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Understanding how animals respond to stressors is critical for effective conservation. The present study aimed to evaluate the physiological recovery of the Shortnose Guitarfish, Zapteryx brevirostris after being incidentally captured by artisanal fleets and compared it to guitarfish with delayed mortality. Moreover, the study aimed to test the efficiency of a rehabilitation protocol for the species. To this end, individuals landed alive were transported to the rehabilitation facilities and kept in tanks under monitoring for 3 days. Physiological markers indicative of allostatic overload (i.e., lactate and phosphorus) and energy metabolism (i.e., glucose and β‐hydroxybutyrate) were assessed in the serum of the studied guitarfish: right after gillnet capture (i.e., post‐capture) and on rehabilitation (i.e., pre‐monitoring, post‐monitoring, as well as guitarfish that deceased during monitoring – post‐mortem). Results showed that the transportation and additional handling employed in the rehabilitation protocol did not increase the stress response, pointing to its potential efficacy in recovering debilitated, incidentally caught guitarfish before release. As for recovery success of monitored guitarfish, lactic acidosis was fully reverted after a 3‐day rest period, as was allostatic overload. The same was not observed in recovery failure. Correlation tests revealed key relationships between physiological markers, shedding light on how physiological pathways help guitarfish cope with capture and handling stress. This study highlights the valuable application of conservation physiology principles to fisheries management of this endemic and threatened guitarfish species. [ABSTRACT FROM AUTHOR]

Purse‐seine tropical tuna fishing in the eastern tropical Pacific Ocean (EPO) results in the bycatch of several sensitive species groups, including elasmobranchs. Effective ecosystem management balances conservation and resource use and requires considering trade‐offs and synergies. Seasonal and adaptive spatial measures can reduce fisheries impacts on nontarget species while maintaining or increasing target catches. Identifying persistently high‐risk areas in the open ocean, where dynamic environmental conditions drive changes in species' distributions, is essential for exploring the impact of fisheries closures. We used fisheries observer data collected from 1995 to 2021 to explore the spatiotemporal persistence of areas of high bycatch risk for 2 species of oceanic sharks, silky shark (Carcharhinus falciformis) and oceanic whitetip shark (Carcharhinus longimanus), and of low tuna catch rates. We analyzed data collected by fisheries scientific observers onboard approximately 200 large purse‐seine vessels operating in the EPO under 10 different flags. Fishing effort, catch, and bycatch data were aggregated spatially and temporally at 1° × 1° cells and monthly, respectively. When areas of high fishing inefficiency were closed the entire study period and effort was reallocated proportionally to reflect historical effort patterns, yearly tuna catch appeared to increase by 1–11%, whereas bycatch of silky and oceanic whitetip sharks decreased by 10–19% and 9%, respectively. Prior to fishing effort redistribution, bycatch reductions accrued to 21–41% and 14% for silky and oceanic whitetip sharks, respectively. Our results are consistent with previous findings and demonstrate the high potential for reducing elasmobranch bycatch in the EPO without compromising catch rates of target tuna species. They also highlight the need to consider new dynamic and adaptive management measures to more efficiently fulfill conservation and sustainability objectives for exploited resources in the EPO. [ABSTRACT FROM AUTHOR]

Primer registre de la petxina de pelegrí platet de Ballot Ylistrum balloti (Bernardi, 1861) al mar de la Xina meridional equatorial Ylistrum balloti és una de les espècies de Pectinidae distribuïdes a la regió de l'Indopacífic. Recentment es van registrar 15 espècimens vius d'Y. balloti a la plataforma continental de Sarawak, Malàisia. Les principals característiques morfològiques de Ylistrum balloti es localitzen a la valva exterior de color marró vermellós amb un clar patró de fines línies marrons concèntriques. A més, el destacat nombre de nervadures internes a les dues valves ajuda a identificar les espècies. L'informe preliminar d'Y. balloti va revelar que l'espècie és present a les aigües de Sarawak i que pot ser estudiada més a fons en el futur.

The main issue affecting the conservation of most pinniped species has been identified as interactions with fisheries and aquaculture. In South American waters in particular, this problem has not been well evaluated. Consequently, there is an urgent need for research and conservation measures to address the problem, particularly for species of conservation concern.In this study, we reviewed published and unpublished research and observations from the last 25 years on operational and biological interactions between pinnipeds and fisheries and salmonid aquaculture activities in South American waters, and the conservation and management implications of these interactions in the near future.Two species of pinnipeds are primarily involved in biological and operational interactions with fisheries and aquaculture in South America: the South American sea lion Otaria flavescens and the South American fur seal Arctocephalus australis. Although phocids are present in South American waters, there is no published research on conflicts between phocids and human activities.Interactions between fisheries and pinnipeds have been reported by many countries. In South American waters, interactions mostly involve male and subadult male South American sea lions. However, despite the high frequency of interactions, the estimated economic losses to fisheries and aquaculture related to sea lion depredation are generally low.Incidental capture and mortality of pinnipeds has been reported, especially in artisanal gillnet fisheries and in industrial purse seine and trawl fisheries. Mortality of sea lions in salmonid aquaculture has been reported, but the magnitude of the problem is unknown.In South America, limited progress has been made to incorporate mitigation measures, such as time‐area closures, acoustic deterrent devices, and modifications to fishing gear, into fisheries and aquaculture. This is likely to be due to our limited understanding of ecosystem complexity, the costs of modifying fishing gear or incorporating acoustic deterrent devices, and the scarcity of fishing controls. We suggest that strategies for effectively reducing conflicts between pinnipeds, fisheries, and aquaculture should involve all stakeholders in participative research to facilitate co‐management. [ABSTRACT FROM AUTHOR]

