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Fisheries discards in the Moroccan Mediterranean Sea present a significant challenge at the intersection of marine resource management and societal concerns. Bottom trawl fisheries, which involve dragging nets along the seabed, capture a wide array of marine species, many of which are subsequently discarded. This study offers the first comprehensive analysis of discard composition from Moroccan trawl fleets, drawing on data collected from 2019 to 2022 through an onboard sampling program. Among the 103 species from 59 families discarded, 16 were elasmobranchs and 88 were bony fishes. Discarded biomass showed significant variation based on season, fishing areas, and their interaction, with discard ratios ranging from 1.06% to 43.7%. Teleostei made up the predominant fraction of discarded biomass, followed by Elasmobranchii, Thaliacea, and Holocephali. The study found significant variations in mean biomass values across different ports and seasons, highlighting dynamic patterns in biomass distribution among marine classes. However, the number of species recorded in discards remained stable across ports and seasons, indicating consistent environmental conditions. The findings underscore the need for targeted fishery management measures to minimize the ecological impacts of discards, tailored to specific times and locations. [ABSTRACT FROM AUTHOR]

This study analyses a highly damaging and prevalent fishing practice of trawl infringements, which is one of the crucial components of IUU fishing in Turkish waters. The raw data gathered from the Turkish Coast Guard Command (TURCG), covered 2012 – 2014 period. Data covered a total of 1040 trawl infringements, with considerable differences in trawling violations among the seas surrounding Türkiye; the Black Sea, the Sea of Marmara, the Aegean Sea, and the Mediterranean Sea. With respect to trawling infringements, the Sea of Marmara (37%) and Istanbul Strait (15%) were the hot points. The most common infringement type was trawling in a closed area (43%) and when combined with the rate of infringements on trawling during the closed season (10%), these violations accounted for 53% of spatio-temporal infringements. Regarding illegal trawling by vessel type, trawl vessels had a 44% share and non-trawlers had a share of 56%, of which included infringements by other type of fishing vessels (46%) and non-fishing vessels (10%). It was also found that infringement by vessels smaller than 12 meters in length had a share of 46%. These vessels (known as "şebeke" in Turkish), trawl illegally using small types of nets and gears in coastal waters without giving any obvious indication of fishing activity. The results of this study will be useful to policy-makers, practitioners and scientists to successfully combat trawling infringements by providing information on distribution, intensity and methods of trawl violations.

In many fisheries, such as trawl fisheries, sharks appear among the catches as bycatch or discards, and these species include velvet belly (Etmopterus spinax) and blackmouth catshark (Galeus melastomus). The objective of this study was to research the feeding habits of both species in the Gulf of Cádiz and to identify possible differences in diet depending on size and time of day. The most frequent sizes were 12–16 cm for E. spinax and 14–20 cm for G. melastomus. Both species preyed mainly on euphausiaceans and teleosts; their Index of Relative Importance (IRI) per species were as follows: E. spinax 42.30% IRI, 21.66% IRI; G. melastomus 52.33% IRI, 27.26% IRI, respectively. Only Etmopterus spinax showed significant variation in diet as a function of the time of day (p < 0.05), although both species showed similar patterns of feeding throughout the day. With respect to size, E. spinax consumes more cephalopods and teleosts as its size increases, while G. melastomus increases its consumption of decapods. [ABSTRACT FROM AUTHOR]

In this study, we aimed to examine the status and historical change of trawl fishing fleet in the Foça in the Aegean Sea. The data of the study representing all actively working trawlers in 1998-1999 and 2019 were collected through face-to-face interviews with trawler boat owners in Foca. The questionnaire consisted of questions related to the characteristics of the vessels, fishing activity, socio-demographics of fishers, running costs, annual landings of species and management issues. The study indicated that the annual landings of the main target species significantly decreased over the last two decades. Fishers reported the landings of some species including Dentex gibbosus, Dentex macrophthalmus, Homarus gammarus, Mustelus mustelus, Octopus vulgaris, Parapenaus longirostris, Scomber colias, Scorpaena porcus, Scorpaena scrofa, Spicara smaris, Trachurus spp. and Zeus faber decreased considerably over this period. Over the same period, a decrease was found in the mean length of Merluccius merluccius, Lophius piscatorius and Zeus faber. The vessels’ fuel tank volume and tow duration showed significant increases from 1999 to 2019. The trawl fleet decreased by ~75% from 1999 to 2019 and 55% of the current fishers reported that they may leave the fishery sector within the next 10 years. A change was also determined in the tradition of the sharing system, which is the number of crews paid in shares rather than a fixed salary, significantly decreased. Moreover, the crew numbers from vessel owners’ households significantly decreased. As a result, we discussed the changes, problems, regulations and restrictions related to trawl fishery in Foça, which used to be the most important trawling fishing center of the Aegean twenty years ago. We found dramatic changes in many aspects compared to what it was two decades ago and provided suggestions regarding fisheries management.

