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Establishing marine species distributions is essential for guiding management and can be estimated by identifying potential favorable habitat at a population level and incorporating individual‐level information (e.g., movement constraints) to inform realized space use. In this research, we applied a combined modeling approach to tracking data of adult female and juvenile South American sea lions (Otaria flavescens; n = 9) from July to November 2011 to make habitat predictions for populations in northern Chile. We incorporated topographic and oceanographic predictors with sea lion locations and environmentally based pseudo‐absences in a generalized linear model for estimating population‐level distribution. For the individual approach, we used a generalized linear mixed‐effects model with a negative exponential kernel variable to quantify distance‐dependent movement from the colony. Spatial predictions from both approaches were combined in a bivariate color map to identify areas of agreement. We then used a GIS‐based risk model to characterize bycatch risk in industrial and artisanal purse‐seine fisheries based on fishing set data from scientific observers and artisanal fleet logs (2010–2015), the bivariate sea lion distribution map, and criteria ratings of interaction characteristics. Our results indicate population‐level associations with productive, shallow, low slope waters, near to river‐mouths, and with high eddy activity. Individual distribution was restricted to shallow slopes and cool waters. Variation between approaches may reflect intrinsic factors restricting use of otherwise favorable habitat; however, sample size was limited, and additional data are needed to establish the full range of individual‐level distributions. Our bycatch risk outputs identified highest risk from industrial fisheries operating nearshore (within 5 NM) and risk was lower, overall, for the artisanal fleet. This research demonstrates the potential for integrating potential and realized distribution models within a spatial risk assessment and fills a gap in knowledge on this species' distribution, providing a basis for targeting bycatch mitigation outreach and interventions. [ABSTRACT FROM AUTHOR]

This study identified the overlap between artisanal fishing areas and the Franciscana dolphin (Pontoporia blainvillei) in the Southwest Atlantic Ocean (SWAO), Brazil, to identify areas where the species was incidentally captured from the perception of artisanal fishers. Using a semistructured questionnaire, ethnographic interviews (n = 330) were carried out from 2012 to 2018 with fishers from ten communities in southeastern (ES and RJ) and southern (PR) Brazil. After the interviews, the fishers presented their fishing routes, locations and areas of incidental capture and occurrence of the Franciscana dolphin. Ninety-five fishers (29%) identified the species: 23 in northern ES, 1 in southern ES, 20 in northern RJ, and 51 in the PR. Among the 235 fishers who could not identify the species, approximately half worked in the distribution gaps. The areas of occurrence noted by the fishers coincided with those described in the “National Action Plan for the Conservation of the Toninha,” an official document from the Brazilian Government and scientific literature. The results indicate that the information provided by fishers is useful for understanding the distribution of the Franciscana dolphin and can be used in the development of management strategies to mitigate the incidental capture of the species. [ABSTRACT FROM AUTHOR]

One of the biggest threats to the world’s fish stocks is trawling with indiscriminate capturing of non-target organisms, typically referred to as bycatch. Some species of seahorses are globally threatened and are often targets caught as bycatch. The aim of this work is to describe the magnitude of bycatch of the Patagonian seahorse Hippocampus patagonicus (Sygnathidae) in trawling fisheries in the Southeast and South Brazil. Between 2016 and 2018 we monitored the catch of five trawling vessels off the coast of Rio de Janeiro and Sao Paulo. A total of 2,041 individuals of H. patagonicus were captured, 1,183 males and 858 females. They were evaluated as for injuries suffered during dragging. The average rate of body damage was 33%. Based on the individuals captured and the analysis of on-board maps, an average CPUE of 3.36 with a standard deviation of 5.95/ind./day/vessel was estimated for the study area, extrapolating an incidental removal of 2,282,515 individuals per year, or 9,427 metric tons of seahorses, along the South and Southeast Brazil, where 3700 trawlers operate, an area recognized as the geographic distribution of H. patagonicus in Brazil

Simple Summary: Marine mammals are known to interact with fisheries worldwide, usually in the form of depredation which is the act of removing captured fish or bait from fishing gear. Depredation can significantly damage fishing gear and catch, thus increasing operating costs. Additionally, such interactions may lead to the incidental capture of marine mammals with consequences that may lead to injury and death. The endangered Mediterranean monk seal has been known to interact with small-scale fisheries in the Mediterranean Sea, with consequent negative impacts on the species and fishermen. While the population of the species has steadily grown to about 20 individuals in Cyprus in the past 12 years, the Mediterranean monk seal is currently facing different anthropogenic stressors. Interviews were conducted with 90 fishermen with the aim to get a better understanding of the interactions between the Mediterranean monk seal and small-scale fisheries in the Republic of Cyprus. The findings indicate minimal interactions between the monk seals and fisheries, but it is likely that the species may accidentally become entangled on fishing gear, potentially leading to adverse consequences and mortality. This study proposes specific area- and time-based protected areas as a management action to mitigate against these interactions. Interactions between fisheries and marine mammals have been well documented in almost all existing fishing gears around the world, often associated with detrimental consequences. Interactions of the endangered Mediterranean monk seal (Monachus monachus) with small-scale fisheries have been previously documented in the Mediterranean; this is a problem that seems to be growing in recent years. The present study aims to understand for the first time the nature and extent of interactions between the Mediterranean monk seal and small-scale fisheries in the Republic of Cyprus. The data were collected by conducting in-person semi-structured interviews, between November and December 2020, with 90 fishermen operating from nine different ports, extending throughout the entire coastline of the Republic of Cyprus. The results revealed minimal interactions between the Mediterranean monk seals and small-scale fisheries. The findings indicate that interactions are more likely to occur at depths of less than 10 m, closer to the coast, with the use of trammel nets and gillnets, and during the spring and summer months. The encounter, depredation and incidental capture rates were calculated at 0.01 (0.95%), 0.005 (0.51%) and 0.0004 (0.04%) per fisher, respectively. Spatiotemporal closed areas are proposed as a potential solution to mitigate these interactions. [ABSTRACT FROM AUTHOR]