Marine megafauna is of intrinsic importance to ecosystems, but it also provides essential services for ocean health and resilience through ecological roles in the structure and dynamics of marine communities. However, bycatch by coastal fisheries has been identified as a global threat to megafauna species, compromising the persistence of threatened populations, indicating it must be systematically monitored, evaluated, and have its impacts mitigated. This study uses the DAPSI(W)R(M) framework as a tool for understanding the interactions between coastal threatened marine megafauna species and small-scale fisheries, with a focus on bycatch and activities carried out on the inner shelf of the state of Paraná, southern Brazil. The results allowed to identify research and management strategies that promote or enhance actions to reduce the impacts of bycatch, as well as well as knowledge gaps and challenges encountered, providing subsidies for the ecosystem approach and integrated management of the coastal zone of the state of Paraná.

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Após o fim da caça das baleias-francas, a interação com as atividades antrópicas, como a atividade pesqueira, é uma das principais ameaças à conservação desses animais no Sul do Brasil. De modo a identificar potenciais áreas de interação, foram realizadas entrevistas com pescadores artesanais ao longo da Área de Proteção Ambiental (APA da Baleia-Franca) identificando áreas de atividade pesqueira na unidade de conservação de uso sustentável. Utilizando estes dados, foram delimitadas as áreas de pesca através do método de estimador de densidade de kernel fixo (KDE) 95% e 50%. A partir de dados publicados de distribuição da baleia-franca, utilizando a mesma metodologia de estimação de áreas, foi analisada a sobreposição das áreas. Ao todo foram identificados 248,22 km² de áreas de interação, sendo 34,15 km² (KDE baleias 50% x KDE pesca 50%) considerados de alta interação e 214,07 km² de média interação (KDE baleias 95% x KDE pesca 50%).

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]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia 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.)

Organizaciones regionales de ordenación pesquera, organismos no gubernamentales e instancias como países con políticas y relaciones económicas comunes (por ejemplo, la Unión Europea), han realizado llamados a la industria pesquera y a los gobiernos de estados ribereños, de puerto y de pabellón, para la adopción de medidas de control y reducción de las capturas incidentales (bycatch) de megafauna asociada a las actividades pesqueras. Las capturas incidentales son un componente crítico en la evolución de las prácticas de pesca responsable. Mediante el análisis del cociente de las capturas incidentales entre las capturas objetivas se evaluó la viabilidad del enfoque espacio temporal para lograr la reducción de las capturas incidentales de tortugas marinas en la pesca de palangre de superficie. Este enfoque expone una herramienta de análisis para evaluar los cierres espacio temporales para la mejora de la pesca. Los cálculos sugieren que hacia el segundo y tercer trimestre sería posible disminuir un porcentaje acumulado del orden del 25% de la captura de tortugas marinas si se toman medidas de reducción de esfuerzo mediante una estrategia de cierre espacio temporal. Sin embargo, para definir acciones consensuadas, se requiere dar a la pesquería de palangre, un mayor seguimiento del que actualmente se les está dando.

Dolphins are among the most charismatic and peculiar organisms that inhabit marine-coastal ecosystems. Their populations have been affected in recent decades by commercial exploitation, nature tourism, poaching and the use of nonspecific fishing gear with the subsequent bycatch; being the last two, causing multiple deaths in the natural populations of these organisms. The objective of this study is to alert the scientific community and resident populations about the behavior of deaths and stranding of dolphins Tursiops truncatus in locations of the Lanzanillo-Pajonal-Fragoso Wildlife Refuge, Cuba. Cadaver samples were collected between years 2005- 2017. The dead bodies were classified according to the decomposi- tion period in fresh, decomposed, or dry bones. Data were collected about the probable cause of death and the location of the stranding. The year with the highest number of dead bodies found (four) was 2007, followed by the years 2005 and 2014, each with three bodies. The locality that reported the highest number of dead bodies was Bahía de Nazabal (eight), in accordance with the high productivity and fishing effort that it presents. A total of 15 dead bodies were found in the studied period, of these it was determined that five individuals were slaughtered for consumption, eight were acciden- tally entanglement in fishing nets and for two specimens it was not possible to determine the cause of death. The results obtained in this work contribute directly to the management and conservation of the natural populations of dolphins, as well as to the implemen- tation of programs that involve the community. RESUMEN Los delfines se encuentran entre los organismos más carismáticos y peculiares que habitan los ecosistemas marino-costeros. Sus poblaciones se han visto afectadas en las últimas décadas por la explotación comercial, el turismo de na- turaleza, la caza furtiva y el uso de artes de pesca inespecíficos que propician las capturas incidentales; siendo los dos últimos, causantes de múltiples muertes en las poblaciones natu- rales de estos organismos. El objetivo de este estudio es alertar a la comunidad científica y las poblaciones locales sobre el comportamien- to de las muertes y varamientos del delfín mu- lar Tursiops truncatus en áreas del Refugio de Vida Silvestre Lanzanillo-Pajonal-Fragoso, Cuba. Los reportes de cadáveres fueron toma- dos entre los años 2005-2017. Los cadáveres se clasificaron de acuerdo con el período de des- composición en cadáver fresco, descompues- to, y hueso seco. Se compilaron datos sobre la causa probable de muerte y la ubicación de los varamientos. El año con el mayor número de cadáveres encontrados (cuatro) fue 2007, segui- do de los años 2005 y 2014, cada uno con tres cadáveres. La localidad que reportó el mayor número de cadáveres fue Bahía de Nazabal (ocho), de acuerdo con la alta productividad y el esfuerzo de pesca que presenta. Un total de 15 cadáveres se encontraron en el período de estudio, de los cuales se determinó que cinco individuos fueron sacrificados para el consu- mo, ocho fueron atrapados accidentalmente en hamacas y para dos especímenes no fue posi- ble determinar la causa de la muerte. Los re- sultados obtenidos en este trabajo contribuyen directamente al manejo y conservación de las poblaciones naturales de delfines, así como a la implementación de programas que involu- cran a la comunidad.