Abstract Marine biodiversity stewardship requires costly and time‐consuming capture‐based monitoring techniques, which limit our understanding of the distribution and status of marine populations. Here, we reconstruct catch and demersal community composition in a set of 24 fishing sites in the central Tyrrhenian Sea by gathering environmental DNA (eDNA) aboard commercial bottom‐trawl fishing vessels. We collected genetic material from two sources: the water draining from the net after the end of hauling operations (“slush”), and custom‐made rolls of gauze tied to a hollow perforated sphere placed inside the fishing net (“metaprobe”). Species inventories were generated using a combination of fish‐specific (Tele02 12S) and universal metazoan (COI) molecular markers. DNA metabarcoding data recovered over 90% of the caught taxa and accurately reconstructed the overall structure of the assemblages of the examined sites, reflecting expected differences linked to major drivers of community structure in Mediterranean demersal ecosystems, such as depth, distance from the coast, and fishing effort. eDNA also returned a “biodiversity bonus” mostly consisting of pelagic species not catchable by bottom trawl but present in the surrounding environment. Overall, the “metaprobe” gauzes showed a greater biodiversity detection power as compared to “slush” water, both qualitatively and quantitatively, strengthening the idea that these low‐cost sampling devices can play a major role in upscaling the gathering of data on both catch composition and the broader ecological characteristics of marine communities sustaining trawling activities. This approach has the potential to drastically expand the reach of ecological monitoring, whereby fishing vessels operating across the oceans may serve as opportunistic scientific platforms to increase the strength and granularity of marine biodiversity data.

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Trawling is one of the most common fishing methods used by small vessels. This method requires the vessel to operate at a constant low speed because the depth of the trawl must be kept constant. In addition, the operation is often conducted by a small number of people, who must simultaneously maneuver the vessel and fish, making automation desirable. To develop this device, a mathematical model of the vessel was created based on data collected from actual operation of the vessel, and simulations were conducted to determine what type of control system would be suitable. As a result, it was possible to grasp effective control methods, effects of disturbances such as tides and waves, and how to deal with effective parts to improve response.

Simple Summary: Fisheries are amongst the most important anthropogenic activities that strongly impact the marine environment. Therefore, stock assessments are routinely carried out to evaluate the status of the main commercial species to avoid overexploitation. However, these assessments do not take into account the possible mortality of fish due to interaction with fishing gear, and the evaluation of escape survival rates is needed. For the first time in the Central Mediterranean, this study evaluated the escape survival of the red mullet escaping from a bottom trawl. The survival rate of the control individuals (open codend) was higher compared to the treatment individuals (closed codend). Larger fish in the treatment group had a higher probability of dying, while the opposite was observed in the controls. In addition, treatment fish had significantly more wounds per fish than control fish, and were mainly injured around the head. The results highlighted that the sampling methodology was effective in collecting fish samples without affecting their survival rates. Although promising, these results need to be confirmed by further investigation before applying the survival rates in stock assessment models. Stock assessments routinely evaluate the status of commercially harvested species, but seldom account for the possible mortality of released or escaping fish. This study presents a method for estimating the escape survival of the red mullet (Mullus barbatus) from demersal trawling in the Central Mediterranean Sea. Fish escaping from the trawl codend were collected in a detachable cage, which was lined to reduce water flow and protect the sampled fish from further fatigue and injury. Control fish (from an open codend) showed high survival, 94% (87–97%, 95% Confidence Interval), and minimal injuries, while fish escaping through codend meshes had significantly increased injuries and reduced survival, 63% (55–70%). During 7 days of captive monitoring, treatment group mortality was highest in the first 24 h and ceased for both groups within 48 h. Conflicting length-related mortality was observed, where larger treatment fish had a higher probability of dying, while the opposite was observed in the controls. Analysis showed that treatment fish were significantly more injured than control fish, with treatment fish predominantly injured in the head zone. In conclusion, this improved methodology should be repeated to provide accurate escape mortality estimates for the improved stock assessment of the red mullet in the Central Mediterranean. [ABSTRACT FROM AUTHOR]

Identification of marine fishes across their geographical distribution is based primarily on morphological features. The ability of marine fishes to adapt to environmental changes sometimes leads to morphological differences that might give rise to wrong or misidentification of the fishes, unlike genetically based identification. Fish samples were collected with a trawl net used by demersal trawlers in Nigerian coastal waters between N 4.19823⁰ E 8.29929⁰ and N 6.18855⁰ E 3.14797⁰. The average length of the COI nucleotide sequences was approximately 584 bp. A total of 30 CO1 sequences were obtained from 18 fish species within 12 families with 97–100% identity with comparison to the Genbank database and BOLD. The average divergence within a species is 4.47%, 6.10% within a genus, and 15.94% within a family, while the maximum within a species and genus is 17.54% and 19.20% within a family. Four (4) species in the Nigerian marine environment have not been sequenced before in this study: Caranx fischeri, Pseudotolithus senegallus, Lagocephalus guentheri, and Sphyraena ensis. These findings will contribute to the barcode database of global marine fish species identification, provide baseline data for marine fishes in Nigerian waters based on the CO1 region, and serve educational purposes in universities, research institutes, fishery managers, and fish stock assessment.

