Abstract (Introduction): Bycatch and discards are a socio-environmental concern that threatens the sustainability of marine life and fishing grounds. Approaches to this problem have focused on biological and/or ecological aspects. We considered it necessary to explore the problem from the social dimension and for this purpose we explored social representations. (Objective): The aim of this study is to explore the social representations of bycatch and discards in a group of businessmen and workers in the capture stage of the Argentine industrial fishing activity. We ask how they evaluate bycatch and fishing discards, what are their causes and if they observe possible solutions. (Methodology): Within the framework of a project of the Federal Fishing Council, we conducted focus groups with businessmen, business chambers, SOMU workers and captains of the industrial fishing activity. (Results): The results of the focus groups conducted in 2021 reveal three main causes of this problem. First, the lack of reliable data on actual discard levels raises concerns about sustainability and overfishing. Second, the low utilization of selectivity devices is attributed to their operational inefficiency and possible labour barriers. Finally, economic and organizational pressures, such as company profitability and workers’ salaries, justify the discard of non-target species, exacerbating the problem. (Conclusions): The work contributes to an understanding of the main reasons for bycatch and discards, which is essential to advance solutions. We understand that solutions are not simple and involve a sincere debate among stakeholders.

Resumen (Introducción): Las capturas incidentales y los descartes pesqueros son una preocupación socioambiental que amenaza la sostenibilidad de la vida marina y de los caladeros. Los abordajes a esta problemática estuvieron centrados en aspectos biológicos y ecológicos. Consideramos necesario explorar la problemática desde la dimensión social y para ello, exploramos las representaciones sociales. (Objetivo): El objetivo de este estudio fue explorar las representaciones sobre capturas incidentales y descartes pesqueros en un grupo de empresarios y trabajadores de la etapa de captura de la actividad pesquera industrial argentina, específicamente, cómo evalúan este problema, sus causas y posibles soluciones. (Metodología): En el marco de un proyecto del Consejo Federal Pesquero, se realizaron grupos focales con seis cámaras empresariales y personal jerárquico de empresas asociadas, así como trabajadores del SOMU y capitanes que operan en alta mar. (Resultados): Los resultados de los grupos focales realizados en 2021 revelaron tres principales causas de dicha problemática. Primero, la falta de datos confiables sobre los niveles reales de descarte genera preocupaciones sobre la sostenibilidad y la sobreexplotación. Segundo, la escasa utilización de dispositivos de selectividad se atribuye a su ineficacia operativa y a posibles barreras laborales. Finalmente, las presiones económicas y organizacionales, como la rentabilidad de las empresas y los salarios de los trabajadores, justifican el descarte, exacerbando el problema. (Conclusiones): El trabajo aporta a un entendimiento sobre las razones de la captura incidental y los descarte, esencial para avanzar en soluciones. Entendemos que las soluciones no son simples e implican un sincero debate entre actores.

ABSTRACT Overfishing, industrial fishing and climate change generate impacts that affect the marine fishery resource, the main source of income and food for coastal populations of artisanal fishers. The creation of conditions that increase the adaptive capacity of fishers will decrease their vulnerability to impacts. This research proposes to determine an Exclusive Zone for Artisanal Fishing-ZEPA as a strategy for sustainable management of fishery resources and climate adaptation for artisanal fishers in the study area. Marxan was used to identify three scenarios for the location of the ZEPA and participatory mapping was carried out with fishers to obtain the fourth scenario. High similarity was found between scenarios 2 and 4, which shows that the scientific (Marxan) and participatory (population) approaches coincide in the location of the ZEPA. The final ZEPA was located in the coastal marine zone of the municipalities of Tumaco and Francisco Pizarro, with a total area of 2,008 km2. Included important conservation targets for artisanal fisheries such as artisanal fishing grounds, ecosystems (mangroves, beaches and estuaries), areas of occurrence of species (seerfish, snappers, sea bass, piangua, marmoset shrimp) among others. More than 80 % of the fishers agreed that the strategy would help reduce their vulnerability to threats such as climatic phenomena, overfishing, pollution, among others. The contribution to climate change adaptation of the study area’s population is highlighted.