Sharks and rays are among the most threatened vertebrates, mostly due to commercial fisheries. Data on incidental capture is sparse, but it is estimated that about 50% of reported global catches of elasmobranchs are from bycatch. Elasmobranchs are captured in a variety of fishing gear throughout the world. One promising strategy to minimize incidental catches is the release of live sharks and rays. However, so far, no critical analysis had been carried out to assess the importance of release as a measure to mitigate the impacts of bycatch. Results indicated that despite onboard releases being cited in Plans of Action (along ZEEs) and recommendations/regulations of Regional Fisheries Management Commissions (in international waters), this measure is treated as secondary and has voluntary adherence, which can significantly reduce its efficiency. Moreover, among the Best Fishing Practice Manuals currently available, although release is cited as a priority, most of them do not consider the dynamics of the location/fishing modality for which it was developed. A change on how release is perceived is needed to prioritize this conservation strategy, as well as its potential as a social tool to reduce the impacts of bycatch on sharks and rays. [ABSTRACT FROM AUTHOR]

Abstract This study compares local ecological knowledge (LEK) of fishers from the Southwest Atlantic Ocean (SWAO), Brazil, related to the franciscana dolphin (Pontoporia blainvillei). We conducted 330 ethnographic interviews in ten fishing communities in southern and southeastern Brazil between 2012 and 2018. Boolean or Classic Logic was used to identify 95 fishers who were able to recognize the franciscana dolphin accordingly to the taxonomic entity P. blainvillei: 23 in northern Espírito Santo state, one in southern Espírito Santo, 20 in northern Rio de Janeiro state, and 51 in northern Paraná state. Among these 95 fishers, 87.4% (n = 83) reported incidental captures in fishing nets. Among these, 52 (54.7%) did not know any solution to this problem. Interviews revealed that the fishers usually discard carcasses in the sea after fat and muscle tissue are removed so that they can be used as bait for shark fishing or as food. In Southeastern Brazil, fishers LEK related to their ability to identify franciscana dolphin varied from ‘no identification’ and ‘extremely low identification’ to ‘partial’ and ‘good identification,’ while in southern Brazil, fishers mainly presented a ‘good identification’ of the dolphins. We propose comanagement actions to conserve the franciscana dolphin in the SWAO.

Sea turtles are susceptible to a wide range of impacts. In Brazil, the loggerhead turtle Caretta caretta (Linnaeus, 1758) is the main sea turtle species caught incidentally by longline fishing fleets that target the blue shark Prionace glauca (Linnaeus, 1758) and swordfish Xiphias gladius (Linnaeus, 1758). The latter is well known for its predation strategy, which consists of using the rostrum to injure and catch prey. In this study, we recorded for the first time the impalement of a juvenile loggerhead sea turtle by a swordfish during a fishing operation of a Brazilian longline vessel in 2018. Two videos of this interaction were recorded by the shipmaster around 260 km from the Brazilian coast. The sea turtle was incidentally caught with a hook and subsequently attacked by the swordfish. The rostrum initially pierced the anterior left shoulder of the turtle and passed through the body, exiting from the right posterior carapace. Given the position of the attack, considerable internal damage was most certainly done to the turtle. Although the turtle was hauled aboard to remove the hook and then returned to the sea alive, it probably died due to the extent of the injuries caused by the rostrum having passed through the center of the body. Since both swordfish and turtle are pelagic and these interactions are poorly recorded, such encounters may be relatively common. Therefore, this type of information should be included in the data collection protocols of fishery monitoring programs to better understand and scale the bill-stab phenomenon, not only for sea turtles but also in relation to other groups of fauna.

Shrimp trawling has crucial socioeconomic value worldwide, and its relevance is even more direct in artisanal fishing communities that depend on shrimp for survival. This fishing activity is also recognized for different environmental impacts such as marine overfishing, the incidental catch of species, or destruction of the benthic zone by trawling the net on the seafloor. In Brazil, the closed season protects commercial shrimp stocks from extinction. However, this period does not consider the different species that constitute the accompanying fauna of this fishery. Many studies point to the importance of traditional knowledge and environmental perception of local fishers in discussions about sustainability and fisheries management actions. This work aimed to evaluate the dynamics of fishing, ethnobiological knowledge, and environmental perception, especially concerning the accompanying fauna of artisanal shrimp trawler fishers in Macaé, Rio de Janeiro. Between June 2017 and January 2018, 31 semi-structured interviews were conducted. Questions about the fishers' sociodemographic, professional experience, ethnobiological knowledge, and environmental perception were applied. Most of the interviewees were between 40 and 50 years old, with incomplete elementary education and 20 years of experience in artisanal shrimp fishing. The fishers do not identify the incidental catches they make during trawl fishing as an impact. They see the closed season as an essential measure for the sustainable use of fishery resources. In contrast, they disagree about the period, which they consider misplaced. Fishers' perceptions indicate Macaé needs more effective actions to reduce the capture of accompanying fauna, environmental education programs, and more involvement of fishers in the choices and implementation of management measures. [ABSTRACT FROM AUTHOR]