Los delfines se encuentran entre los organismos más carismáticos y peculiares que habitan los ecosistemas marino-costeros. Sus poblaciones se han visto afectadas en las últimas décadas por la explotación comercial, el turismo de naturaleza, la caza furtiva y el uso de artes de pesca inespecíficos que propician las capturas incidentales; siendo los dos últimos, causantes de múltiples muertes en las poblaciones naturales de estos organismos. El objetivo de este estudio es alertar a la comunidad científica y las poblaciones locales sobre el comportamiento de las muertes y varamientos del delfín mular Tursiops truncatus en áreas del Refugio de Vida Silvestre Lanzanillo-Pajonal-Fragoso, Cuba. Los reportes de cadáveres fueron tomados entre los años 2005-2017. Los cadáveres se clasificaron de acuerdo con el período de descomposición en cadáver fresco, descompuesto, y hueso seco. Se compilaron datos sobre la causa probable de muerte y la ubicación de los varamientos. El año con el mayor número de cadáveres encontrados (cuatro) fue 2007, seguido de los años 2005 y 2014, cada uno con trescadáveres. La localidad que reportó el mayor número de cadáveres fue Bahía de Nazabal (ocho), de acuerdo con la alta productividad y el esfuerzo de pesca que presenta. Un total de 15 cadáveres se encontraron en el período de estudio, de los cuales se determinó que cinco individuos fueron sacrificados para el consumo, ocho fueron atrapados accidentalmente en hamacas y para dos especímenes no fue posible determinar la causa de la muerte. Los resultados obtenidos en este trabajo contribuyendirectamente al manejo y conservación de las poblaciones naturales de delfines, así como a la implementación de programas que involucran a la comunidad.

Copyright of Revista Biociências is the property of Revista Biociencias 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.)

Dolphins are among the most charismatic and peculiar organisms that inhabit marine-coastal ecosystems. Their populations have been affected in recent decades by commercial exploitation, nature tourism, poaching and the use of nonspecific fishing gear with the subsequent bycatch; being the last two, causing multiple deaths in the natural populations of these organisms. The objective of this study is to alert the scientific community and resident populations about the behavior of deaths and stranding of dolphins Tursiops truncatus in locations of the Lanzanillo-Pajonal-Fragoso Wildlife Refuge, Cuba. Cadaver samples were collected between years 2005-2017. The dead bodies were classified according to the decomposition period in fresh, decomposed, or dry bones. Data were collected about the probable cause of death and the location of the stranding. The year with the highest number of dead bodies found (four) was 2007, followed by the years 2005 and 2014, each with three bodies. The locality that reported the highest number of dead bodies was Bahía de Nazabal (eight), in accordance with the high productivity and fishing effort that it presents. A total of 15 dead bodies were found in the studied period, of these it was determined that five individuals were slaughtered for consumption, eight were accidentally entanglement in fishing nets and for two specimens it was not possible to determine the cause of death. The results obtained in this work contribute directly to the management and conservation of the natural populations of dolphins, as well as to the implementation of programs that involve the community. [ABSTRACT FROM AUTHOR]

The shortbill spearfish (Tetrapturus angustirostris) is a rare, large pelagic fish that inhabits the tropical and temperate waters of the Pacific and Indian Oceans, and it is seldom incidentally captured by the purse seine and longline tuna fleets. It is listed on the International Union for the Conservation of Nature red list as data deficient, with the population likely decreasing. The main objective of this paper is to contribute basic knowledge of the species catch rate, spatial distribution, temporal trends, and association with different types of fishing sets. A 23-year (1993-2015) database of incidental catches was analyzed; data was gathered by the observers from the Inter-American Tropical Tuna Commission aboard vessels from the international tuna purse seine fleet in the eastern tropical Pacific Ocean. We also analyzed time series of sea surface temperature (SST) from different Niño regions, and 2 climatic indices, the Oceanic Niño Index (ONI) and the Pacific Decadal Oscillation (PDO). The database included information from a total of 422,970 sets; of these, ~1% resulted in a catch of 687 spearfish. Most incidental catches occurred in waters close to the equator (10°S to 10°N), with no apparent seasonal distribution pattern. Time-series analyses showed a significant positive trend in incidental catch (~4% per year). Weak negative correlations of incidental catches with El Niño SST and ONI suggest that spearfish prefer cool waters in zones near the Equator. The PDO seemed to be more important to spearfish than El Niño events, and it is likely playing an important role in the positive trend of incidental catches. Most spearfish catches were associated with sets made on floating objects, mainly south of the equator and west of 100°W, highlighting the oceanic behavior of this species. [ABSTRACT FROM AUTHOR]