RESUMEN La sobrepesca, la pesca industrial y el cambio climático generan impactos que afectan al recurso pesquero marino, la principal fuente de ingreso y alimento de las poblaciones costeras de pescadores artesanales. La creación de condiciones que incrementen la capacidad de adaptación de los pescadores disminuirá su vulnerabilidad a los impactos. Esta investigación propone determinar una Zona Exclusiva de Pesca Artesanal-ZEPA como estrategia de manejo sostenible de los recursos pesqueros y de adaptación climática para los pescadores artesanales del área de estudio. Se utilizó el programa Marxan para identificar tres escenarios para la ubicación de la ZEPA y se realizó una cartografía participativa con pescadores para obtener el cuarto escenario. Se encontró similitud alta entre el escenario 2 y 4, lo que muestra que el enfoque científico (Marxan) y participativo (población) coinciden en la ubicación de ZEPA. La ZEPA definitiva se ubicó en la zona marino costera de los municipios de Tumaco y Francisco Pizarro, con un área total de 2 008 km2. Incluyó objetos de conservación importantes para la pesca artesanal como caladeros de pesca artesanal, ecosistemas (manglares, playas y estuarios), áreas de ocurrencia de especies (sierra, pargos, corvina, piangua, camarón tití), entre otros. Se identificó que más de 80 % de los pescadores estuvo de acuerdo en que la estrategia le aportaría a reducir su vulnerabilidad frente a amenazas como fenómenos climáticos, sobrepesca, contaminación, entre otros. Se resalta la contribución a la adaptación al cambio climático de la población del área de estudio.

ABSTRACT. A commercial fishery for the smooth hammerhead shark (Sphyrna zygaena) exists in the waters off northern Peru. Although international and domestic norms regulate this species, adult specimens are becoming rare. Monthly visits to four ports in the La Libertad region were made to measure S. zygaena landings and understand the present state of the fishery. We found that 92% of the specimens landed were juveniles or younger and that 10% of the original biomass remains in the fishery. This highlights that stricter regulations such as protecting breeding areas, establishing a legal catch length, and limiting the catch volume and fishing season are urgently needed to maintain a sustainable fishery.

Resumo Se desarrolló una investigación para caracterizar la percepción social de las principales amenazas que podrían afectar un ambiente acuático particular- una laguna costera- mediante la aplicación de una versión del método denominado mapeo participativo de riesgos, más sencillo que el método del paradigma psicométrico tradicionalmente utilizado. Consiste en entrevistas en las que el interrogado comenta sobre los principales problemas o amenazas ambientales que percibe y los jerarquiza según tres criterios: gravedad, urgencia y control. De cada categoría de amenaza identificada se obtuvo el índice de incidencia- la fracción de entrevistados que citaron la categoría problema - y los índices de gravedad, urgencia y control. Con estos índices se elaboran mapas gráficos de percepción de las amenazas según cada criterio. El método se aplicó a un grupo de pescadores que hacen uso de la laguna, los cuales perciben cinco (5) problemas ambientales: el desvío de ríos, la obstrucción de ríos y el cierre temporal de la boca de conexión de la laguna con el mar (casos particulares de la hidrodinámica alterada), el crecimiento excesivo del mangle y la pesca de peces juveniles; estos dos últimos son percibidos como los de mayor facilidad en controlar. Se demuestran las bondades del método.

Abstract A research was developed to characterize the social perception of threats that could affect a particular aquatic environment - a coastal lagoon - by applying a version of the method called participatory risk mapping, simpler than the traditionally used psychometric paradigm method. It consists of interviews in which the interrogated comments on the main environmental problems or threats that he perceives and rank them according to three criteria: severity, urgency and control. For each identified threat category, the incidence rate - the fraction of respondents who cited the problem category - and the indices of severity, urgency and control were obtained. With these indices, graphic maps of threat perception are elaborated according to each criterion. The method was applied to a group of fishermen who make use of the lagoon, who perceive five (5) environmental problems: rivers diversion, rivers obstruction and the temporary closure of lagoon connection with the sea (cases of altered hydrodynamics), the excessive growth of the mangrove and overfishing of juvenile fish; the latter two are perceived as the easiest to control. The benefits of the method are demonstrated.

