Flotas de pesca extranjeras en el Pacífico costarricense y su traslape con áreas protegidas oceánicas, el ordenamiento pesquero y el Domo Térmico / Foreign fishing fleets in the Costa Rican Pacific and their overlap with oceanic protected areas, the fishing zoning, and the Thermal Dome

Introduction: Until today, the fishing effort by foreign fleets in the Costa Rican Pacific has not been analyzed. Objective: To determine the spatial distribution of the fishing effort of those fleets, variables that shape that distribution, and if they interact with management figures and highly fragile ecosystems. Methods: Using fishing effort data from 2012 to 2020, obtained from Global Fishing Watch, an Index of Fishing Effort (IEP) was calculated to apply geospatial and multivariate statistics, as well as multiple regression models. A grid with 55 905 cells of 0.10 degrees was used to apply Hot Spot Analysis, and another grid with 24 176 cell-year-month analysis units of 0.25 degrees was used to apply a Linear Regression Model. Results: The data reveals the fishing activity of international fleets associated with four types of fishing gear, and a wide coverage of a high IEP by two fleets throughout the nine years analyzed. The IEP is primarily associated with location and varies by month and year. There is also relative evidence that its influenced by the concentration of oxygen and nitrates. Conclusions: International fleets come into direct conflict with officially defined zones for national fleets and disrespect protected oceanic areas and a declared non-fishing zone to protect marine resources in the Costa Rican Pacific. Their activities in the Dome may affect a national yellowfin tuna fishery.

Introducción: Hasta hoy, no ha sido analizado el esfuerzo pesquero por parte de flotas extranjeras en el Pacífico de Costa Rica. Objetivo: Determinar la distribución espacial del esfuerzo pesquero de esas flotas, variables que moldean esa distribución, y si las mismas interactúan con figuras de manejo y ecosistemas altamente frágiles. Métodos: A partir de datos de esfuerzo pesquero de 2012 a 2020, obtenidos de Global Fishing Watch, fue calculado un Índice de Esfuerzo Pesquero (IEP) sobre el cual fue aplicada estadística geoespacial y multivariada, así como modelos de regresión múltiple. Fue utilizada una cuadrícula con 55 905 celdas de 0.10 grados, para aplicar Análisis de Puntos Calientes, y otra cuadrícula con 24 176 unidades de análisis celdas-año-mes de 0.25 grados, para aplicar un Modelo de Regresión Lineal. Resultados: Los datos revelan la actividad pesquera de las flotas internacionales asociadas a cuatro tipos de artes de pesca, así como una amplia cobertura de alto IEP por parte de dos flotas a lo largo de los nueve años analizados. El IEP se asocia principalmente con la ubicación y varía según el mes y el año. También hay evidencia relativa de que está influenciado por la concentración de oxígeno y nitratos. Conclusiones: Las flotas internacionales entran en conflicto directo con zonas oficialmente delimitadas para las flotas nacionales e irrespetan las áreas oceánicas protegidas y una zona no pesquera declarada para proteger los recursos marinos en el Pacífico costarricense. Sus actividades en el Domo pueden afectar la pesquería de atún aleta amarilla.

Cambios históricos en el esfuerzo pesquero de la flota parguera de Taganga, Caribe Colombiano / Historical changes in the fishing effort of the parguera fleet of Taganga, Colombian Caribbean