The aims of this study is to report some characteristics of fishing trips, effort, catches, fishing areas and bycatch through observations on board and logbooks. 85% of sets were in the first 574 Km of distance from the coast (309 nautical miles). Farthest set was located at 1320 Km (712 nautical miles). A total of 382000 hooks were used to catch Mahi mahi, in 224 sets and 29 fishing trips, 94.6% of catch was Mahi mahi, 2.7% blue shark (Prionace glauca) y 1,3% mako shark (Isurus oxyrinchus). Also, 103790 hooks were used to catch sharks, in 109 sets y 12 trips, 81.9% of catch was blue sharks and 16.8% mako sharks. Catch per Unit of Effort (CPUE) for Mahi mahi shows significative difference among seasons; with a peak from November to January. CPUE for shark shows significative difference among seasons, with peaks in September and October. The Green turtle Chelonia mydas agassizii was the most caugth species and two of three were juveniles. All Loggerhead turtles, Caretta caretta, caught were juveniles. A petrel is reported as bycatch and, probably, mammal bycatch is scarce. Considering the huge effort of this fishery, it is important to monitor it and establish management actions.

An inventory of 24 fish species incidentally caught by the Patagonian scallop fleet in the SW Atlantic Ocean is provided for the first time. The most frequent species were Psammobatis spp. (81.4%), Bathyraja brachyurops (75.1%), B. macloviana (73.5%), Patagonotothen ramsayi (66.1%), Merluccius hubbsi (53.7%) and B. albomaculata (50.3%). Many of the recorded chondrichthyes are considered vulnerable or endangered species. The number of taxa (fishes + invertebrates) that conforms the by-catch of the fishery was increased and updated to nearly 200 species.Este estudio presenta por primera vez un inventario con 24 especies de peces registradas en la captura incidental de la pesca de la vieira patagónica en el Océano Atlántico sudoccidental por la flota pesquera comercial. Las especies más frecuentes fueron Psammobatis spp. (81,4%), Bathyraja brachyurops (75,1%), B. macloviana (73,5%), Patagonotothen ramsayi (66,1%), Merluccius hubbsi (53,7%) y B. albomaculata (50,3%). Muchos de los condrictios registrados se encuentran actualmente considerados como especies vulnerables o en peligro. El número de taxa (peces + invertebrados) que conforman la captura incidental de esta pesquería se incrementó y actualizó con estos resultados a aproximadamente 200 especies.

Se presenta evidencia del aumento de capturas incidentales de tortugas marinas en el norte del Perú, durante el fenómeno El Niño Oscilación del Sur (ENOS) 1997-1998. El área de estudio se ubica frente a Lambayeque, entre 6°20'S y 7°10'S, y desde la costa hasta 35 mn mar afuera. Se analizaron y describieron los aparejos de enmalle por ser los que más interactuaban con estas tortugas, así como las características de las embarcaciones. Se registraron las tortugas capturadas por la flota artesanal entre enero 1996 y diciembre 1998; se identificó las especies capturadas y se analizó la captura por unidad de esfuerzo (CPUE); la información se correlacionó con la temperatura superficial del mar (TSM). Se analizó un total de 265 operaciones de pesca, capturándose un total de 383 tortugas, correspondiendo 80,4% a la tortuga pico de loro (Lepidochelys olivacea), 19,3% a la tortuga verde (Chelonia mydas) y 0.2% a la tortuga carey (Eretmochelys imbricata). Se encontró una correlación altamente significativa entre las capturas de tortugas marinas y la TSM con un intervalo de confianza del 99% (Pearson; r = 0,787; σ = 0,000; N = 36). Se recomienda reforzar la colaboración entre entidades públicas y privadas para implementar medidas de manejo adecuadas para la conservación de estas especies amenazadas, sobre todo ante la eventualidad de un fenómeno ENOS.The main purpose of this work is to present evidence of sea turtles by-catch increase in northern Peru during the 1997-1998 El Niño Southern Oscillation (ENSO) process. The study area is located off Lambayeque, between 6°20'S and 7°10'S, and from the coastline up to 35 nm offshore. The gillnet artisanal fishery was analyzed and described, since this was the fishing gear which most interact with sea turtles, the boat characteristics were evaluated as well. Sea turtle captures and species identification were registered from January 1996 until December 1998. The catch per unit effort (CPUE) was analyzed. Data was correlated with sea surface temperature (SST). A total of 265 fishing operations were analyzed, from which a total of 383 sea turtles were captured: being 80.4% olive ridleys (Lepidochelys olivacea); 19.3% green turtles (Chelonia mydas) and 0.2% hawksbill turtles (Eretmochelys imbricata). A positive significant correlation with a 99% confidence interval was found between sea turtle captures and SST (Pearson; r = 0.787; σ = 0.000; N = 36). We recommend strengthening collaboration between public and private organizations, to implement appropriate management measures for the conservation of sea turtles, especially during an ENSO event.