Abstract The Atlantic goliath grouper Epinephelus itajara is the largest grouper species in the Atlantic Ocean. Despite the conservation status being Vulnerable (VU) globally and Critically Endangered (CR) in Brazil, the species continues to face threats from overfishing throughout its range. We used DNA barcoding employing the mitochondrial Cytochrome c oxidase subunit I (COI) gene to identify the illegal commercialization of E. itajara in fish markets from the northern (NC) and southern (SC) Brazilian coasts. Sampling was conducted in fish markets and aimed to confirm the identification of mischaracterized fish sold as E. itajara in the NC, as well as identifying fish fillets sold as the Dusky grouper in the SC. DNA barcoding allowed the unambiguous identification of 22 (84.6%) of the 26 analyzed fish market samples. Both sampled areas had confirmation of E. itajara illegal commercialization and from the 22 analyzed samples, 17 (77.3%) were confirmed to be E. itajara. Here we report two crimes, the illegal sale of E. itajara and commercial fraud by species substitution. This study has highlighted that the existing legislation that protects E. itajara in Brazilian waters requires the adoption of better public policies for the conservation of the species. Ocean VU (VU CR (CR Brazil range COI (COI E NC (NC SC (SC coasts 2 84.6% 846 84 6 (84.6% samples 1 77.3% 773 77 3 (77.3% crimes substitution 84.6 8 (84.6 77.3 7 (77.3 84. (84. 77. (77. (84 (77 (8 (7 (

Resumo O mero do Atlântico Epinephelus itajara é a maior espécie de garoupa no Oceano Atlântico. Apesar do seu status de conservação Vulnerável (VU) globalmente e Criticamente em Perigo (CR) no Brasil, a espécie continua enfrentando ameaças da sobrepesca em toda a sua área de distribuição. Utilizamos o sequenciamento de DNA por código de barras, empregando o gene mitocondrial da Citocromo c oxidase subunidade I (COI), para identificar a comercialização ilegal de E. itajara em mercados de peixe nas costas norte (CN) e sul (CS) do Brasil. A coleta de amostras foi realizada em mercados de peixe e teve como objetivo confirmar a identificação de peixes descaracterizados e vendidos como E. itajara na CN, bem como identificar filés de peixe vendidos como garoupa verdadeira na CS. O sequenciamento de DNA por código de barras permitiu a identificação inequívoca de 22 (84,6%) das 26 amostras de mercado de peixe analisadas. Ambas as áreas amostradas tiveram confirmação da comercialização ilegal de E. itajara, e das 22 amostras analisadas, 17 (77,3%) foram confirmadas como E. itajara. Nós relatamos aqui dois crimes, a venda ilegal de E. itajara e a fraude comercial por substituição de espécies. Este estudo ressaltou que a legislação existente que protege E. itajara em águas brasileiras requer a adoção de melhores políticas públicas para a conservação da espécie. VU (VU CR (CR Brasil distribuição COI, COI , (COI) E CN (CN CS (CS 2 84,6% 846 84 6 (84,6% analisadas 1 77,3% 773 77 3 (77,3% crimes espécies (COI 84,6 8 (84,6 77,3 7 (77,3 84, (84, 77, (77, (84 (77 (8 (7 (

Abstract Narcine entemedorandRhinoptera steindachneriare 2 viviparous batoid species of commercial importance on the Pacific coast of Mexico. However, no adequate management plan has been set forth for either of them to ensure sustainable use. The aims of this study were to assess the reproductive potential and the potential rate of population increase (rʹ) of both species, as well as contrasting their reproductive strategies, to infer how susceptible they are to fishing exploitation. Comparatively, among batoids,N. entemedorfemales have an early age at maturity, relatively high fecundity, and an intermediate lifespan, whileR. steindachnerifemales have an early age at maturity, low fecundity, and a relatively short lifespan. According to our estimates, however, both species have relatively high reproductive potential, whichN. entemedorexhibits by investing energy in maximizing fecundity andR. steindachneriby increasing the embryo’s body mass. Therefore,N. entemedorhas better capacity to recover from relatively high overfishing (rʹ = 0.48) in comparison withR. steindachneri(rʹ = -0.18). The methodology used in this study proved to be a good option to assess the risk of overfishing in species for which there is limited data.