RESUMEN La pesquería artesanal avanzada de lanchas "pargueras" que opera en el área norte del mar Caribe de Colombia ha experimentado grandes dificultades relacionadas con el volumen de los desembarcos, que han llevado al colapso económico de la flota. La disminución de la abundancia de los recursos ícticos ha ocasionado la expansión del área de pesca, el aumento en la duración del viaje de pesca, la disminución de los ingresos y el incremento de los gastos de operación. Existen vacíos en el conocimiento de la distribución espacial actual e histórica del esfuerzo pesquero de la flota, que no permiten asociarlos a los cambios en las abundancias, la composición de las capturas y la disminución de tamaños de las especies capturadas. Mediante entrevistas a pescadores y con la ayuda del conocimiento ecológico tradicional, el conocimiento local y el uso de sistemas de información geográfica, se mapeó la distribución espacial del esfuerzo pesquero y su comportamiento desde los años 70 hasta la actualidad. Como principal resultado, se evidenció un aumento promedio de 134,5km en la distancia del viaje de pesca en casi 50 años y cambios en el área y profundidades de pesca, que variaron desde los 27,8 a 1117,8km2 y de los 93,8 a 41,1m, respectivamente. Los resultados obtenidos constituyen insumos valiosos para la implementación de estrategias de manejo, orientadas a asegurar la sostenibilidad ecológica y la viabilidad económica de esta importante pesquería.

ABSTRACT The advanced artisanal fishery of fishing boats called "pargueras" that operates in the northern area of the Colombian Caribbean has experienced great difficulties related to the volume of landings that have led to the economic collapse of the fleet. The decrease in the abundance of fish resources has caused an expansion of the fishing area, increased duration of the fishing trip, decreased incomes and the increase in operating expenses. Existing knowledge gaps with respect to current and historical spatial distribution of the fleet's fishing effort prevent an association to changes in resource abundances, composition of catches and decreased species catch sizes. Through interviews with fishermen and based in traditional ecological knowledge, local knowledge and the use of geographic information systems, we mapped the spatial distribution of fishing effort and its inter-decadal behavior, from the 70s to present. The main result was a 134.5km increase in the distance of an average fishing trip in almost 50 years and changes in the surface area and fishing depths which varied from 27.8 to 1117.8km2 and 93.8 to 41.1m, respectively. The results obtained constitute valuable inputs for the implementation of management strategies aimed at ensuring the ecological sustainability and economic viability of this important fishery.

Bioecology and movements of bull sharks, Carcharhinus leucas, caught in a long-term longline survey off northeastern Brazil

A robust understanding of habitat usage by coastal shark species, and how it overlaps with human presence in densely-populated regions is needed to inform the development of efficient conservation strategies for these important top predators. An intensive longline survey conducted in nearshore waters off northeastern Brazil from 2004 through 2014 caught a total of 18 bull sharks (Carcharhinus leucas) (male-female ratio = 0.63:1), which can be dangerous to humans. Although most sharks were sexually mature, there was no evidence that this region could be used as a parturition or nursery area. Prey items identified in the guts of the sharks comprised teleosts, mollusks and elasmobranchs. Additionally, one satellite-tagged bull shark covered a great distance (> 3,000 km) in 75 days at liberty, making most use of shallow waters (< 20 m depth) and presumably also entering an estuarine area. Although bull sharks are not an important fishery resource in this region, such a reduced abundance coupled with its affinity for coastal and inshore habitats highlights the potential vulnerability of C. leucas to deleterious anthropic interferences off northeastern Brazil.(AU)

Um melhor entendimento sobre a utilização de hábitat das espécies de tubarões costeiros, e como ela se sobrepõe à presença humana em regiões altamente populosas, se faz necessário a fim de subsidiar o desenvolvimento de eficientes medidas de conservação para esses importantes predadores de topo. Um estudo intensivo utilizando espinhel, conduzido em águas costeiras do nordeste do Brasil entre os anos de 2004 e 2014, capturou um total de 18 tubarões cabeça-chata (Carcharhinus leucas) (proporção macho-fêmea = 0,63:1), os quais podem ser perigosos para humanos. Apesar da maioria dos tubarões estarem sexualmente maduros, não houve evidências de que essa região esteja sendo utilizada como uma área de parto ou berçário. Entre os itens alimentares identificados foram encontrados teleósteos, moluscos e elasmobrânquios. Além disso, um tubarão cabeça-chata marcado com um transmissor satélite percorreu uma grande distância (> 3.000 km) em 75 dias em liberdade, fazendo o uso de águas superficiais (< 20 m profundidade) e presumivelmente entrando em uma área estuarina. Apesar de os tubarões cabeça-chata não corresponderem a um recurso pesqueiro importante nessa região, tal reduzida abundância juntamente com a sua afinidade por hábitats costeiros reforçam a potencial vulnerabilidade de C. leucas às interferências antrópicas deletérias ao longo da costa nordeste do Brasil.(AU)