Bycatch is the most significant threat to marine megafauna (sea turtles, marine mammals, elasmobranchs, seabirds) worldwide, and the leading cause of the decline of several cetacean species. The bycatch issue in the Indian Ocean is poorly understood, but high bycatch levels in gillnet fisheries have been documented for the past two decades, in both small‐scale and semi‐industrial fisheries. Unfortunately, methods to reduce bycatch are often unavailable, financially non‐viable or socially unacceptable to fishermen.Using a network of trained boat captains in the tuna drift gillnet fishery in the Arabian Sea, targeted catch and bycatch data were collected from 2013 to 2017 off the coast of Pakistan (northern Indian Ocean). Two fishing methods using multifilament gillnets were used: surface deployment and subsurface deployment (i.e. headline of net set below 2 m depth).Predicted catch rates for targeted species did not differ significantly between the two fishing practices, although a drop in tuna (6.2%) and tuna‐like (10.9%) species captures was recorded in subsurface sets. The probability of cetacean bycatch, however, was 78.5% lower in subsurface than in surface sets.Cetacean bycatch in tuna drift gillnet fisheries has the potential to be significantly reduced at a relatively low cost for fishers. However, further research with an appropriate sampling design and a large sample size is required to confirm the efficacy of the proposed mitigation method. The acceptability and adoption of subsurface setting by fishers also needs to be further investigated. Despite some limitations, this preliminary study also highlights the importance of crew‐based observer data as an alternative source of data when observers cannot be deployed on fishing vessels. [ABSTRACT FROM AUTHOR]

During 2010–2015, the Mississippi Sea Turtle Stranding and Salvage Network (STSSN) documented 1,073 sea turtles, primarily juvenile Kemp’s ridleys (Lepidochelys kempii), incidentally caught by recreational anglers. Due to increases in interactions, an angler interview survey was conducted during 2013 at six Mississippi fishing piers. Anglers were interviewed about fishing practices and sea turtle interactions. Interviewers conducted outreach and distributed Rehabilitation Hotline business cards. Angler participation was 86%, and over 60% used J-hooks and were not targeting specific species, which was similar to data collected from incidental captures reported to the STSSN. Over 58% of anglers used dead shrimp followed by cut up fish for bait. This greatly differs from STSSN reported captured sea turtles where 60% were caught on cut up fish and only 6% on dead shrimp. Over 18% of participants captured at least one sea turtle in the last 12 months. Anglers stated that nearly half of the sea turtles were taken for rehabilitation, 41% were released by the angler and 10% broke the line and swam away. Only 60% of anglers reported the capture because many were unaware they should report it. During and after the survey period, there was an increase in reported incidental captures, possibly indicating outreach is an effective means of increasing awareness and reporting. Recently, NOAA Fisheries developed a survey that can be used nationally to conduct similar research. We recommend conducting angler surveys every few years unless there is a noticeable change in incidental capture trends or angler practices.

In Brazil, five species of sea turtles use the region for feeding and reproduction. For these endangered species, one of the biggest impacts on their populations is incidental catches in fishing gear.In the state of Santa Catarina (SC) ‐ Brazil, fishing is an important economic activity, with distinct and numerous industrial and artisanal fleets. These fleets incidentally capture all five species of sea turtle.In the Canoa beach fishing community in the municipality of Barra Velha (SC), gillnet fishing holds great economic and cultural importance. The four main gillnet fisheries in this community are whitemouth croaker, leatherjacket/mackerel, hake, and grouper/catfish/flounder, the latter of which is carried out on rocky bottoms and is locally called 'malhão'. In this fishery, fishermen have reported catching sea turtles over the years, especially the green turtle Chelonia mydas.In the present study, 1,998 sets were monitored between September 2010 and April 2011, of which 104 (5.2%) were of gillnets for whitemouth croaker Micropogonias furnieri; 324 (16.2%) were for leatherjackets Oligoplites spp. and mackerel Scomberomorus spp.; 1,261 (63.1%) were for hake Cynoscion spp.; and 309 (15.5%) were for grouper Epinephelus spp., catfish Genidens spp., and flounder Paralichthys spp.Considering all fisheries, the incidental capture of sea turtles occurred in only 3% of the monitored sets. In all, 87 sea turtles were captured, 78 (89.6%) of which were recorded in the 'malhão'. Of these captures, 68 (87.2%) were C. mydas, eight (10.2%) were loggerhead turtle Caretta caretta and two (2.6%) were 'hard‐shelled' turtles.The direct mortality rate observed for C. mydas in the 'malhão' was 73.5%, which is the highest rate recorded in similar fisheries of the south‐west Atlantic, thus raising concern for the protection of this species in the Atlantic Ocean. [ABSTRACT FROM AUTHOR]

To investigate factors contributing to immediate mortality in gill-net-caught elasmobranchs, we caught and blood sampled a total of 64 sharks and rays. Blacktip reef sharks (Carcharhinus melanopterus) were the most commonly caught species and had significantly elevated plasma lactate (mean 23.3 mM) and potassium (mean 6.2 mM) concentrations following capture, suggesting physiological disturbance. The overall immediate mortality rate of C. melanopterus was 38% and mortality was significantly influenced by body size, but not location of entanglement or sex. Of the other species caught, nervous sharks (Carcharhinus cautus) were of particular concern, because this species is often caught as bycatch by gill-net fisheries throughout its range and experienced high immediate mortality rates when captured (66%; n = 12) in the present study. The results suggest that juvenile C. melanopterus are particularly susceptible to gill-netrelated mortality and that fisheries management strategies for C. melanopterus bycatch should focus on reducing the likelihood of juvenile sharks encountering this gear. Given that this species is not currently considered to be threatened with extinction, population monitoring should be performed such that the suggested regulations can be implemented if populations decline to levels threatening the conservation status of the species. [ABSTRACT FROM AUTHOR]