Se analizó la relación entre la variabilidad de la tasa de captura incidental de aves marinas en la pesquería palangrera pelágica de pez espada (Xiphias gladius) y diversos factores temporales, ambientales, espaciales y pesqueros, entre 2007 y 2009. Los resultados muestran que las operaciones de pesca de esta flota afectan principalmente a los albatros, grupo que concentra el 83,7% de la captura incidental de aves marinas registrada en el período. Esta captura incidental se debe en primera instancia a la presencia del Frente Subtropical del Pacífico Sur, sistema que provoca la sobreposición entre la actividad de esta flota con la distribución espacial de aves marinas durante la fase residente del período no reproductivo. La variabilidad en esta captura incidental estaría fuertemente relacionada a los estímulos visuales (medido mediante el porcentaje de luces químicas y porcentaje de calamar) y las condiciones de luminosidad ambiental existentes en los períodos de forrajeo diurno y nocturno de estas aves marinas durante el calado (medido a través del desfase de la hora del ocaso con respecto a la hora de inicio del calado y fase lunar).We analized the relationship between the variability in the rate of seabird bycatch in pelagic longline fishery for swordfish (Xiphias gladius), and several temporary, environmental, spatial and fisheries factors for the fishing period from 2007 to 2009. The results show that the fishing operations of this fleet mainly affect the albatross, group that accounts for 83.7% of the incidental catch of seabirds recorded in the period. This bycatch is due primarily to the presence of the South Pacific Subtropical Front, a system that causes the overlap between the activities of this fleet with the spatial distribution of these seabird species during the resident phase of the nonbreeding period. By the other hand, the variability in bycatch would be strongly linked to visual stimuli (measured by the percentage of chemical lights and percentage of squid) and the existing ambient lighting conditions during the set (measured by the lag time of sunset with respect to time start set and lunar phase).

A pesca é de grande importância para o desenvolvimento socioeconômico das comunidades ribeirinhas amazônicas, as quais possuem um conhecimento local do ambiente, sua fauna e flora. Esse conhecimento é de grande importância para manejo e conservação dos estoques pesqueiros e das espécies que interagem com a atividade de pesca, como as populações de botos-cinza (Sotalia sp.) e botos-rosa (Inia geoffrensis). Portanto, para registrar o conhecimento ecológico local e a interação de botos com a pesca no litoral do estado do Pará, foram realizadas 82 entrevistas semiestruturadas em três diferentes colônias de pescadores: colônia Z-1 (Soure), colônia Z-7 (Maracanã) e colônia Z-23 (Colares). A espécie Sotalia sp. apresentou forte estrutura social, podendo ser observado na região tanto no período seco quanto no chuvoso, enquanto a espécie I. geoffrensis não apresentou uma estruturação social, sendo observada na região preferencialmente no período chuvoso. O boto-rosa demonstrou maior interação com a pesca do que o boto-cinza, no entanto, essa interação foi principalmente prejudicial à atividade, enquanto o boto-cinza demonstrou tanto uma interação prejudicial quanto benéfica à pesca. A captura acidental dos botos ocorreu principalmente por meio de redes e espinheis, prejudicando suas populações. Os animais capturados foram, em sua maioria, soltos, entretanto, houve registro do consumo na alimentação, utilização como isca e comercialização dos olhos do animal. Essas informações servirão de base para estudos futuros sobre a biologia, ecologia e estimativa da mortalidade de botos no litoral amazônico. Medidas de manejo devem ser adotadas, juntamente com as comunidades estudadas, para a conservação desses animais na região.

Reduction of the by-catch in shrimp fishery is an important goal worldwide. In order to compare by-catch using the conventional trawling net and a newly designed short funnel net, nine cruises were carried out by the commercial fleet operating in the Gulf of Tehuantepec, Mexico. A total of 480 trawls were done (mean duration: 85 min). The experimental trawls using the modified net produced a 21.13-28.86 % by-catch reduction (confidence interval 95 %), a 3 % increase of shrimp catch, and a significant reduction on net recovery time. Rev. Biol. Trop. 55 (3-4): 889-897. Epub 2007 December, 28.La reducción de la fauna de acompañamiento del camarón (FAC) es uno de los temas de discusión más importantes en la pesca mundial. Con la finalidad de contribuir en este tópico, se diseñó y utilizó una red de arrastre variando la longitud del túnel, y se comparó su efecto con el de una red tradicional; durante 9 cruceros de la flota comercial en el Golfo de Tehuantepec, México. Se realizó un total de 480 lances con promedio de 85 min cada uno. Los arrastres de la red modificada mostraron mejores resultados, con variación entre 21.13 a 28.86 %, con un 95 % de confianza de reducción de FAC, un incremento de 3 % en la captura de camarón, y una disminución del tiempo de recuperación, lo que sugiere un incremento en la eficiencia gracias al nuevo diseño.

