentions in the Egyptian water of the Mediterranean Sea in spite of its importance in the other parts of the Sea for the fisheries economy and biodiversity. In this study, the pattern of deep-sea catch in the eastern part of the Egyptian Mediterranean coast, in terms of the catch per unit effort (CPUE), diversity, Sharks, and discards, was investigated using two commercial fishing vessels between 2017 and 2018 to support the unknown data on deep-sea habitats and put the Egyptian country on the map for current and future deep-sea exploring and management. The fishing operations were constructed at depths ranging from 350 to 800 m. The resulted data of the catch were separated into targets, bycatch, and discards based on a trip. Total annual catch was 17478.09 kg, both targets and by-catch accounting for 15903.09 kg and a percentage of 90.99 % (targets 69.92 %; bycatch 21.07 %), while the discards accounted 1575.00 kg (9.01 %). Seasonally, the highest total catch was during summer (6637.50 kg;37.97 %), while the lowest was in autumn (1962.29 kg; 11.23 %). CPUE/trip were as follows: target (19.81± 8.85 kg), bycatch (6.96±2.49 kg), and discards (5.51±2.78 kg). The diversity included four species of red shrimp (Aristaeo morpha foliacea, Aristeus antennatus, Plesionika edwardsii, and Parapenaeus longirostris) as the main targets in a percentage of 8.89 % together. The highest abundant was A. foliacea (48.73 %), it was measured from 8.5 to 23.5 cm (TL) and weighed from 8.1 to 58.6 g, with its majority in winter, followed by A. antennatus (14.99 %), with the majority in spring, while P. longirostris (2.65 %) was the least abundant. Bycatch comprised of 23 species, (8 cartilaginous;12 bony fishes; 3 cephalopods). The major fish species was M. merluccius (15.162 %), its highest season was autumn (16.804). Discards comprised of 18 species (5 cartilaginous species;11 bony fishes,1 Decapoda, and 1 starfish). This study has confirmed Heptranchias perlo and bony fish Lophius budegassa, while the squid Histioteuthis bonnellii, Decapoda Polycheles typhlop, Sea star Ceramaster grenadensis, were recorded here newly. The findings highlighted the significance of the insufficient data on deep-sea fisheries for commercial and biodiversity purposes, recommending the continuous updating, monitoring for further management.

The current European Union fisheries policy encourages improving handling practices to increase the survival of discards. Trawling on the Mediterranean upper slope often generates over 30% of discards of the total catch. Among other species, Nephrops norvegicus juveniles are abundantly returned to the sea, sometimes exceeding 40% of discarded biomass. N. norvegicus discard survival probability has been recently shown to be related to vitality on board and to vary seasonally, being especially low during the summer (0.06). Environmental characteristics (especially, high on-deck temperature in summer) make it necessary to improve vitality on board in order to increase discard survival. We therefore tested new discard handling methodologies for a Mediterranean mixed trawl fishery, with N. norvegicus as the target species. The results showed a survival rate on board higher than 0.8 resulting from vitality status improvements achieved by immersing N. norvegicus in cooled seawater on board during the catch selection and discard time. The implementation of this method would make an important contribution to more sustainable Mediterranean trawl fisheries.

The Landing Obligation (LO), introduced in 2015 by the Common Fisheries Policy of the European Union (EU-CFP), has been subject to a transitional period until recently. The rationale behind the measure is that all fish species subject to a total allowable catch (TAC) must be landed to increase the sustainability of fishing activities. Through the analysis of official statistical data, it is possible to find out which species of fish were landed and their relative importance, including their monetary value, and verify the potential for consumer acceptance. Some insights are drawn from the interconnection between these three factors (i.e., social acceptability, landings of main fish species, and their market value) with empirical results and the scientific literature using data from Portugal.

A detailed account of a variety of species foraging on Greenland halibut (Reinhardtius hippoglossoides (Walbaum, 1792)) fisheries discards associated with a commercial fishing vessel in central Baffin Bay, Nunavut, Canada is presented. Species observed included three marine mammals: northern bottlenose whales (Hyperoodon ampullatus (Forster, 1770)), sperm whales (Physeter macrocephalus Linnaeus, 1758), and a hooded seal (Cystophora cristata (Erxleben, 1777)), and two marine bird species: northern fulmars (Fulmarus glacialis (Linnaeus, 1761)) and glaucous gulls (Larus hyperboreus Gunnerus, 1767). Interspecies and intraspecies interactions were observed while species were in close proximity to the stern and starboard of a commercial fishing vessel confirming anecdotal reports from boat captains. Improved understanding of marine mammal and bird interactions with fisheries in the Arctic is required to accurately assess financial and ecological (i.e., bycatch) losses, potential for entanglement and to predict the likely impact on energy flow and transport of these resource subsidies throughout the Arctic marine ecosystem.