Resumen Narcine entemedoryRhinoptera steindachnerison 2 especies de batoideos vivíparas de importancia comercial en la costa mexicana del Pacífico. Sin embargo, ninguna de las 2 cuenta con planes de manejo adecuados para asegurar su uso sustentable. Los objetivos de este estudio fueron evaluar el potencial reproductivo y la tasa potencial de aumento poblacional (rʹ) de ambas especies, así como contrastar sus estrategias reproductivas para inferir qué tan susceptibles son a la explotación pesquera. Comparativamente, entre los batoideos, las hembras deN. entemedortienen edad de madurez temprana, fecundidad relativamente alta y longevidad intermedia, mientras que las hembras deR. steindachneritienen edad de madurez temprana, fecundidad baja y longevidad relativamente corta. Sin embargo, de acuerdo con las estimaciones de este estudio, ambas especies tienen un potencial reproductivo relativamente alto,N. entemedora través de la inversión de energía para maximizar la fecundidad yR. steindachneria través del incremento de la masa corporal embrionaria. Por lo tanto,N. entemedortiene mejor capacidad para recuperarse de una sobrepesca relativamente alta (rʹ = 0.48) en comparación conR. steindachneri(rʹ = -0.18). La metodología utilizada en este estudio demostró ser una buena opción para evaluar el riesgo de sobrepesca en especies para las cuales los datos son limitados.

Abstract: Oyster Crassostrea spp. is the bivalve mollusk with the largest commercial volume in Cuba. Populations should be assessed for their management and conservation, which has been performed but with different methodologies and only in certain localities, making it difficult to evaluate and compare between periods and regions. Therefore, current state of the resource was to be determined according to maximum sustainable yield (MSY), biomass for the maximum sustainable yield (BMSY), and corresponding fishing mortality rate (FMSY). Catch Maximum Sustainable Yield (CMSY) model was applied with Monte Carlo method, resource biomass and exploitation were evaluated for northwestern (NW), northeastern (NE), southeastern (SE), and southwestern (SW) regions of the insular platform, as well as for periods (1960-1991 and 1992-2020). From 1992-2020, a 50% reduction in oyster landings was recorded when compared with 1960-1991 period, which was reflected in population indicators according to estimated fishery reference points. Based on applied model and method, current oyster fishery management is perceived as unsustainable with stock depletion and overfishing in NW, NE, and SW regions. Cuban SE region shows a more favorable status. Oyster farming should increase to obtain higher production and broodstock biomass to decrease fishing effort on wild populations.

Resumen: En Cuba, la ostra Crassostrea spp. es el molusco bivalvo de mayor volumen comercial. La evaluación de sus poblaciones es necesaria para su manejo y conservación, pero se ha realizado con diferentes metodologías y solo en localidades puntuales, lo que dificulta su evaluación y comparación entre periodos y regiones. Por lo tanto, se determinó el estado actual del recurso según el rendimiento máximo sostenible (MSY), biomasa para el rendimiento máximo sostenible (BMSY) y la tasa de mortalidad por la pesca (FMSY) correspondiente. Se aplicó el modelo CMSY con método de Monte Carlo, y se evaluó la biomasa y la explotación del recurso para las regiones noroeste (NW), noreste (NE), sureste (SE) y suroeste (SW) de la plataforma insular, así como por periodos (1960-1991 y 1992-2020). Durante 1992-2020 se registró una reducción del 50% en los desembarques de ostras respecto al periodo 1960-1991, lo que se reflejó en los indicadores poblacionales según los puntos de referencia evaluados. De acuerdo con el modelo y método aplicados, la gestión pesquera actual de la ostra se percibe no-sostenible, con agotamiento del stock y sobrepesca en las regiones NW, NE y SW. La región SE del país presenta un estado más favorable. Se sugiere incrementar la ostricultura para obtener mayor producción y biomasa de reproductores para disminuir el esfuerzo de pesca sobre las poblaciones silvestres.