Sea turtle populations underwent severe decline in historical times, mainly through harvesting eggs and adults on nesting beaches. With the reduction of this threat in many areas, coupled with other conservation actions, some populations have demonstrated encouraging recovery, although remaining below their previous levels and undergone additional modern threats such as incidental capture in fisheries and pollution. Trends in sea turtle populations have usually been assessed through monitoring of females or nests on nesting beaches. Here we present data from a 22-year monitoring period for a juvenile green sea turtle Chelonia mydas mixed-stock in southeastern Brazil that were incidentally captured in passive non-lethal pound nets. A total of 3639 green turtles were captured in 5323 fishing days.pound −1 with mortality rate of 2%. Captures occurred in all months, but bycatch rates, excluding recapture events, were higher in September and October, probably due to the recruitment of turtles migrating from southern areas, as well as recruits from the oceanic zone. Capture rates increased by 9.2% per year in the period from 1995 to 2016, in line with increasing source populations, particularly the main source contributor at Ascension Island, but also Trindade Island (Brazil) and Aves Island (Venezuela). Mean Curved Carapace Length of green turtles was higher during austral summer/early autumn and decreased markedly in May, probably due to the small-sized individuals that recruited to the study site. We show that the incidental capture of sea turtles in non-lethal fisheries, such as Brazilian pound nets, could also provide data on trends of populations nesting in distant places, and can contribute to the assessment of population status of sea turtles within Regional Management Units throughout the Atlantic Ocean. [ABSTRACT FROM AUTHOR]

Fishing has a great importance to the socioeconomic development of the Amazonian riparian communities, which have a local knowledge on the environment, its fauna and flora. This knowledge is of paramount importance for the management and conservation of fish stocks and species that interact with the fishing activity, such as the populations of gray porpoises (Sotalia sp.) and pink porpoises (Inia geoffrensis). Therefore, to register local ecological knowledge and the interaction of porpoises with fishing on the coast of the state of Para, Brazil, 82 semi-structured interviews were carried out in 3 different colonies of fishermen: colony Z-1 (Soure), colony Z-7 (Maracana), and colony Z-23 (Colares). The species Sotalia sp. had a strong social structure, it can be observed in the region both during the dry and rainy seasons, while the species I. geoffrensis didn’t present a social structure, it’s observed in the region especially during the rainy season. The pink porpoise showed a larger interaction with fishing than the gray porpoise, however, this interaction was particularly detrimental to the activity, while the gray porpoise showed both a beneficial and a harmful interaction with fishing. The incidental capture of porpoises primarily occurred through nets and trawls, harming their populations. Captured animals were mostly released, however, there were records of consumption for food, use as bait, and selling of the animal’s eyes. This information will constitute the basis for further studies on the biology, ecology, and estimate of the mortality of porpoises on the Amazon coast. Management measures should be adopted, along with the communities studied, for the conservation of these animals in the region.

Surface longline gears are used to fish different species, mainly albacore Thunnus alalunga (Bonnaterre, 1788), bluefin tuna Thunnus thynnus (Linnaeus, 1758), and swordfish Xiphias gladius Linnaeus, 1758, and are considered highly dangerous for threatened marine turtles. Loggerheads Caretta caretta (Linnaeus, 1758) can be incidentally captured by surface longlines. A number of captured individuals die during the fishing operation, which we consider direct mortality due to fishing. We analysed the relative loggerhead by-catch and direct mortality associated with each type of boat and gear from April to December during the period 1999-2004 in the Spanish surface longline fleet that fishes in the western Mediterranean Sea, an important fishing area for this fleet. We used different indices to compute the catch per unit effort (CPUE) according to the number of hooks and to the number of fishing operations for each type of boat and gear. Both by-catch and direct mortality differed significantly according to the type of boat and gear. With respect to the number of hooks, boats longer than 12 m not using a roller and targeting bluefin tuna captured the highest number of loggerheads, whereas boats longer than 12 m with a roller that targeted swordfish caused the highest direct mortality. With respect to the number of fishing operations, boats longer than 12 m without a roller that targeted albacore captured the highest number of loggerheads; the highest direct mortality was caused by this type of boat and by boats longer than 12 m using a roller and targeting swordfish.

The western Mediterranean Sea is an important fishing area for the Spanish drifting longline fleet, targeting swordfish (Xiphias gladius), bluefin tuna (Thunnus thynnus) and albacore (T. alalunga). Some seabird species can be captured incidentally as bycatch marine fauna. From July 1999 to August 2000 information on 554 surface longline sets was collected by onboard observers of the Spanish Oceanographic Institute (IEO) on 18 longline fishing boats working within the Spanish Mediterranean fishing area. Eleven yellow-legged gulls (Larus cachinnans), 9 Cory´s shearwaters (Calonectris diomedea) and 1 Northern gannet (Morus bassanus) were captured incidentally. Bycatch rates ranged from 0.002 to 0.023 birds/1000 hooks.