Thinking about design in post-human terms (Forlano, 2017) challenges designers to consider the effects of their designs on the more-than-human world, and in particular to consider non-human actors as users of our designs (Forlano 2017, Cruickshank & Trivedi 2017). However, the post-human turn also calls into question the modernist assumption that “good design” is predicated on notions of instrumental use, which underpins user-centred design, the dominant perspective in digital and interaction design. I propose an alternative, based on Willis’s ontological designing (Willis 2006) and Yuk Hui’s digital ontology (Hui 2016), which highlights the role of ongoing care and maintenance in the ontology of the digital, and argue that discards, and in particular digital discards, have a peculiar ontological status within this theory which offer promise for future study of digital design beyond instrumental use, and it’s entanglements with the more-than-human.

Valorization of persimmon discards is a current challenge for the food industry. Obtaining dehydrated persimmon products can be a good option, but studies are necessary to predict consumer responses before placing new products on the market. In this study, we produced dried slices, chips, leathers and powder from persimmons that were discarded at harvest. A consumer study was performed with 100 participants. For a realistic context, the four products were presented to the participants in specifically designed packages to simulate commercial packages. The participants were asked about their interest in having each product available on the market. Then, they were asked to taste the samples and to state their acceptance and purchase intention. The participants characterized the main sensory properties of the samples using the CATA questions. The consumption contexts evoked by each product were also investigated based on the item-by-use method, plus the CATA questions. Our results revealed that, before tasting the samples, the participants showed special interest in having chips and slices available on the market. After tasting, the participants reported very good acceptance of chips, slices and powder, but leathers were less liked. According to the consumer characterizations, slices had the most intense persimmon taste and a succulent texture, while powder was characterized by its caramel taste. Chips were differentiated from the other samples, mainly for their crispy texture, while leathers were sticky and tasteless, which explained their poor acceptance. By evaluating the data on acceptance and the evoked consumption contexts together, we conclude that persimmon consumption could be enhanced by commercializing slices, chips and powder. The participants described chips and slices as healthy snacks in different daily situations, while powder could be used as a sweetener for yoghurts or hot drinks and as an ingredient for baking desserts. These are all contexts in which fresh persimmon would be not consumed as reported by the participants.

Bottom trawling in the Mediterranean Sea has compromised the availability of demersal fishery resources, primarily due to decades of overexploitation beyond sustainability thresholds. Low selective bottom trawl nets have exacerbated this situation by catching large numbers of under-sized or immature individuals of targeted and not-targeted commercial species that are subsequently discarded. EU legislation requires EU Mediterranean countries to recover demersal fish stocks to sustainable levels by January 2025. This is a challenging requirement under current management scenarios that mainly focus on reducing fishing hours, compromising the activity of the fleets. While social networks among fishing fleets and fisherman associations are essential for facilitating the transition to sustainable exploitation, improving the selectivity of bottom trawl gears is proposed as a viable option beyond reducing fishing hours. This study presents the benefits of improving bottom trawlers net selectivity in multi-species NW Mediterranean coastal and deep-sea fisheries to reduce the catch of non-commercial sizes and discards. Data from selectivity experiments and literature review, fish market landings and a regional monitoring program in the FAO geographical sub-area 6 were used. Results indicate that in the short term, enhanced selectivity leads to an increase in the proportion of fish that are closer to their minimum conservation reference sizes or sizes at maturity, while minimising the impact on commercial catches. Sustainability may be achieved, though beyond 2025, with measures complementing selectivity. These include the adoption of semi-pelagic otter doors to mitigate the impact of trawlers on the seabed and the expansion of no-take marine reserves to ensure habitat recovery and spillover effects. [ABSTRACT FROM AUTHOR]