Captura, esfuerzo y captura incidental de la pesca con espinel en el centro de Perú

El objetivo del presente trabajo es dar a conocer algunas características de los viajes de pesca, esfuerzo, captura, peces objetivos, áreas de pesca y captura incidental obtenida a partir de observadores a bordo y bitácoras de pesca. El 85% de los lances se produjeron en los primeros 574 Km de distancia a la costa (309 millas náuticas). El lance más distante estuvo a 1320 Km (712 millas náuticas). Se lanzaron 382000 anzuelos para perico, en 224 lances y 29 viajes de pesca, 94.6% de la captura en peso fue de perico, 2.7% de tiburón azul (Prionace glauca) y 1.3% de diamante (Isurus oxyrinchus). Además, 103790 anzuelos capturaron tiburón, en 109 lances y 12 viajes de pesca, 81,9% de la captura en peso fue de tiburón azul y 16.8% de diamante. La Captura por Unidad de Esfuerzo (CPUE) para perico mostró diferencias significativas entre estaciones, con un máximo entre noviembre y enero. En lo que refiere a tiburón, la CPUE por estaciones también mostró diferencias significativas, los meses con mayores capturas fueron setiembre y octubre. La tortuga verde, Chelonia mydas agassizii, fue la más capturada y dos de cada tres fueron juveniles. Todas las tortugas cabezonas, Caretta caretta, fueron juveniles. Se reporta la captura de un petrel y al parecer, la captura de mamíferos sería escasa. Considerando el gran esfuerzo de esta pesquería, existe la necesidad de monitorearla para contar con información que permita establecer las correspondientes medidas de manejo.

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.

Description of diet of pelagic fish in the southwestern Atlantic, Brazil / Descrição da dieta de peixes pelágicos no Oceano Atlântico, Brasil

This study reveals the food composition of pelagic fishes living in the southwestern Atlantic Ocean. As such more common pelagic species are considered to be top predators, the study proposes to know what constitutes their main food. Fish are not commonly found within their stomach contents, but instead, cephalopods are their most common food. As can be observed, Teuthida cephalopods compose their principal diet. The stomach contents of specimens of Xiphias gladius, Thunnus albacares, T. obesus, T. alalunga, Isurus oxyrinchus and Alopias superciliosus caught during July 2007 to June 2009 by using tuna longliners were studied. Teuthida cephalopods constitute the main food item for the three tuna species, while X. gladius feeds mainly on Ommastrephidae cephalopods. Though the differences among the kinds of cephalopods exist, they constitute the principal resource these fish use to live at least in the southern Atlantic Ocean.

Este estudo descreve a composição da dieta de peixes pelágicos que vivem no Oceano Atlântico Sudoeste. Como tais espécies pelágicas são consideradas predadoras de topo, o estudo propõe conhecer o que constitui sua principal fonte de alimento. Peixes não são comumente encontrados em seus conteúdos estomacais, em vez disso, os cefalópodes são os alimentos mais comuns. Como pode ser observado, cefalópodes Teuthida compreendem sua dieta principal. O conteúdo estomacal de espécimes de Xiphias gladius, Thunnus albacares, T. obesus, T. alalunga, Isurus oxyrinchus e Alopias superciliosus, capturados durante julho de 2007 a junho de 2009 prela frota atuneira, foram estudados. Cefalópodes Teuthida constituem o principal item alimentar das três espécies de atum, enquanto X. gladius alimenta-se principalmente de cefalópodes Ommastrephidae. Embora as diferenças entre os tipos de cafalópodes existam, eles constituem o principal recurso que estes peixes usam para viver, pelo menos no Oceano Atlântico Sudoeste.