Dugongs (Dugong dugon) are threatened by incidental capture in small-scale fisheries, but other static underwater structures could present a similar entanglement risk. In December 2013, an adult male dugong was entangled in the ropes of a seaweed farm in Busuanga, Palawan, Philippines, and drowned. Anecdotal reports of similar incidents suggest that this was not an isolated occurrence. Given that dugong populations are slow to reproduce and cannot sustain even low levels of mortality, effective marine spatial planning is essential to minimize overlap between dugong habitat and mariculture operations. [ABSTRACT FROM AUTHOR]

Seabird bycatch represents one of the main threats to vulnerable seabird populations, particularly albatross and petrels, and requires urgent conservation management interventions at a global scale. We studied seabird mortality associated with demersal factory trawl vessels that target Argentine Hake Merluccius hubbsi along the Argentine Patagonian Shelf and tested the efficacy of bird-scaring lines as a seabird bycatch mitigation measure. From November 2008 to June 2010, dedicated seabird observers recorded three sources of seabird mortality: entanglements with the trawl net; collisions with the trawl cables (corpses hauled aboard); and collisions with trawl cables (birds observed killed or injured). During 141 days and 389 hauls, we recorded 17 seabird species associated with vessels, ten of which interacted with fishing gear. The most vulnerable species was the black-browed albatross ( Thalassarche melanophris). From 41 recovered corpses, we identified black-browed albatross mortality rates of 0.013 and 0.093 birds/haul for net entanglement and cable collision (corpses hauled aboard), respectively. From counts of birds killed or injured by cable collisions, we estimate a black-browed albatross mortality rate of 0.237 birds/h. We use official fishing effort data to consider the potential scale of seabird mortality for the entire fleet and identify the main factors contributing to seabird mortality in this fishery. Bird-scaring lines eliminated seabird mortality caused by collisions with trawl cables and are recommended as a short- to medium-term measure to mitigate seabird mortality in this fishery. [ABSTRACT FROM AUTHOR]

This paper presents the first by-catch assessment focussed on mobulid rays in pelagic longline fisheries based on on-board scientific observer data (1998-2013) over the south-western Atlantic. Mobulid diversity,as well as their catch distribution and disposition, were investigated. Mobulid by-catch frequency was low, but by-catch probability increased at lower bottom depths (i.e. continental shelf and slope), higher fishing effort and during the warm period (summer-autumn). Photographic and video records allowed the identification of two devil ray species, the spinetail devil ray (Mobula japanica) and the bentfin devil ray (Mobula thurstoni), but the number of species interacting with longliners in the region could also be greater. Southernmost captures of both species (368S) exceed previous reported records by almost 128, therefore greatly expanding their known distribution ranges towards southern waters in the south-western Atlantic. Mobulids were never retained on board, and most of them were released alive. However, hooks were often not removed from their bodies and on several occasions fishermen caused injuries while trying to cut the branch line, so some uncertainty remains regarding their post-capture mortality. More specific studies that assess these particular aspects are needed to better understand the potential effect of longline fisheries on mobulid populations. [ABSTRACT FROM AUTHOR]

The article presents a study about the impact of trawling and the absence of selectiveness of fishing gear to the incidental capture of discarded species at the artisanal fishery in the Gulf of California, Mexico. It highlights the abundance of flatfishes caught as bycatch in bottom-trawls that cause fishing pressure. It cites several types of flatfishes including Paralichthys woolmani, Etropus crossotus, Citharichthys fragilis, Citharichthys gilberti, Achirus mazatlanus and Syacium ovale.

On October 1, 2009, sixteen dolphins were obtained from fishermen by incidental catching in the Yellow Sea, China. As the dolphins' skin color was ambiguous, morphological parameters were measured, and mitochondrial DNA cytochrome b (Cyt b) gene sequence was studied to identify the species. Morphological characteristics were consistent with Pantropical spotted dolphins, Stenella attenuata. Furthermore, a partial mitochondrial DNA cytochrome b (Cyt b) gene sequence as long as 328-bp was studied by extracting genomic DNA from the skins, and six haplotypes were detected in the sixteen dolphins. By comparing homologous sequences available in GenBank (), all the six haplotypes had maximal genetic similarity with Pantropical spotted dolphin. Eight species of cetacean (whales and dolphins) are now recognised in the Yellow Sea. To the best of our knowledge, this is the first record of Pantropical spotted dolphins from this region. Despite this species being listed as a Grade II National Key Protected Animal since 1988, little is known of its biology in Chinese waters. We recommend remedial research be undertaken to ensure appropriate management. [ABSTRACT FROM AUTHOR]

Life-history variables for three incidentally captured species of seahorse (Kellogg's seahorse Hippocampus kelloggi, the hedgehog seahorse Hippocampus spinosissimus and the three-spot seahorse Hippocampus trimaculatus) were established using specimens obtained from 33 fisheries landing sites in Peninsular Malaysia. When samples were pooled by species across the peninsula, sex ratios were not significantly different from unity, and height and mass relationships were significant for all species. For two of these species, height at physical maturity ( HM) was smaller than the height at which reproductive activity ( HR) commenced: H. spinosissimus ( HM = 99·6 mm, HR = 123·2 mm) and H. trimaculatus ( HM = 90·5 mm, HR = 121·8 mm). For H. kelloggi, HM could not be estimated as all individuals were physically mature, while HR = 167·4 mm. It appears that all three Hippocampus spp. were, on average, caught before reproducing; height at 50% capture ( HC) was ≥ HM but ≤ HR. The results from this study probe the effectiveness of assessment techniques for data-poor fisheries that rely heavily on estimates of length at maturity, especially if maturity is poorly defined. Findings also question the sustainability of H. trimaculatus catches in the south-west region of Peninsular Malaysia, where landed specimens had a notably smaller mean height (86·2 mm) and markedly skewed sex ratio (6% males) compared with samples from the south-east and north-west of the peninsula. [ABSTRACT FROM AUTHOR]