From 1 June 2010 in the Italian coastal waters of the Northern Adriatic Sea, trawl fishery within three nautical miles became banned. This activity was previously allowed for some species as an exception to legislation. In order to evaluate the consequences both on demersal resources and economic yields of the trawl which will oblige fishermen to trawl beyond three miles, a pilot study was performed. Twenty hauls comparing catch discard and income between hauls within and external to three nautical miles were performed. Results highlighted differences in catch composition both for landing and discard. Landing per unit of effort and discard per unit of effort did not differ in relation to distance from the coast, while income was higher for offshore hauls than inshore ones even if not significantly. Fishery management is a complex task, and the results of this study can contribute to the debate providing new insights into the consequences of the regulation on the trawling within three nautical miles. Considering the high amounts of discard, the habitat damages caused by otter trawling, the presence of juveniles in coastal waters and data regarding fishermen income, this study supports the actual European Community regulation on coastal trawling. [ABSTRACT FROM AUTHOR]

Trawling is one of the most common fishing methods used by small vessels. This method requires the vessel to operate at a constant low speed because the depth of the trawl must be kept constant. In addition, the operation is often conducted by a small number of people, who must simultaneously maneuver the vessel and fish, making automation desirable. To develop this device, a mathematical model of the vessel was created based on data collected from actual operation of the vessel, and simulations were conducted to determine what type of control system would be suitable. As a result, it was possible to grasp effective control methods, effects of disturbances such as tides and waves, and how to deal with effective parts to improve response. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agriculture & Nature / Kahramanmaraş Sütçü İmam Üniversitesi Tarım & Doğa Dergisi is the property of Kahramanmaras Sutcu Imam Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Stock assessments routinely evaluate the status of commercially harvested species, but seldom account for the possible mortality of released or escaping fish. This study presents a method for estimating the escape survival of the red mullet (Mullus barbatus) from demersal trawling in the Central Mediterranean Sea. Fish escaping from the trawl codend were collected in a detachable cage, which was lined to reduce water flow and protect the sampled fish from further fatigue and injury. Control fish (from an open codend) showed high survival, 94% (87–97%, 95% Confidence Interval), and minimal injuries, while fish escaping through codend meshes had significantly increased injuries and reduced survival, 63% (55–70%). During 7 days of captive monitoring, treatment group mortality was highest in the first 24 h and ceased for both groups within 48 h. Conflicting length-related mortality was observed, where larger treatment fish had a higher probability of dying, while the opposite was observed in the controls. Analysis showed that treatment fish were significantly more injured than control fish, with treatment fish predominantly injured in the head zone. In conclusion, this improved methodology should be repeated to provide accurate escape mortality estimates for the improved stock assessment of the red mullet in the Central Mediterranean.

Reduction of discards from the Basque mixed bottom trawl fishery is a challenge. To improve the selective properties of the gear used by the fleet and supplement codend size selection, a square mesh panel (SMP) installed in the upper panel of the trawl was introduced in 2006. However, recent studies have shown that the release efficiency of this SMP is low due to lack of contact between the fish and the SMP. In this study, we tested the release efficiency of the SMP for four different gear configurations. We tested the effect of adding LED lights at two different positions and altering panel size and panel position in the trawl. The analyses were focused on two species: hake (Merluccius merluccius) and blue whiting (Micromesistius poutassou). The results showed that the position of LED lights did not significantly affect the SMP’s release efficiency for any species. However, increasing panel size had a significant positive effect on the release efficiency of blue whiting, and placing the SMP in the lower panel improved the release efficiency of hake. These results highlight the challenge of simultaneously improving the selective properties of gear for species with different behaviour, especially in mixed demersal fisheries.

Background. Atlantic horse mackerel, Trachurus trachurus (Linnaeus, 1758), is among bento-pelagic species subject to discard within deep-water rose shrimp fisheries, and how such species would react to light wavelength is therefore important, to be consistent with the Common Fishery Policy (CFP). Despite the existing literature currently available, there is still paucity of relevant information about how artificial light wavelengths affects the behaviour of T. trachurus juveniles. In this context, the effects of different artificial light wavelengths on some behavioural features of juvenile T. trachurus were investigated. Materials and methods. Maintained in a fish tank, the juveniles of Atlantic horse mackerel, after acclimatization, were subject to six different light wavelengths, representing the following colours: white, violet, blue, green, yellow, and red. Subsequently, behavioural features, specifically phototaxis (degree of attraction or repulsion toward the light source) were tested. Results. By phototaxis per light wavelength, the studied juvenile individuals produced statistical differences in the presence frequency (P < 0.05) revealed by blue that noticeably attracted some, relative to the white light that repulsed others. Yet, violet and red lights produced much less but no significant attraction of these juveniles (P > 0.05). Conclusion. The presently reported study has provided additional information about ecological knowledge and understanding specific to juvenile T. trachurus individuals, which can further the development of (selective) light fishing techniques, aimed at reducing unwanted catches of commercial pelagic fisheries.