Resumo Na pesca, o fenômeno fishing down food webs, ou ‘pescando teias tróficas abaixo’, expressa a redução do nível trófico na composição das capturas, e tem origem tradicionalmente atribuída à sobrepesca. Sob intenso extrativismo, a resiliência das espécies carnívoras, predadoras de topo, é particularmente afetada, sendo seus estoques os primeiros a entrarem em depleção. A cavala, ou serra, ou sororoca, Scomberomorus brasiliensis, é exemplo de recurso predador historicamente alvo da pesca artesanal, de pequena escala, na costa brasileira. O presente trabalho analisa os valores de desembarque do recurso em três períodos ao longo de 50 anos na costa paranaense, sul do Brasil, com objetivo de avaliar se sua produção tem efetivamente diminuído. Ainda, estuda-se a dieta da espécie na região, para confirmar seus hábitos carnívoros e avaliar o nível trófico na região. Os resultados mostram que, surpreendentemente, dos anos 1970 para 2019 a produção de S. brasiliensis tem aumentado em valores absolutos, bem como relativamente à de outros recursos, em que pese o nível trófico 4,238, similar a outras espécies do gênero. Constata-se que a pesca da cavala na região de estudo constitui um caso de aumento nos desembarques a despeito de elevado nível trófico e grande tamanho corpóreo. Os resultados concordam com recente levantamento em nível mundial, que nega existir correlação necessária entre sobrepesca e nível trófico alto, mas fatores que podem explicar os resultados do presente trabalho são discutidos.

Abstract In fisheries, the phenomenon known as fishing down food webs is supposed to be a consequence of overfishing, which would be reflected in a reduction in the trophic level of landings. In such scenarios, the resilience of carnivorous, top predator species is particularly affected, making these resources the first to be depleted. The Serra Spanish mackerel, Scomberomorus brasiliensis, exemplifies a predator resource historically targeted by artisanal fisheries on the Brazilian coast. The present work analyzes landings in three periods within a 50-year timescale on the Parana coast, Southern Brazil, aiming to evaluate whether historical production has supposedly declined. Simultaneously, the diet was analyzed to confirm carnivorous habits and evaluate the trophic level in this region. Surprisingly, the results show that from the 1970’s to 2019 Serra Spanish mackerel production grew relatively to other resources, as well as in individual values. The trophic level was calculated as 4.238, similar to other Scomberomorus species, consisting of a case where landings increase over time, despite the high trophic level and large body size of the resource. The results agree with a recent global assessment that has demystified a necessary correlation between high trophic level and overexploitation, but possible factors acting on the present findings are discussed.

RESUMEN Con el propósito de evaluar el estado del pargo rayado Lutjanus synagris a partir de datos limitados de longitudes provenientes de los desembarcos de las capturas de la pesca artesanal registradas entre 2006 y 2012 en los Parques Nacionales Naturales Tayrona y Corales del Rosario y de San Bernardo y la Vía Parque Isla de Salamanca, se aplicaron indicadores simples y la metodología árbol de decisiones. Se observó un patrón de selectividad en la captura mayoritaria de ejemplares inmaduros (<L mat ) y un nivel de biomasa desovante inferior al punto de referencia límite objetivo, afectando la renovación natural de los stocks de L. synagris. También se ratificó el grado de sobrepesca por crecimiento y reclutamiento. Propender por la disminución de la presión sobre el pargo es un objetivo de manejo que requiere mayor protección en las tres áreas protegidas como zonas fuente, así como un ordenamiento regional participativo para la sostenibilidad del recurso. Por tanto, se recomienda llegar a acuerdos de conservación que propendan por una pesca responsable de peces maduros. Esto, permitirá un máximo rendimiento en biomasa y mejores ingresos económicos para los pescadores. Se propone la metodología descrita para la evaluación de otros recursos aprovechados en las áreas protegidas.