Small-scale fisheries (SSFs) in the Mediterranean and Black seas play a significant social and economic role, representing 84% of the fishing fleet (70,000 vessels), 26% of total revenue (USD 633 million) and 60% of total employment (150,000 people), with the Food and Agriculture Organization (FAO) recently taking important initiatives to sustain livelihoods. Effective management of important natural fisheries resources that sustain livelihoods requires a holistic approach accounting for all parts of the catch. Quantitative data on seasonal catch dynamics together with classification of bycatch species to IUCN vulnerability status and associated revenues from retained incidental catch were used to reveal the effect of a small-scale shrimp trap fishery on bycatch. We use three main quantitative variables (i.e., density, biomass and number of bycatch species) and show a positive correlation between bycatch and the seasonal catch dynamics of the target species during late spring and summer. On the contrary, discards were proportionally lower during winter, with the majority of discarded fish species not considered endangered. Six retained species in spring–summer and five discarded species in winter were found to modulate the structure of species' assemblage. Out of 55 bycatch species, 26 were retained and 29 discarded. Only four species were considered threatened, all of which were caught in very low numbers (<2 individuals), while the majority of the retained species was not considered endangered. The rapid sorting time (<1 min/per trap) pointed towards a decreased effect on certain discarded crustacean species and a significant reduction in total bycatch with timely haul time (from 71 to 47%). The results of this study can be used when considering future mitigation measures for this fishery, while the methodology used can provide insights into the management of similar trap fisheries worldwide when taking into account the sustainability of SSFs and the regional vulnerability status of bycatch species. [ABSTRACT FROM AUTHOR]

Bottom trawling is a common fishing method that targets bottom-dwelling fisheries resources. It is non-selective and large amounts of by-catch are discarded, raising serious sustainability and ecosystem conservation concerns. In this study, a shallow-water bottom-trawl fishery was evaluated using logbook catch data between 2011 and 2019 and the species composition data collected by fisheries observers between 2016 and 2019. The logbook data showed a twenty-fold increase in the annual catches with a ten-fold increase in fishing effort and an increase in the proportion of retained catch from 2011 to 2019. The observer data showed that for prawn, the by-catch ratio ranged from 1:3 to 1:9 during the four years. Multivariate analysis revealed significant differences between the compositions of retained and discarded catches mainly attributed to Pellona ditchela, Nematopalaemontenuipes, and Secutor insidiator. There was no significant decline in species diversity and the trophic level of the catches over the 4-year observer period indicating no marked impact of trawling on the stock at the current level of fishing effort. This study provides baseline information on the prawn trawl fishery against which the performance of the management regulations may be evaluated towards the Ecosystem Approach to Fisheries management. [ABSTRACT FROM AUTHOR]

This study characterized the fishery dynamics of blue whiting, a bycatch species of the bottom trawl Norway lobster fishery, in the NW Mediterranean. Landings and effort data over the last two decades were combined with current information on the spatial distribution of effort and catch, and with the size and age structure of blue whiting over the year. Recruitment to the demersal habitat occurred from 5 cm total length (TL) over the shelf break in spring (April-May), when discards showed the highest values (>95% of the catch). Adults were located over the upper slope, and large individuals (≥26 cm TL) were abundant during the reproductive period (January-March). A decline in landings has been observed in the last decade, probably related to the absence of intense deep convection processes in winter since 2013, which favour recruitment of the species. The effect of exploitation on the decrease in landings cannot be disregarded considering that the bulk of the catch is made up of immature (age 0) individuals, and the presence of old individuals is very low.

This study evaluates the impacts of mesh size of the net, fishing depth and season on the catches of target, non-target and discarded species for short mackerel Rastrelliger brachysoma gillnet fishery in the vicinity of Pattani Bay, Gulf of Thailand. The catches were examined for species composition, catch efficiency and size of catch. Samples were obtained monthly from February 2019 to February 2020 at three fishing depths (2.0, 4.0 and 6.0 m) using gillnets with three different mesh sizes (3.0, 4.0 and 4.5 cm). Including the target species, 112 species were collected, the majority of which were non-targeted fishes and crustaceans. The target species, Rastrelliger brachysoma, contributed only 6.0% by number and 8.76% by weight to the total catches. The 111 non-target species were classified into five categories based on potential sale prices. A total of 18 species, equivalent to 3.04% by weight of the total catches, were considered to be of negligible value and discarded or sold for the production of fish meal. Temporal variability was observed for number of individuals and biomass of total catches; the compositions of the catches clustered to two distinct seasons from December to March and from April to November, respectively. Spatial variability in this study focused on the depth profile which was found to significantly influence species richness and sizes of some fish species. For 12 species, mesh sizes of the gillnets significantly affected the number of individuals caught, as well as their weight and sizes. The novel findings of this study provide essential information that can be used for the sustainable management of the Rastrelliger brachysoma fishery in the Gulf of Thailand. [ABSTRACT FROM AUTHOR]