Under the individual vessel quota regulations, the expected economic return of a multi species fishery is influenced by an array of a multi-component choice such as targeted species, landings per haul, harvesting time and its location. The components of effort allocation decisions are further complicated by changes in the market conditions and the constant movements of fish between spawning and feeding habitats. Migratory behavior influences the dispersal of species, relative availability of fish and its composition, and the bycatch likelihood across different locations over the course of a fishing year. The objective of this article is to investigate the optimal allocation of fishing effort in the Norwegian bottom-trawl fleet within economically important species; cod, saithe, and haddock across three heavily trawled areas—including southern and northern parts of the west coast of Norway, and the high sea areas of the Arctic—to achieve maximum expected economic return, with respect to the individual vessel quota constraints and bycatch considerations. The results from a mixed integer non-linear optimization problem evidence that the spawning migration of Northeast Arctic cod along the northwest coast, effort allocation behavior of coastal fleet, together with institutional regulations necessitate the substitution of fishing effort across different fishing locations within the fishing season to maximize expected return. The results of our study further reveal that the Arctic region to target cod is the biggest contributor to annual fishing revenue. By contrast, conducting saithe fishery in the southwest of the Norwegian coast has the lowest economic contribution. The results from Monte Carlo simulation demonstrate that the proposed model is effective and applicable for effort allocation decision analysis.

From 1 June 2010 in the Italian coastal waters of the Northern Adriatic Sea, trawl fishery within three nautical miles became banned. This activity was previously allowed for some species as an exception to legislation. In order to evaluate the consequences both on demersal resources and economic yields of the trawl which will oblige fishermen to trawl beyond three miles, a pilot study was performed. Twenty hauls comparing catch discard and income between hauls within and external to three nautical miles were performed. Results highlighted differences in catch composition both for landing and discard. Landing per unit of effort and discard per unit of effort did not differ in relation to distance from the coast, while income was higher for offshore hauls than inshore ones even if not significantly. Fishery management is a complex task, and the results of this study can contribute to the debate providing new insights into the consequences of the regulation on the trawling within three nautical miles. Considering the high amounts of discard, the habitat damages caused by otter trawling, the presence of juveniles in coastal waters and data regarding fishermen income, this study supports the actual European Community regulation on coastal trawling.

Seabirds interaction with trawl fishing gear was observed aboard the large freezing-processing trawler «Moskovskaya Olimpiada» during the pollock fishery in the Okhotsk Sea in January-April, 2015. In total, 579 observation rounds were realized including 105 ones during the trawl setting, 116 ones during hauling, and 358 ones during trawling, with total duration of 280.7 hours. In the observations, 1443 contacts of birds with the fishing gear were recorded. Light contact of a flying gull with the trawl net was observed in one case only; all other contacts were collisions with the wires. The warps and the depth sounder cable were the greatest hazard for birds. Collisions with the sounder cable during the trawling were the most frequent, with approximately 5 times higher frequency than with the same cable during the trawl setting or hauling. Almost all strikes with the wires were registered for northern fulmars (97.5 %) and the rest of the strikes — for large gulls. Gulls had only light contacts with the depth sounder cable (2 contacts afloat and 34 contacts in flight). Fulmars had contacts both with the depth sounder cable and warps. Flying birds of this species contacted with the depth sounder cable more frequently (75.5 %) than those sitting on the water. On the contrary, majority of fulmars (61.6 %) contacted with the warps being afloat in the process of their feeding. Several cases only (0.6 %) of direct interactions with the fishing gear caused the bird’s death. All these cases occurred with the fulmars drowned when they fell under the depth sounder cable (7 ind.) or under the warp (1 ind.). Frequency of the bird collisions with the wires differed prominently by the fishery districts, with the maximum in the Kamchatka-Kuril subzone (8.35 contacts/hour for fulmars and 0.22 contacts/hour for gulls). These spatial differences are related to the birds abundance near the ship that depends on distribution patterns of certain bird species in the Okhotsk Sea in winter. General frequency of the contacts depends credibly on intensity of the waste discharges after fish processing and on wind direction relative to the ship course.