ABSTRACT With the purpose of evaluating the status of the lane snapper Lutjanus synagris from limited catch length data from the landings of artisanal fishing catches recorded between 2006 and 2012 in Tayrona and Corales del Rosario y de San Bernardo National Parks, and the Vía Parque Isla de Salamanca, simple indicators and the decision tree methodology were applied. it was observed that this indicator mostly configured a selectivity pattern represented in capture of mayoritary immature specimens (<L mat ) and a spawning biomass level lower than the target reference point, affecting the natural renewal of L. synagris stocks. Also, it was ratified the degree of overfishing for growth and recruitment to which L. synagris is subjected. Reducing pressure on snapper resource is a management objective that requires greater protection in the three protected areas for their ability to export the resource, as well as participatory regional fisheries management for the sustainability of the resource. Therefore, it is recommended to reach conservation agreements that promote responsible fishing of mature fish. This objective will allow maximum biomass yield, and better economic income for fishers. We also propose to apply the methodology described in this study to evaluate other fishery resources caught in the protected areas.

Abstract Small-scale fishing is relevant. However, aspects such as overfishing, the human population growth, the state of the fishing stocks, influence the adoption of economic diversification strategies by fishers. This article investigates how this process evolves, identifying successes and challenges, and its contributions to the SDGs of the 2030 Agenda. A scope review and critical analysis of publications from 2017 to 2022 was carried out. It was found that the diversification process takes place worldwide, regardless of the differences between fleets. Diversification shows two main paths of evolution: in fishing activities and in non-fishing activities according to the heritage of each region, highlighting tourist activities, transportation services, food and aquaculture. Public policy, training and the integration of academic knowledge are identified as elements of success, while market control by wholesalers, quota systems and a weak governance stand out as challenges. Important contributions to food security, poverty reduction and decent jobs are recognized. There is no conclusive evidence of its impacts on healthy ecosystems.

Resumen La pesca de pequeña escala es relevante. Sin embargo, aspectos como la sobrepesca, el crecimiento de la población humana, el estado de los stocks, influyen en la adopción de estrategias de diversificación económica por los pescadores. Este artículo investiga cómo evoluciona este proceso, identificando éxitos y desafíos, y sus contribuciones en los ODS de la Agenda 2030. Se realizó una revisión de alcance y análisis crítico de publicaciones del 2017 al 2022. Se encontró que el proceso de diversificación se gesta a nivel mundial, independientemente de las disimilitudes entre flotas. La diversificación muestra dos vías principales de evolución: en las actividades pesqueras y en actividades no pesqueras de acuerdo al patrimonio de cada región, destacando actividades turísticas, servicios de transporte, alimentos y acuicultura. La política pública, la capacitación y la integración del conocimiento académico se identifican como elementos de éxito, mientras que el control del mercado por mayoristas, sistemas de cuotas y una débil gobernanza destacan como desafíos. Se reconocen aportes importantes en seguridad alimentaria, reducción de pobreza y empleos dignos. No hay evidencia concluyente de sus impactos en ecosistemas sanos.

RESUMEN La estimación precisa de curvas de selectividad de redes de enmalle en una población de peces es un requisito importante para la sostenibilidad de los stocks explotados. Sin embargo, los trabajos de selectividad para artes de pesca que operan en ecosistemas continentales de Colombia son muy escasos. Este estudio determinó los parámetros de selectividad de redes de enmalle utilizadas en la captura del bocachico (Prochilodus magdalenae). El diseño experimental evaluó tres tamaños de malla (5,72; 6,35 y 8,89 cm) y las capturas se realizaron en diferentes sitios de pesca de la ciénaga de Zárate. Con la utilización del método SELECT se estimaron los parámetros de selectividad y mediante un análisis de Kruskall Wallis se determinaron las diferencias en la captura por unidad de esfuerzo. Además, el tamaño de malla óptimo fue calculado a partir del principio de similaridad geométrica de Baranov. Los resultados muestran que el modelo normal con varianza proporcional al tamaño de malla es el que mejor ajuste presentó para la captura de bocachico. Las longitudes modales calculadas con el modelo normal con varianza proporcional al tamaño de malla fueron 22,90, 25,45 y 35,63 cm para tamaños de malla de 5,72, 6,35 y 8,89 cm, respectivamente. El tamaño de malla óptimo calculado fue 6,99 cm. Los resultados indican que las redes con tamaños de malla de 5,72 cm e inferiores tienen un efecto sobre la estructura de tamaños del bocachico. Estas redes requieren ser priorizadas en la formulación de medidas de manejo basadas en la ordenación de este arte de pesca, lo que permitirá la sostenibilidad de la pesquería.