The use of the turtle excluder device (TED) has been mandatory in Brazil since 1994. In spite of the importance of sea turtle bycatch reduction, TED effectiveness to maintain target species capture had never been evaluated in shrimp fisheries off southern Brazil. For this purpose, a test was carried out in November 2013 with the TED installed with two different configurations, top or bottom opening under the supervision of a technician of the National Oceanic and Atmospheric Administration (NOAA). Absolute catch and fishery yields were simultaneously monitored in 10 fishing hauls of a double-rig trawler by an onboard observer in one net equipped with a TED and the other without a TED. Although a Bayesian hypothesis test demonstrated no significant differences through the simultaneous comparison of absolute capture considering the use and non-use of the TED, the credibility interval of posterior beta distributions intercepted almost its minimum limit which weakens the hypothesis of equality. In terms of orientation, the model mounted with the top opening showed no differences in absolute catches of the target species in respect to control. [ABSTRACT FROM AUTHOR]

An important ark clam (Arca zebra) artisanal fishery takes place in the east region of Venezuela. Besides the target species, trawling extracts a significant bycatch of several mollusk species including the gastropod Voluta musica, a threatened species according to the Venezuelan Red List of Endangered Species. In this paper we evaluate: 1) the composition of mollusk species in the bycatch, 2) the number of individuals of V. musica caught as bycatch and, 3) the abundance and size structure of the exploited population. Each fishing night, about 27,830 m² are trawled by each boat extracting on the average 607 kg of A. zebra meat and 19 kg of V. musica (whole shelled animal). This fishery activity potentially captures ~30,000 kg of ark clam meat and 922 kg of V. musica in one week (~95 snails/fishing night/boat). The size structure of the V. musica population at the ark clam bed is significantly smaller than in other nearby sites not impacted by trawling fishing activities. Non-targeted species extracted in the bycatch but consumed by the local inhabitants include the gastropods Chicoreus brevifrons, Phyllonotus margaritensis, P. pomum, Fasciolaria tulipa, Strombus pugilis, a few Trochidae species, and the bivalves Pinctada imbricata, Spondylus americanus, Anadara floridana, A. notabilis, and Trachicardium muricatum. Individuals of V. musica along with several invertebrates are discarded. We recommend that V. musica should not be neglected as a conservation target, and despite that A. zebra fisheries are considered "artisanal", that more strict regulations should be established on it. [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.

Atlantic sturgeon (Acipenser oxyrhynchus) populations have been declared either endangered or threatened under the U.S. Endangered Species Act. Effective measures to repel sturgeon from fishing gear would be beneficial to both fish and fishers because they could reduce both fishery-associated mortality and the need for seasonal and area closures of specific fisheries. Some chondrostean fishes (e.g., sturgeons and paddlefishes) can detect weak electric field gradients (possibly as low as 5 Μv/cm) due to arrays of electroreceptors (ampullae of Lorenzini) on their snout and gill covers. Weak electric fields, such as those produced by electropositive metals (typically mixtures of the lanthanide elements), could therefore potentially be used as a deterrent. To test this idea, we recorded the behavioral responses of juvenile Atlantic sturgeon (31-43 cm fork length) to electropositive metal (primarily a mixture of the lanthanide elements neodymium and praseodymium) both in the presence and absence of food stimuli. Trials were conducted in an approximately 2.5 m diameter × 0.3 m deep tank, and fish behaviors were recorded with an overhead digital video camera. Video records were subsequently digitized (x, y coordinate system), the distance between the fish and the electropositive metal calculated, and data summarized by compiling frequency distributions with 5-cm bins. Juvenile sturgeon showed clear avoidance of electropositive metal but only when food was present. On the basis of our results, we conclude that the electropositive metals, or other sources of weak electric fields, may eventually be used to reduce the interactions of Atlantic sturgeon with fishing gear, but further investigation is needed. El Potencial del Metal Electropositivo para Reducir las Interacciones del Esturión Atlántico con Instrumentos de Pesca Bouyoucos, Bushnell & Brill 13-003 [ABSTRACT FROM AUTHOR]

Although holistic conservation addressing all sources of mortality for endangered species or stocks is the preferred conservation strategy, limited budgets require a criterion to prioritize conservation investments. We compared the cost-effectiveness of nesting site and at-sea conservation strategies for Pacific leatherback turtles ( Dermochelys coriacea). We sought to determine which conservation strategy or mix of strategies would produce the largest increase in population growth rate per dollar. Alternative strategies included protection of nesters and their eggs at nesting beaches in Indonesia, gear changes, effort restrictions, and caps on turtle takes in the Hawaiian (U.S.A.) longline swordfish fishery, and temporal and area closures in the California (U.S.A.) drift gill net fishery. We used a population model with a biological metric to measure the effects of conservation alternatives. We normalized all effects by cost to prioritize those strategies with the greatest biological effect relative to its economic cost. We used Monte Carlo simulation to address uncertainty in the main variables and to calculate probability distributions for cost-effectiveness measures. Nesting beach protection was the most cost-effective means of achieving increases in leatherback populations. This result creates the possibility of noncompensatory bycatch mitigation, where high-bycatch fisheries invest in protecting nesting beaches. An example of this practice is U.S. processors of longline tuna and California drift gill net fishers that tax themselves to finance low-cost nesting site protection. Under certain conditions, fisheries interventions, such as technologies that reduce leatherback bycatch without substantially decreasing target species catch, can be cost-effective. Reducing bycatch in coastal areas where bycatch is high, particularly adjacent to nesting beaches, may be cost-effective, particularly, if fisheries in the area are small and of little commercial value. Rentabilidad de Estrategias de Conservación Alternativas Aplicadas a Tortugas Laúd del Pacífico [ABSTRACT FROM AUTHOR]