There is currently very little information on the survival of discards of unwanted and unregulated catches of invertebrates after the stresses caused by capture. A great number of the unregulated invertebrate species form the basis of essential fish habitats for important fisheries resources such as hake, red mullet and cuttlefish. Thus, data on their survival after discarding may help to interpret the role of these species within the benthic ecosystems. Furthermore, descriptor 6 of the Marine Strategy Framework Directive (EU Directive 2008/56/E) foresees maintaining sea floor integrity at a level that ensures that the structure and functions of the ecosystems are safeguarded, and Article 7(d) of the Common Fisheries Policy (EU Reg. 1380/2013) foresees the implementation of management measures for fishing with low impact on the marine ecosystem and fishery resources. Survival measurements by direct recovery of tagged discarded species are not effective in bottom trawl fisheries, for which alternative studies such as semi-quantitative measures obtained on board prior to discarding can be considered as appropriate for mortality estimation. The present work assessed the survival of unwanted species using a semi-quantitative assessment on the deck of trawlers and at the laboratory for a period of 96 hours in two Mediterranean areas (the Catalan coast and the Ligurian and Northern Tyrrhenian seas). A high number of discarded invertebrates showed a high percentage of survival (>70%) in both assessments. The results can be used to provide information that can help to achieve higher survival levels of discarded specimens and enhance the productivity of fishing grounds by increasing the health of benthic ecosystems.

With the full implementation of the landing obligation on 1 January 2019, In European waters it will become mandatory for the trawling fleet to land at port all catches of certain species because, according to Article 15 of the new European Common Fisheries Policy, the species subject to the minimum conservation reference size (MCRS) cannot be discarded. Additionally, since 2005, trawlers over 15 m in length are required to carry an onboard vessel monitoring system (VMS), which generates information on fleet dynamics. The objective of this work was to provide a tool for avoiding unwanted catches by integrating the catch study of trawlers operating in the port of Blanes together with VMS data. To achieve this objective, the catches of 40 hauls were monitored, sampled and analysed together with VMS data for the years 2012-2014 integrated in a geographical information system. The results show that specimens below the MCRS were often captured in crinoid aggregation habitats, bottoms with maërl and muddy bottoms that were identified as nursery habitats of commercial species, e.g. Merluccius merluccius, Pagellus spp. and Mullus spp. VMS data showed considerable fishing pressure on areas with maërl and muddy habitats during the recruitment periods of these and other commercially relevant species. Implementing spatial or seasonal closures in habitats where species regulated by the MCRS are subject to catches could be a useful tool for preventing unwanted catches.

At least 12 seabird species aggregated permanently around the vessels of pollock trawl fishery in the Okhotsk Sea in January-April, 2015. They were attracted by the fish processing waste and small-sized fish falling from trawls. Fulmars dominated in all fishery districts except the East-Sakhalin subzone (their number was 68.9 % of all birds, on average), they were the most abundant at southwestern Kamchatka. The secondary abundant group of species was large-sized white-headed gulls of Larus genus (31.0 %), mostly slaty-backed gull. Species composition of aggregations and number of the birds were quite dynamic in space and time, but the largest and the most diverse aggregations were observed in the Kamchatka-Kuril fishery district where many seabirds wintered in the Pacific waters. The largest aggregation in this subzone had up to 23,000 ind. around one separate vessel, so hundreds of thousands birds may gather in the area of a trawling fleet operation. Size and species composition of the near-vessel aggregations are determined by biotopic preferences of the species and weather conditions. The pollock trawl fishery is regarded as a powerful factor of the seabirds habitat in the Okhotsk Sea, and the catching and processing waste is a reliable food base for huge bird community, particularly important in winter season.

Copyright of Journal of Taiwan Fisheries Research is the property of Fisheries Research Institute, Council of Agriculture, Executive Yuan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background. Atlantic horse mackerel, Trachurus trachurus (Linnaeus, 1758), is among bento-pelagic species subject to discard within deep-water rose shrimp fisheries, and how such species would react to light wavelength is therefore important, to be consistent with the Common Fishery Policy (CFP). Despite the existing literature currently available, there is still paucity of relevant information about how artificial light wavelengths affects the behaviour of T. trachurus juveniles. In this context, the effects of different artificial light wavelengths on some behavioural features of juvenile T. trachurus were investigated. Materials and methods. Maintained in a fish tank, the juveniles of Atlantic horse mackerel, after acclimatization, were subject to six different light wavelengths, representing the following colours: white, violet, blue, green, yellow, and red. Subsequently, behavioural features, specifically phototaxis (degree of attraction or repulsion toward the light source) were tested. Results. By phototaxis per light wavelength, the studied juvenile individuals produced statistical differences in the presence frequency (P < 0.05) revealed by blue that noticeably attracted some, relative to the white light that repulsed others. Yet, violet and red lights produced much less but no significant attraction of these juveniles (P > 0.05). Conclusion. The presently reported study has provided additional information about ecological knowledge and understanding specific to juvenile T. trachurus individuals, which can further the development of (selective) light fishing techniques, aimed at reducing unwanted catches of commercial pelagic fisheries. [ABSTRACT FROM AUTHOR]

Trawling operations, extended wide and far, have resulted in the emergence of many non-conventional fishery resources. Apart from regular commercial crustacean resources of shrimps, crabs and lobsters, crucifix crab, C. feriatus, C. smithii and C lucifera are forming bulk catch in regular trawl fishery recently. The south-west coast of India contributes onethird of country’s stomatopod production in which Oratosquilla nepa contributes the maximum. Extension of fishing grounds has resulted in exploitation of larger-sized stomatopods Harpiosquilla harpax, which is edible. Present study aims at understanding the spatio-temporal distribution of these non-conventional resources, through GIS-based resource mapping which is indicative of their distribution and abundance. The study showed that there is good potential for commercial exploitation of non-conventional resources which can form a part of the commercial fishery in coming years to enrich the seafood availability and to provide new avenues for fishermen for maximising their returns from the fishery. [ABSTRACT FROM AUTHOR]