ABSTRACT Accurate estimation of gillnet selectivity curves in a fish population is an important requirement for the sustainability of exploited stocks. However, selectivity studies for fishing gear operating in Colombia's inland ecosystems is very rare. This study determined the gillnet selectivity parameters used in the catch of the bocachico (Prochilodus magdalenae). The experimental design evaluated three mesh sizes (5.72, 6.35 and 8.89 cm) and the catches were made in different fishing sites at the Zárate swamp. With the use of the SELECT method, the selectivity parameters were estimated and the Kruskall Wallis test determined the differences in the catch per unit effort. Furthermore, the optimal mesh size was calculated from Baranov's principle of geometric similarity. The results show that the normal model (scale) presented the best fit for the catch of bocachico. The modal lengths calculated with the normal scale model were 22.90, 25.45, and 35.63 cm for mesh sizes of 5.72, 6.35, and 8.89 cm, respectively. The calculated optimal mesh size was 6.99 cm. The results indicate that nets with mesh sizes of 5.72 cm and lower influences the size structure of the bocachico. These nets need to be prioritized in the formulation of management measures based on the regulation of this fishing gear, which will allow the sustainability of the fishery.

Resumo O marisco branco é um bivalve de areia que habita as praias dissipativas do sul do Brasil até a costa norte da Argentina. Nas últimas décadas, as populações desta espécie têm sido afetadas por eventos de mortalidade maciça, sobrepesca e outras atividades antropogênicas. A produção de juvenis em cativeiro permitiria a realização de estudos de viabilidade para restaurar o estoque natural, assim como a produção em sistemas de aquicultura. Dada a escassez de estudos sobre a manutenção desta espécie em cativeiro, um sistema de cultivo e um protocolo de manejo foram desenvolvidos e testados. Mariscos branco selvagens (comprimento total ≥50 mm) foram utilizados em uma série de ensaios de 14 dias de duração. A sobrevivência foi maior nos mariscos que podiam ser enterrados na areia. Um marcador de tinta permanente coberto com uma fina camada de adesivo de endurecimento rápido provou ser um método confiável para marcar os mariscos. A manutenção dos mariscos neste sistema resultou em alta sobrevivência e crescimento, aumento do fator de condição e do diâmetro do ovócito, e um relativo avanço do desenvolvimento gonadal.

Abstract The yellow clam is a sand-burrowing bivalve that inhabits the dissipative beaches from southern Brazil to the north coast of Argentina. In the last decades, populations of this species have been impacted by mass mortality events, overfishing and other anthropogenic activities. The production of juveniles in captivity would allow feasibility studies to be carried out to restore the natural stock as well as the production in aquaculture systems. Given the scarcity of studies on the maintenance of this species in captivity, a culture system and a management protocol were developed and tested. Wild-caught clams (total length ≥50 mm) were used in a series of 14 day-long trials. Survival was higher in clams that were allowed to bury into the sand. A permanent ink marker covered with a thin layer of a quick-hardening adhesive proved to be a reliable method to tag clams. The maintenance of yellow clams in this system resulted in high survival and growth, increases in the condition factor and oocyte diameter, and a relative advancement of gonadal development.

Abstract In the upper Paraná River floodplain, the populations of Salminus brasiliensis have been subjected to several anthropic impacts, such as overfishing, the blocking of migratory routes by dams, and regulation of the flood regime. Its populations have disappeared or become depleted in most rivers in this basin. These populations are the target of protection measures aimed at restoring them. This study evaluated the abundance of this species in the upper Paraná River floodplain over a 26-year time series in sites under different degrees of protection. Despite the overall decrease in the abundance of S. brasiliensis across the region, the less impacted sites have higher abundances and exhibited a slower decline in the probability of occurrence. Over time, populations in less impacted sites also exhibited improved fish condition. Some protected areas in the upper Paraná River have had a mitigation effect by lowering the velocity of population decline and representing a constant source of propagule production for other areas. Our results reinforce the notion that populations threatened with low abundances take a long time to effectively recover their stocks. Thus, besides evaluating species conservation strategies, long-term studies are essential to subsidize management measures, such as fisheries regulations. impacts overfishing dams regime basin them 26year year 26 S region occurrence condition stocks Thus strategies longterm term regulations 2