An inventory of 24 fish species incidentally caught by the Patagonian scallop fleet in the SW Atlantic Ocean is provided for the first time. The most frequent species were Psammobatis spp. (81.4%), Bathyraja brachyurops (75.1%), B. macloviana (73.5%), Patagonotothen ramsayi (66.1%), Merluccius hubbsi (53.7%) and B. albomaculata (50.3%). Many of the recorded chondrichthyes are considered vulnerable or endangered species. The number of taxa (fishes + invertebrates) that conforms the by-catch of the fishery was increased and updated to nearly 200 species. [ABSTRACT FROM AUTHOR]

The main purpose of this work is to present evidence of sea turtles by-catch increase in northern Peru during the 1997-1998 El Niño Southern Oscillation (ENSO) process. The study area is located off Lambayeque, between 6°20'S and 7°10'S, and from the coastline up to 35 nm offshore. The gill-net artisanal fishery was analyzed and described, since this was the fishing gear which most interact with sea turtles, the boat characteristics were evaluated as well. Sea turtle captures and species identification were registered from January 1996 until December 1998. The catch per unit effort (CPUE) was analyzed. Data was correlated with sea surface temperature (SST). A total of 265 fishing operations were analyzed, from which a total of 383 sea turtles were captured: being 80.4% olive ridleys (Lepidochelys olivacea); 19.3% green turtles (Chelonia mydas) and 0.2% hawksbill turtles (Eretmochelys imbricata). A positive significant correlation with a 99% confidence interval was found between sea turtle captures and SST (Pearson; r = 0.787; σ = 0.000; N = 36). We recommend strengthening collaboration between public and private organizations, to implement appropriate management measures for the conservation of sea turtles, especially during an ENSO event. [ABSTRACT FROM AUTHOR]

We analized the relationship between the variability in the rate of seabird bycatch in pelagic longline fishery for swordfish (Xiphias gladius), and several temporary, environmental, spatial and fisheries factors for the fishing period from 2007 to 2009. The results show that the fishing operations of this fleet mainly affect the albatross, group that accounts for 83.7% of the incidental catch of seabirds recorded in the period. This bycatch is due primarily to the presence of the South Pacific Subtropical Front, a system that causes the overlap between the activities of this fleet with the spatial distribution of these seabird species during the resident phase of the nonbreeding period. By the other hand, the variability in bycatch would be strongly linked to visual stimuli (measured by the percentage of chemical lights and percentage of squid) and the existing ambient lighting conditions during the set (measured by the lag time of sunset with respect to time start set and lunar phase). [ABSTRACT FROM AUTHOR]

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Bycatch--the incidental catch of nontarget species--is a principal concern in marine conservation and fisheries management. In the eastern Pacific Ocean tuna fishery, a large fraction of nonmammal bycatch is captured by purse-seine gear when nets are deployed around floating objects. We examined the spatial distribution of a dominant species in this fishery's bycatch, the apex predator silky shark (Carcharhinus falciformis ), from 1994 to 2005 to determine whether spatial closures, areas where fishing is prohibited, might effectively reduce the bycatch of this species. We then identified candidate locations for fishery closures that specifically considered the trade-off between bycatch reduction and the loss of tuna catch and evaluated ancillary conservation benefits to less commonly captured taxa. Smoothed spatial distributions of silky shark bycatch did not indicate persistent small areas of especially high bycatch for any size class of shark over the 12-year period. Nevertheless, bycatch of small silky sharks (<90 cm total length) was consistently higher north of the equator during all years. On the basis of this distribution, we evaluated nearly 100 candidate closure areas between 5°N and 15°N that could have reduced, by as much as 33%, the total silky shark bycatch while compromising only 12% of the tuna catch. Although silky sharks are the predominant species of elasmobranchs caught as bycatch in this fishery, closures also suggested reductions in the bycatch of other vulnerable taxa, including other shark species and turtles. Our technique provides an effective method with which to balance the costs and benefits of conservation in fisheries management. Spatial closures are a viable management tool, but implementation should be preceded by careful consideration of the consequences of fishing reallocation. [ABSTRACT FROM AUTHOR]

Commercial and subsistence fisheries pressure is increasing in the Gulf of California, Mexico. One consequence often associated with high levels of fishing pressure is an increase in bycatch of marine mammals and birds. Fisheries bycatch has contributed to declines in several pinniped species and may be affecting the California sea lion (Zalophus californianus ) population in the Gulf of California. We used data on fisheries and sea lion entanglement in gill nets to estimate current fishing pressure and fishing rates under which viable sea lion populations could be sustained at 11 breeding sites in the Gulf of California. We used 3 models to estimate sustainable bycatch rates: a simple population-growth model, a demographic model, and an estimate of the potential biological removal. All models were based on life history and census data collected for sea lions in the Gulf of California. We estimated the current level of fishing pressure and the acceptable level of fishing required to maintain viable sea lion populations as the number of fishing days (1 fisher/boat setting and retrieving 1 day's worth of nets) per year. Estimates of current fishing pressure ranged from 101 (0–405) fishing days around the Los Machos breeding site to 1887 (842–3140) around the Los Islotes rookery. To maintain viable sea lion populations at each site, the current level of fishing permissible could be augmented at some sites and should be reduced at other sites. For example, the area around San Esteban could support up to 1428 (935–2337) additional fishing days, whereas fishing around Lobos should be reduced by at least 165 days (107–268). Our results provide conservation practitioners with site-specific guidelines for maintaining sustainable sea lion populations and provide a method to estimate fishing pressure and sustainable bycatch rates that could be used for other marine mammals and birds. [ABSTRACT FROM AUTHOR]