Highlights • There are different demand and supply side reasons for discarding bycatch. • Past research has mainly focussed on finding technical solutions in the catch sector. • Solutions need to be developed in the market and consumer end of the seafood supply chain. • Case study shows that longer-term fresh fish supply may otherwise be compromised. Abstract Discarding is a worldwide problem in small-scale and industrial fisheries alike. A significant proportion of discarded fish are edible, and if high post-release mortality occurs, the practice may seem wasteful in the context of food security. There are different reasons for discarding which can be related to demand-side issues (e.g. market preferences), supply-side issues (e.g. on-board storage capacity), and management regulations (e.g. size limits). We carried out analyses to determine why discarding was occurring in a trawl fishery operating in southern Australia's Great Australian Bight. Currently up to 56% of the fishery catch may be discarded – of which a considerable portion are edible species. The economic viability of the fishery was also considered by revenue from both target species and bycatch species based on a typical vessel. Our research found there are no supply-side barriers and that discarding in this fishery is driven by demand-side barriers. Without addressing demand-side issues for discards, our economic analysis shows that this fishery may be economically challenged and in the broader context, this issue may compromise the long-term supply of fresh Australian fish. Much of the focus to deal with fisheries discards has been directed at the catch sector through development of technical modifications of the fishing gear. However, to help address the discard issue it is important that all supply chain participants, including consumers, understand and contribute to solutions. Our results suggest that if more emphasis was placed on the market and consumer end of the seafood supply chain, the discard problem could be better addressed. We suggest a range of initiatives from government, industry, NGOs and seafood consumers. Technical and industry-led approaches such as sustainability through programs and certification requiring fisheries to meet standards is only part of the story. Consumer awareness regarding their role in creating sustainable fisheries and sustaining locally important fisheries can be enhanced by selecting a wider choice of seafood for consumption. [ABSTRACT FROM AUTHOR]

The behavior of the Argentine shortfin squid (Illex argentinus) in reaction to a trawl net is reported from images obtained during one fishing tow operated by a commercial trawler in May 2015 in slope grounds off southern Brazil (depth 370-361 m; 33°37'S, 50°49'W). Video analysis utilized criteria to classify the horizontal and vertical distribution of squid in the field of view of the camera, posture (pitch and yaw), squid color patterns, escape reaction, swimming time and use of the tail fin. The monitored bottom trawl operation intercepted dense and patchily distributed schools of I. argentinus that could be observed for brief periods of time swimming ahead of the mouth of the trawl. Individuals were evenly distributed in the water column but concentrated on the center and right sectors of the trawl mouth. Most squids in the path of a trawl tended to swim by jet-propulsion for 10-20 s, tail-first and with regularly spaced fin flaps. Estimated speed (1.24 m s-1) was higher than cruise speed recorded for other ommastrephid squids in nature (0.3 m s-1), possibly reflecting an emergency escape reaction. After a period of sustained swimming ahead of the trawl, squid reacted in different ways including: a) slowing down and swimming into the net tunnel, b) shifting directions to escape through the trawl mouth sides, and c) swimming up, trying to escape over the top trawl panel, sometimes turning around pointing the tail towards the trawl mouth. [ABSTRACT FROM AUTHOR]

Abstract: The observations conducted during the Walleye Pollock expedition to the Sea of Okhotsk in January-April 2015 showed that various seabird species (at least 12) aggregate permanently around trawlers in the Sea of Okhotsk. The birds are attracted by fish-processing waste. The quantitative and species composition of aggregations is dynamic. The richest of these in terms of number of species and the most abundant (up to 23 000 individuals around one vessel at a time) are formed in the Kamchatka-Kuril subzone, where numerous overwintering birds arrive from adjacent ocean waters. The Northern Fulmar accounts for a major part of the aggregation (68.9% of all birds); this bird dominates most of the fishery areas. The second most-abundant group of species is large white-headed gulls of the genus Larus (31.0%), mainly the Slaty-backed Gull. In general, the pollock trawl fishery is regarded as an influential factor that causes large overwintering grounds of seabirds to form in the Sea of Okhotsk. Fish-processing waste disposed overboard supports a huge bird community by providing a stable food supply during the harsh season. [ABSTRACT FROM AUTHOR]

New techniques of fish tranport from fishing gears aboard is proposed for a case of mixed aggregations of chub mackerel and japanese sardine. These species resume their mass migration to the Russian waters since 2014. Submersible impeller pumps with hydraulic power drive are used usually for catch transport aboard in the world practice of purse seining of mackerel. However, this technique is unsuitable for mixed aggregations of mackerel and sardine because the impeller pump could damage the sardine. Applicability of the vacuum and waterjet pumps for this case is considered. The vacuum fish pump TransVac was designed in 1982, initially for transfer of damage-sensitive fish from fishing vessel to shore fish processing plant, and the waterjet fish pump SilkStream was designed in 1988 for transfer of alive fish and later was adapted for fish transport aboard from trawl and seine nets. Both types of fish pumps are recommended for the medium- and large-capacity fishing vessels working with the mixed aggregations of sardine and mackerel. Using of these pumps together with freezing equipment allows to avoid losses in quality of catch.