In the Western Brazilian Amazon, interactions of boto (Inia geoffrensis) and tucuxi (Sotalia fluviatilis) dolphins with fishing activities are common, but the prevalence of incidental/intentional catches is not known. This article describes incidental mortality events and intentional killing of I. geoffrensis and S. fluviatilis entangled in artisanal fishing gear and the opportunistic use of carcasses as bait. Between October 2010 and November 2011, surveys were conducted in waters of the lower Japurá River, between the Mamirauá and Amanã sustainable development reserves. In order to obtain information on interactions and to try to establish a stranding/entanglement response program (SERP), informal conversations were exchanged with local inhabitants (n = 174). Intense carcass-search surveys (n = 171) along the river in the four hydrological seasons (e.g., low, rising, high, and falling waters) were conducted, comprising a total of 1,197 h of sampling effort. Twenty-five dolphin-fishing interaction events were recorded (11 I. geoffrensis and 14 S. fluviatilis), 19 in 2011 and six in 2012 (through SERP). A total of 11 necropsies (three I. geoffrensis and eight S. fluviatilis) were performed. Four individuals (two I. geoffrensis and two S. fluviatilis) exhibited evidence of physical violence before death, and two (one I. geoffrensis and one S. fluviatilis) died in abandoned gillnets. Two intentional killing events of I. geoffrensis incidentally entangled for bait use in the piracatinga (Calophysus macropterus) fishery were reported by fishermen, while three carcasses (two I. geoffrensis and one S. fluviatilis) with gillnet marks were also used in that activity. At least six of the S. fluviatilis entanglement events occurred in fishing gear used for tambaqui (Colossoma macropomum) and pirapitinga (Piaractus brachypomus) (90/100-mm mesh-size gillnet), two of the most important commercial fish species in the Amazon Basin. As seasonal fishing constitutes the main income for riverine human populations, the negative reactions that cetacean presence causes to people could have a catalyst effect for the transition from "incidental capture" to "intentional capture and competitor removal." Law enforcement and precautionary measures through good fishing practices inside dolphin critical foraging areas should be taken together with fisheries' managers and fishermen to start to develop multiple-species management and ensure sustainable fishing practices. [ABSTRACT FROM AUTHOR]

Fisheries are recognised as a major threat to sea turtles worldwide. Oceanic driftnets are considered the main cause of the steep decline in Pacific Ocean populations of the leatherback sea turtle Dermochelys coriacea. The world's largest leatherback population nests in West Africa and migrates across the Atlantic Ocean to feed off the South American coast. There, the turtles encounter a range of fisheries, including the Brazilian driftnet fishery targeting hammerhead sharks. From 2002 to 2008, 351 sea turtles were incidentally caught in 41 fishing trips and 371 sets. Leatherbacks accounted for 77.3% of the take ( n = 252 turtles, capture rate = 0.1405 turtles/km of net), followed by loggerheads Caretta caretta (47 individuals, capture rate = 0.0262 turtles/km of net), green turtles Chelonia mydas (27 individuals, capture rate = 0.0151 turtles/km of net) and unidentified hard-shelled turtles (25 individual, capture rate = 0.0139 turtles/km of net) that fell off the net during hauling. Immediate mortality (i.e., turtles that were dead upon reaching the vessel, excluding post-release mortality) was similar among the species and accounted for 22.2 to 29.4% of turtles hauled onboard. The annual catch by this fishery ranged from 1,212 to 6,160 leatherback turtles, as estimated based on bootstrap procedures under different fishing effort scenarios in the 1990s. The present inertia in law and enforcement regarding gillnet regulations in Brazil could result in the reestablishment of the driftnet fishery, driving rates of leatherback mortality to levels similar to those observed in previous decades. This development could potentially lead to the collapse of the South Atlantic leatherback population, mirroring the decline of the species in the Pacific. In light of these potential impacts and similar threats to other pelagic mega fauna, we recommend banning this type of fishery in the region. [ABSTRACT FROM AUTHOR]

Skewed adult sex ratio (ASR) has been proposed as a common pattern in birds, frequently biased towards males and with larger biases in globally threatened species. In albatrosses and petrels, it has been suggested that differential mortality of one gender in fisheries is caused either by sexual size dimorphism giving males a competitive advantage, which allows more access of the larger sex (i.e. males) to discards and/or baits, or to at sea segregation of sexes. Here, we tested these hypotheses by determining ASRs in albatrosses and petrels trapped at sea when attending longline fishing vessels for discards in the southwestern Atlantic Ocean, and searched in the literature for patterns in ASR in albatrosses and petrels killed by fisheries in this area and elsewhere. We show that skewed ASR is common in albatrosses and petrels in the community attending vessels for discards, confirming results found for birds in general. There was no correlation between skewed ASR and conservation status, or between ASR and sexual size dimorphism. Our review of the sex of birds incidentally killed in fisheries found skewed ASR toward males, females or parity to be equally reported. Thus, sexual dimorphism in size does not explain skewed ASR in the community we sampled or in incidental captures in fisheries in the review. Differential at-sea distribution of sexes appears to be a better explanation of the patterns found in the community sampled at sea as well as skewed ASR in seabird fatalities, particularly distant from breeding areas. [ABSTRACT FROM AUTHOR]