Resumo Na planície de inundação do alto rio Paraná, as populações de Salminus brasiliensis têm sido submetidas a diversos impactos antrópicos, como sobrepesca, bloqueio de suas rotas migratórias por barragens e regulação do regime de cheias. Essas populações desapareceram ou se esgotaram na maioria dos rios dessa bacia, sendo alvo de medidas de proteção para restaurá-las. O objetivo deste trabalho foi avaliar a abundância da espécie na planície de inundação do alto rio Paraná ao longo da série temporal de 26 anos em locais sob diferentes graus de proteção. Apesar da diminuição geral na abundância de S. brasiliensis em toda a região, os locais menos impactados possuem maiores abundâncias e exibiram um declínio mais lento na probabilidade de ocorrência. Com o tempo, as populações em locais menos impactados apresentaram aumento na condição dos peixes. Algumas áreas de proteção no alto rio Paraná têm efeito mitigador, diminuindo a velocidade de declínio populacional, representando fonte de propágulos para as demais áreas. Nossos resultados reforçam a ideia de que populações ameaçadas com baixas abundâncias levam muito tempo para recuperar seus estoques. Assim, além de avaliar as estratégias de conservação das espécies, estudos de longo prazo são essenciais para subsidiar medidas de manejo, como a regulamentação da pesca. antrópicos sobrepesca cheias bacia restaurálas. restaurálas restaurá las. las restaurá-las 2 S região ocorrência peixes mitigador populacional estoques Assim espécies manejo pesca

ABSTRACT The catfish Calophysus macropterus is heavily exploited in the Amazon basin, yet its life history characteristics are poorly documented, hampering proper fisheries management. In order to fill this gap, monthly sampling in the upper Putumayo River and in the Amazonas, lower Marañón and Ucayali (AMU) rivers were carried out over several years (2013-2015 in the AMU, 2013-2017 in the Putumayo) to provide detailed information about its reproduction, growth and mortality patterns (using length frequency data). Reproduction, which occurs during the dry and early flooding season, was only observed in the upper Putumayo River and not in the sampled portion of the AMU system, suggesting that the species reproduces closer to the Andes than other pimelodid catfishes. Size at first sexual maturity did not differ significantly among sex or among river systems, ranging from 25-28 cm SL. In both river systems, females had a faster growth than males and both genders also tended to have a better growth in the AMU than in the upper Putumayo. Mortality and exploitation estimate all indicated overexploitation of the species in both river systems. The implications of these results for fisheries management and conservation are discussed.

RESUMEN El bagre Calophysus macropterus está fuertemente explotado en la cuenca Amazónica. Sin embargo, su ciclo de vida está poco documentado, lo que dificulta su gestión pesquera. Para llenar este vacío, se realizaron muestreos mensuales en el alto río Putumayo alrededor de Puerto Leguízamo y en el Amazonas y los ríos bajo Marañón y Ucayali (AMU) cerca de Iquitos durante varios años (2013-2015 en AMU, 2013-2017 en Putumayo) para generar información sobre su reproducción, crecimiento y mortalidad. La reproducción, que se produce durante la estación seca y el inicio de la inundación, sólo se observó en el curso superior del río Putumayo y no en la parte muestreada del sistema de la AMU, lo que sugiere que la especie se reproduce más cerca de los Andes que otros pimelodidos. El tamaño de primera madurez sexual no difirió entre sexos o entre sistemas fluviales, oscilando entre 25-28 cm. En ambos sistemas fluviales, las hembras tuvieron un crecimiento más rápido que los machos y ambos géneros también tendieron a tener un mejor crecimiento en el AMU que en el alto Putumayo. Estimaciones de mortalidad y explotación indicaron una sobreexplotación en ambos sistemas. Se discuten las implicaciones de estos resultados para la gestión y conservación de las pesquerías.