In this work we analysed the spatio-temporal variability of discards in the fishery of the deep-sea red shrimp Aristeus antennatus in the northwestern Mediterranean Sea. We sampled fishery discards in the fishing grounds of Palamós (the main harbour for this fishery on the Catalan margin), which are located in several areas of a submarine canyon. We found that the discard ratio in this fishery showed a marked seasonal variability, with a maximum in spring and a minimum in summer. Most of the discarded biomass (almost 96%) were of species with no commercial interest. Within these, the most represented group was elasmobranchs, making up to more than 50% of total discarded biomass. Our findings show that the landing obligation established by the EU will have a low impact in mitigating discards in this fishery, as the vast majority of discards are non-commercial species that are not specified in the regulation. Alternative management strategies, such as a temporary fishery closure in spring (when the discard ratio reaches its maximum), should be considered in order to preserve the vulnerable ecosystem hosted by the submarine canyon.

The rapidly changing climate is pushing the Greenland fishing footprint northwards. With bottom fisheries moving into hitherto unmapped areas, large knowledge gaps regarding the environment in which the fishery takes place ensue. Mapping sediment in these areas is a time consuming and expensive task. Recognizing that fishers have considerable local ecological knowledge can help bridge this knowledge gap. A workshop including ship masters and factory managers on factory trawlers was conducted in order to understand how their knowledge transpired when mapped. This knowledge was compared to historical data and recent bottom photos to develop a better understanding of the differences and similarities between the methods used. The fishers had a good knowledge of sediment types; further some fishers expressed that the topography has changed over time due to intensive trawling. Even though this fishery is undertaken in a high technology environment on large trawlers, the long-time experience of the fishers can contribute to large scale knowledge of marine landscapes. These results are useful when mapping sediments in the future and can also provide a basis for further investigations of changing topography due to trawling. [ABSTRACT FROM AUTHOR]

Abstract: The features of the biology and spatial distribution of northern rock sole Lepidopsetta polyxystra are described based on the analysis of samples from bottom trawlings in the northwestern part of the Bering Sea at depths of 57−440 m in June-August 1996-2001. [ABSTRACT FROM AUTHOR]

The discard and its losses is an important issue with the principles of sustainable and responsible fishery for researchers and the fishing technology. In this study, discard fate, which is caught and released into the sea by discarding in the Iskenderun Bay trawl fishery, was investigated. Small individuals of Nemipterus randalli (N: 340), Sparus aurata (N: 236) and Pagellus erythrinus (N: 148) with low economic value were evaluated as discard fish in the commercial trawl fishery. In order to estimate survival rates, the three fish species individuals were taken to observation tanks on the fishing vessels and waited for 30 minutes after trawl was hauled. In addition to, barotrauma treatment experiments were carried out with a formed pressure tank which produces the pressure gradient at the depth where the species is caught. Barotrauma treatment has been providing a significant contribution to increase the discard survival rate. In particular, it was observed that barotrauma treatment significantly contributed to the survival rate of the N. randalli individuals. The discard survival rates of N. randalli, S aurata and P. erythrinus were calculated 53.4%, 65%, 68.1% with barotrauma treatment and 12.9%, 41.8%, 59% with 1 atm respectively. [ABSTRACT FROM AUTHOR]

In the deep sea trawl fishery targeting shrimp (Pandalus borealis) and other cold-water shrimp species, fishers often use a Nordmöre sorting grid ahead of a small mesh codend to avoid bycatch. However, small fish can pass through the grid and are subsequently retained in the codend. This makes shrimp size selection complex and the size-dependent curve for both the shrimp and the bycatch species often exhibits a bell-shaped signature. In this study we developed a new model and method to estimate size selection in this fishery, conducted fishing trials in the Northeast Barents Sea, and applied the new method to quantify the individual and combined size selection of the Nordmöre grid and codend for deep water shrimp and two bycatch species. The size selectivity for both bycatch species showed the expected bell-shaped signature with low retention probability of very small and larger fish. The Nordmöre grid had high passage probability for all sizes, although it decreased slightly for the largest shrimps. The smallest shrimps were released by the codend. [ABSTRACT FROM AUTHOR]