A multicriteria assessment of fishing zones was carried out using the utility function (U) technique, considering three management objectives (maximizing tuna yield, minimizing dolphin mortality, and minimizing bycatch) and seven different weights among them. The Mexican purse-seine tuna fishery in the eastern Pacific Ocean was used as case study, based on data obtained between 1998 and 2003 by the Mexican Tuna-Dolphin Program. The fishing zones were classified by trimester according to U, and 64% were identified as conflictive (U > 0.666 for some weights, but U < 0.333 for others); hence, two of every three trimestral quadrants require negotiation among the decision makers given the complex nature of the fishery. Quadrants with specific characteristics were identified in cases where, for instance, some particular sets explained the high bycatch values, or the targeting of bluefin tuna explained their classification as excellent. Even though the weights used provided a good proxy, in view of the great variability in space and time of the pelagic resources, actual preferences (weights) should be differentiated in space and time in order to be useful in the decision-making process. Particularly noteworthy is that well-structured and efficient management schemes have already been implemented for two of the objectives (maximizing tuna yield and minimizing dolphin mortality), but not for the third (minimizing bycatch). [ABSTRACT FROM AUTHOR]

Fishers, scientists, and resource managers have made substantial progress in reducing bycatch of sea turtles, seabirds, and marine mammals through physical modifications to fishing gear. Many bycatch-avoidance measures have been developed and tested successfully in controlled experiments, which have led to regulated implementation of modified or new fishing gear. Nevertheless, successful bycatch experiments may not translate to effective mitigation in commercial fisheries because experimental conditions are relaxed in commercial fishing operations. Such a difference between experimental results and real-world results with fishing fleets may have serious consequences for management and conservation of protected species taken as bycatch. We evaluated preimplementation experimental measures and postimplementation efficacy from primary and gray literature for three case studies: acoustic pingers that warn marine mammals of the presence of gill nets, turtle excluder devices that reduce bycatch of turtles in trawls, and various measures to reduce seabird bycatch in longlines. Three common themes to successful implementation of bycatch reduction measures are long-standing collaborations among the fishing industry, scientists, and resource managers; pre- and postimplementation monitoring; and compliance via enforcement and incentives. [ABSTRACT FROM AUTHOR]

Reduction of the by-catch in shrimp fishery is an important goal worldwide. In order to compare bycatch using the conventional trawling net and a newly designed short funnel net, nine cruises were carried out by the commercial fleet operating in the Gulf of Tehuantepec, Mexico. A total of 480 trawls were done (mean duration: 85 min). The experimental trawls using the modified net produced a 21.13-28.86 % by-catch reduction (confidence interval 95 %), a 3 % increase of shrimp catch, and a significant reduction on net recovery time. [ABSTRACT FROM AUTHOR]

Marine biological hotspots, or areas where high abundances of species overlap in space and time, are ecologically important areas because energy flow through marine food webs, a key ecosystem process, is maximized in these areas. I investigated whether top predators aggregated at persistent spawning sites of a key forage fish species, capelin (Mallotus villosus), on the NE coast of Newfoundland during July and August 2000–2003. By examining the distributional patterns of top predators through ship-based surveys at multiple spatial and temporal scales, I found that the biomasses of birds—dominated by Common Murres (Uria aalge) —and mammals—dominated by whale species—were concentrated along the coast, with a biological hotspot forming near two persistent spawning sites of capelin in all years. The formation of this hotspot was well defined in space and time from middle of July to middle of August, likely coinciding with the spawning chronology of capelin. Within this hotspot, there was a high spatial and temporal overlap of Common Murres and gill nets set to capture Atlantic cod (Gadus morhua). This resulted in breeding murres becoming entangled in gill nets while feeding on spawning capelin. Despite an acknowledged uncertainty of bycatch mortality, estimates for the larger regional-scale area (1936–4973 murres/year; 0.2–0.6% of the breeding population) underestimated mortality relative to estimates within the hotspot (3053–14054 murres/year; 0.4–1.7%). Although fishing effort for Atlantic cod has declined substantially since the groundfish moratorium in 1992, chronic, unnatural, and additive mortality through bycatch continues in coastal Newfoundland. Restricted use of gill nets within this and other biological hotspots during the capelin spawning period appears to be a straightforward application of the “ecological and biologically significant area” management framework in Canada's Oceans Act. This protection would minimize murre bycatch and maintain ecosystem integrity. [ABSTRACT FROM AUTHOR]

The piked dogfish Squalus acanthias is part of the bycatch of several South American longline fisheries, although in Argentina, it was only reported in the bycatch of benthic and demersal fisheries operating bottom nets. This communication represents the first record of S. acanthias bycatch in a commercial semi-pelagic longline fishery within Argentinean waters. In October-November 2005, 185 piked dogfish were captured (122 females and 63 males). The estimated mean catch rate was 0.37 sharks/1000 hooks (544,320 hooks deployed). Nearly hall of the captured females and over 50% of captured males were morphometrically mature. The piked dogfish bycatch could bave been influenced by the use of the Argentine shortfin squid Illex argentinus as bait; this squid is part of the shark's natural diet. Although S. acanthias is abundant in the region, we believe that the bycatch species could be more vulnerable than the targeted ones since the signs indicating a declining population of non-target species in commercial catches and collapses in bycatch populations go unnoticed. [ABSTRACT FROM AUTHOR]