Abstract: The incidental capture in fisheries is probably the main conservation problem affecting seabirds. While the capture of albatrosses and petrels on longline hooks is well-known worldwide, the bycatch of diving seabirds in gillnets is an overlooked conservation problem. During a winter coastal fishing trip, the capture of Magellanic penguins (Spheniscus magellanicus) was recorded in driftnet and bottom setnet fisheries for the first time in southern Brazil. The highest captures rates were found in driftnets, from 146.5 to 545.5penguins/km2 of net and a total of 56 dead penguins were recorded. In the bottom gillnet, a total of 12 birds were killed and the capture rates varied from 41.7 to 125.0penguins/km2 of net. Although preliminary, the results presented in this paper were consistent between sets. If we consider the magnitude of driftnet and setnet fishing fleets, and that most dead penguins were adults, the impact upon Magellanic penguin populations is probably significant. [Copyright &y& Elsevier]

The article presents a study which examines the effectiveness of circle hooks against the J-type hooks in reducing the bycatches of loggerhead and leatherback sea turtle in the Brazilian pelagic longline fishery in south Atlantic Ocean. It involved an alternating control and experimental hooks scattered along the sections of the mainline from 2004 and 2008. It concludes that circle hooks are effective in the conservation of sea turtles, while increasing the catch rates of main target species.

This study reviews and updates information on cetacean strandings in the state of Ceará, Brazil (02°30′S 41°15′W– 04°30′S 36°45′W), comprising 573 km of coastline. In the years 1992–2005, there were 252 cetacean stranding events, representing 19 species: three species of Balaenopteridae, three Physeteridae, two Kogiidae, two Ziphiidae and 11 Delphinidae. Three species comprised the majority (78.9%) of stranding events: estuarine dolphin, Sotalia guianensis (61.9%); sperm whale, Physeter macrocephalus (10.3%); and rough-toothed dolphin, Steno bredanensis (6.7%). There was an increasing trend in the number of cases reported in the first five years with a highest frequency achieved in 1996. Stranding events occurred throughout the year, with the lowest frequency occurring in the autumn (March–May). Approximately 4% of the events were attributed to natural causes while 24.6% were human-related, mainly incidental captures. Meat removal for human consumption or bait was recorded in 6.7% of events. In the study area, Sotalia guianensis, P. macrocephalus and Steno bredanensis were the most abundant cetacean species, whereas Lagenodelphis hosei, Pseudorca crassidens, Orcinus orca, Kogia sima, Mesoplodon europaeus, Balaenoptera acutorostrata and Balaenoptera bonaerensis are probably rare in the area. [ABSTRACT FROM PUBLISHER]

Since 1991, Projeto TAMAR-IBAMA, the Brazilian sea turtle conservation program, has maintained a station in Ubatuba, State of São Paulo, southeastern Brazil, a feeding area for sea turtles where incidental capture in coastal fisheries occurs. We present an overview of the local fishing methods, explain the conservation approach and field methods employed by TAMAR in the region, present biological data collected between 1991 and 1998, and provide an assessment of the conservation status of sea turtles in the Ubatuba region. During the study period, 2,515 captures of sea turtles were recorded, comprising four species: green turtles (Chelonia mydas, 98.4% of total captures, generally juveniles), loggerheads (Caretta caretta), hawksbills (Eretmochelys imbricata), and leatherbacks (Dermochelys coriacea). Most of the data come from turtles incidentally captured in fishing gear, mainly by artisanal methods. The available data suggest that Ubatuba is a developmental habitat for juvenile green turtles. [ABSTRACT FROM AUTHOR]

The problem of incidental dolphin mortality in the eastern Pacific Ocean fisheries for yellowfin tuna is one of the longest running controversies in the modern international law of fisheries. Although initiatives in the last 30 years have been successful in reducing incidental mortality from very high levels to relatively modest levels, most of these have been either unilateral actions, principally by the United States, or voluntary agreements among the states concerned. In 1998, however, these states concluded a binding agreement that formalized and extended the existing voluntary arrangements. This article reviews the developments that led to the adoption of the 1998 agreement, summarizes its provisions, and looks at events since its adoption. [ABSTRACT FROM AUTHOR]

Green sea turtles (Chelonia mydas) switch habitats during their development, moving from pelagic to neritic areas and then commuting between nesting and foraging grounds during adulthood. Due to their predominantly coastal habitats, they are under a range of anthropogenic threats. We monitored turtles incidentally captured in fishing weirs in Ceará state, northeastern Brazil, over a decade and provided an overview of capture rates in the fishery during previous decades. Between 2008 and 2018, 2335 captures were recorded, 76% were only once. Most recaptures (86%) occurred up to six months after the first capture, with a mean growth rate of 6.7 ± 3.6 cm year−1. Capture rates varied between years, with the highest rates during the historical period, peaking in 1962 (0.16 turtles day weir−1). Between 2008 and 2018, the daily capture rate was 0.07 turtles day weir−1. Similar to other areas, the use of turtles as a fishery resource seems to have reduced population sizes in the Atlantic Ocean. On the other hand, the intensive monitoring of local weirs provided an opportunity to mobilize the community regarding their conservation, which in turn could have supported the recovery of turtles from a number of distant colonies. The relatively constant and year-round capture of green sea turtles reflects the presence of individuals from different rookeries and demonstrates the importance of the region as a developmental ground for juveniles from different nesting areas, with high growth rates compared with other feeding areas. Partnership with local fishermen and the long-term monitoring of passive nonlethal fishing weirs are key tools in supporting sea turtle conservation. • Interdecadal overview of sea turtle captures show influence of conservation actions. • Fishermen behavior towards sea turtle meat consumption changed. • Fishing weirs over 5 m depth capture turtles with curved carapace length >50 cm. • Most recaptures occurred within six months, suggesting regional residence. • In the tropical area, green sea turtles had higher growth rates than elsewhere. [ABSTRACT FROM AUTHOR]