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Minimizing the probability of discards is an important step in mitigating environmental impacts of fishing activities and maximizing economic gains from fish stocks. Although several discard models have been recently developed, current approaches are still unable to robustly adjust to different circumstances (e.g. fishery target species, geographical location), and lack a closer interaction with stakeholders. Here, we present a novel approach consisting of a modular Bayesian model, which can incorporate any relevant explanatory variable, independently of data availability. The relationships between the variables and discard rates are initially delineated by stakeholders through surveys, and included to the model as priors. The priors are then used together with observed data for estimating posterior distributions of discard probability. We test this approach in two study areas at the Mediterranean Sea: the Ligurian and Tyrrhenian Seas in Italy, and the Greek part of the Aegean Sea. For each site, we evaluated the model for estimating discards from bottom trawl fishery associated with European minimum conservation reference size regulations, as well as discards caused by the low economic value of catches. [ABSTRACT FROM AUTHOR]

In South Africa's most valuable fishery, the offshore demersal hake trawl, participant companies differ in their rightsholdings, product streams, core business structure and their numbers and types of vessels. HakeSim, an agent-based model of this fishing industry, is used to explore these interactions, how companies could cope with increased fuel prices, and to provide insight into profit-risk trade-offs and vulnerabilities of companies. Apart from increasing catch per unit effort (CPUE), which is often detrimental to fish stocks, fuel price increases could be offset by increasing hake market value, achieved by processing fish to higher value end products with a lower catch cost per tonne. Industry's present fleet size and composition is demonstrated to result from profit-risk trade-offs: the flexibility to respond to mismatches between total allowable catch and CPUE, market demands for frozen and fresh product types, and environmental variability. Smaller companies have less risk-averse strategies and are more vulnerable to uncertainty in catches than larger companies, which may explain ongoing trends in consolidation in the industry. Increasing the proxy for environmental uncertainty increased risk to all companies without increasing profits. Incorporating more realistic environmental effects and feedbacks with industry in HakeSim could be an exciting future direction. [ABSTRACT FROM AUTHOR]

Almost all of the world's fisheries overlap spatially and temporally with foraging seabirds, with impacts that range from food supplementation (through scavenging behind vessels), to resource competition and incidental mortality. The nature and extent of interactions between seabirds and fisheries vary, as does the level and efficacy of management and mitigation. Seabird dietary studies provide information on prey diversity and often identify species that are also caught in fisheries, providing evidence of linkages which can be used to improve ecosystem based management of fisheries. However, species identification of fish can be difficult with conventional dietary techniques. The black-browed albatross (Thalassarche melanophris) has a circumpolar distribution and has suffered major population declines due primarily to incidental mortality in fisheries. We use DNA metabarcoding of black-browed albatross scats to investigate their fish prey during the breeding season at six sites across their range, over two seasons. We identify the spatial and temporal diversity of fish in their diets and overlaps with fisheries operating in adjacent waters. Across all sites, 51 fish species from 33 families were identified, with 23 species contributing >10% of the proportion of samples or sequences at any site. There was extensive geographic variation but little inter-annual variability in fish species consumed. Several fish species that are not easily accessible to albatross, but are commercially harvested or by-caught, were detected in the albatross diet during the breeding season. This was particularly evident at the Falkland Islands and Iles Kerguelen where higher fishery catch amounts (or discard amounts where known) corresponded to higher occurrence of these species in diet samples. This study indicates ongoing interactions with fisheries through consumption of fishery discards, increasing the risk of seabird mortality. Breeding success was higher at sites where fisheries discards were detected in the diet, highlighting the need to minimize discarding to reduce impacts on the ecosystem. DNA metabarcoding provides a valuable non-invasive tool for assessing the fish prey of seabirds across broad geographic ranges. This provides an avenue for fishery resource managers to assess compliance of fisheries with discard policies and the level of interaction with scavenging seabirds.

Greenland halibut (Reinhardtius hippoglossoides) is a commercially important species in the northeast Atlantic trawl fishery. However, direct fishing for it is not allowed and it can only be harvested as bycatch. We investigated for the first time the size selection of Greenland halibut in a newly developed double steel grid system designed for the cod and haddock bottom trawl fishery. In this sorting system the first grid (lower grid) replaced the lifting panel present in the traditional Sort-V single grid system often applied in the fishery. Thus, it contributed to the fish sorting process and simultaneously guided fish to the second grid (upper grid). However, the results showed that nearly all Greenland halibut escapees left through the second grid. The release efficiency of the first grid was estimated to be low, and only 11% of the Greenland halibut entering the grid zone made contact with this grid in a way that provided a size-dependent release probability. In contrast, the estimations showed that all Greenland halibut, still in the gear after the first grid, made contact with the second grid. However, this contact was suboptimal for size selection of most individuals, as the estimated 50% retention length (based on the morphology of Greenland halibut) was below the expected value. Comparison of the release efficiency of the new double grid system relative to that of the grid systems used in the fishery today revealed that the new system did not improve the release of undersized Greenland halibut. Moreover, we found that the existing Sort-V single grid system released significantly more Greenland halibut than the new double grid system. [ABSTRACT FROM AUTHOR]