For decades, cetacean bycatch has been a major conservation and welfare concern in the European Union with high numbers of harbour porpoises, dolphins and whales dying each year. Despite binding legal requirements to monitor and reduce bycatch, cetacean bycatch monitoring has been insufficient in most fisheries and areas to generate reliable estimates of bycatch rate. Measures to reduce bycatch have been limited and not always directed at the most problematic fisheries. EU cetacean bycatch legislation (Council Regulation (EC) No. 812/2004) was repealed and replaced by a new Regulation, Regulation on the conservation of fishery resources and the protection of marine ecosystems through technical measures (2019/1241). Whilst some improvements have been made in the new Regulation, scientific advice of the ICES Bycatch Working Group (ICES WGBYC), and other expert regional bodies, such as ASCOBANS and ACCOBAMS, were not incorporated explicitly and some measures in the adopted Technical Measures Regulation weaken both the provisions of the existing cetacean bycatch legislation and the Commission's original proposal. The bycatch measures adopted for cetaceans are not sufficient to mitigate bycatch effectively in European waters. Management solutions to reduce bycatch are identified and a number of general recommendations towards development of national and regional management plans, implementation and enforcement to that end are made. • Cetacean bycatch is a major conservation and welfare concern in the European Union. • Historic regulation is piecemeal and inadequate. • New technical measures provide both opportunities and weaknesses. • Member States should be compelled to meet the requirements of the law. • Enforcement by the European Commission would save many thousands of cetaceans each year. [ABSTRACT FROM AUTHOR]

Bycatch is considered one of the most significant threats affecting cetaceans worldwide. In the North Sea, bottom-set gillnets are a specific risk for harbor porpoises ( Phocoena phocoena ). Methods to estimate bycatch rates include on-board observers, remote electronic monitoring, and fishermen voluntarily reporting; none of these are systematically conducted. Additionally, necropsies of stranded animals can provide insights into bycatch occurrence and health status of individuals. There are, however, uncertainties when it comes to the assessment of bycatch in stranded animals, mainly due to the lack of diagnostic tools specific for underwater entrapment. We conducted a literature review to establish criteria that aid in the assessment of bycatch in small cetaceans, and we tested which of these criteria applied to harbor porpoises retrieved from gillnets in the Netherlands ( n = 12). Twenty-five criteria were gathered from literature. Of these, "superficial incisions," "encircling imprints," and "recent ingestion of prey" were observed in the vast majority of our confirmed bycatch cases. Criteria like "pulmonary edema," "pulmonary emphysema," and "organ congestion" were also frequently observed, although considered unspecific as an indicator of bycatch. Notably, previously mentioned criteria as "favorable health status," "absence of disease," or "good nutritional condition" did not apply to the majority of our bycaught porpoises. This may reflect an overall reduced fitness of harbor porpoises inhabiting the southern North Sea or a higher chance of a debilitated porpoise being bycaught, and could result in an underestimation of bycatch rates when assessing stranded animals.

Large oceanic migrants play important roles in ecosystems, yet many species are of conservation concern as a result of anthropogenic threats, of which incidental capture by fisheries is frequently identified. The last large populations of the leatherback turtle, Dermochelys coriacea, occur in the Atlantic Ocean, but interactions with industrial fisheries could jeopardize recent positive population trends, making bycatch mitigation a priority. Here, we perform the first pan-Atlantic analysis of spatio-temporal distribution of the leatherback turtle and ascertain overlap with longline fishing effort. Data suggest that the Atlantic probably consists of two regional management units: northern and southern (the latter including turtles breeding in South Africa). Although turtles and fisheries show highly diverse distributions, we highlight nine areas of high susceptibility to potential bycatch (four in the northern Atlantic and five in the southern/equatorial Atlantic) that are worthy of further targeted investigation and mitigation. These are reinforced by reports of leatherback bycatch at eight of these sites. International collaborative efforts are needed, especially from nations hosting regions where susceptibility to bycatch is likely to be high within their exclusive economic zone (northern Atlantic: Cape Verde, Gambia, Guinea Bissau, Mauritania, Senegal, Spain, USA and Western Sahara; southern Atlantic: Angola, Brazil, Namibia and UK) and from nations fishing in these high-susceptibility areas, including those located in international waters. [ABSTRACT FROM AUTHOR]

During a monitoring programme of stranded marine mammals conducted along the north-east coast of the Rio de Janeiro State, Brazil, we collected marine tucuxi dolphins (Sotalia guianensis) stranded along the beach. We examined the carcasses to identify characteristic evidences of fishery by-catch. From July 2001 to August 2007 43 S. guianensis were found in the study area, with an annual mean of 6.1 stranding events. Dolphins stranded with evidence of fishery interaction (‘by-catch’) occurred in almost every year (annual mean = 2). The majority of the by-catch events occurred during winter and spring. Most of the stranded dolphins were sexually mature. From 43 S. guianensis stranded from 2001 to 2007, 32.5% (N = 14) of these presented evidence of by-catch. Twenty-nine other dolphins did not show clear evidence of by-catch or it could not be evaluated. Most of the by-caught dolphins occurred in the northern zones of the study area where gill-net use is intense. [ABSTRACT FROM PUBLISHER]