La pesquería de tiburones oceánicos-costeros en los litorales de Colima, Jalisco y Michoacán

Fishery of oceanic and coastal sharks in Colima, Jalisco and Michoacán. Shark fishery is one of the most important activities in the Mexican Pacific coast, nevertheless, there is few data available about the specific captures done by the fleet along the coast. This study describes fishery biology aspects of the shark species catched by the semi-industrial long-line fleet of Manzanillo. Monthly samplings were made on board of these vessels during an annual period from April 2006 to April 2007. Captured species composition (n=1 962 organisms) was represented by nine species. The one that sustains this fishery was Carcharhinus falciformis (88.12%), followed by Prionace glauca (8.21%). Low frequency species were represented by Sphyrna zygaena (1.78%), Alopias pelagicus (0.82%), Carcharhinus longimanus (0.45%). Furthermore, rare species were Alopias superciliosus (0.35%), Carcharhinus leucas (0.1%), Carcharhinus limbatus (0.1%) and Isurus oxyrinchus (0.05%). Fishery activity affected principally (60-92.70%) young males of C. falciformis, S. zygaena, C. longimanus and I. oxyrinchus; adult males (56-75%) of A. pelagicus, A. superciliosus, and C. limbatus; for P. glauca there were primarily female adults. For all the species found, females showed the bigger sizes when compared to males (with the exception of S. zygaena, that showed sexual dimorphism). Considering the lineal regressions made between precaudal length and total length, and, fork length and total length for C. falciformis, P. glauca, S. zygaena and A. pelagicus, the determination coefficients (r²) showed that both lengths can be useful to obtain the total length of fish with some damage or absence of its caudal fin. The estimated fecundity for C. falciformis was of 3-7 offspring/female of 30-45cm LT (average of 40.57+2.03cm LT); and for P. glauca 5-52offspring/female of 5-18.6cm LT (average of 11.61±0.21cm LT). In the case of C. longimanus only one female was captured with a total of eight embryos, with an average of 45cm LT each; for this reason we assumed that the fishery areas do not coincide with the nursery oness for this species. According to the information obtained, we concluded that C. falciformis has a concurrent cycle and P. glauca a consecutive biannual one. Rev. Biol. Trop. 59 (2): 655-667. Epub 2011 June 01.

La pesquería de tiburón es una de las más importantes en el Pacífico mexicano, en la actualidad no se cuentan con los datos de la composición específica de las capturas de las diferentes flotas. En el presente trabajo se describen aspectos biológicos-pesqueros de las especies de tiburón, capturadas por la flota palangrera de mediana altura del puerto de Manzanillo, en un periodo anual de abril 2006-abril 2007, los muestreos se realizaron mensualmente a bordo de estas embarcaciones. La composición de las capturas estuvo representada por nueve especies (n=1 962), de las cuales Carcharhinus falciformis (Bibron, 1839) (88.12%) sostiene esta pesquería y en segundo lugar Prionace glauca (Linnaeus, 1758) (8.21%). Las especies poco frecuentes fueron Sphyrna zygaena (Linnaeus, 1758) con (1.78%), Alopias pelagicus (Nakamura, 1935) (0.82%), Carcharhinus longimanus (Poey, 1861) (0.45%), Alopias superciliosus (Lowe, 1839) (0.35%), Carcharhinus leucas (Valenciennes, 1839) (0.1%), Carcharhinus limbatus (Valenciennes, 1839) (0.1%) é Isurus oxyrinchus (Rafinesque, 1810) (0.05%). La fecundidad estimada para C. falciformis fue de 3-7 crías/hembra con tallas de 30-45cm LT; 40.57+2.03cm LT y P. glauca con 5-52 crías/hembra, con tallas de 5-18.6cm LT; 11.61±0.21cm LT. Por lo tanto se asume que C. falciformis presenta un ciclo concurrente y P. glauca probablemente un ciclo bianual consecutivo.

Impact of commercial fishing on Trindade Island and Martin Vaz Archipelago, Brazil: characteristics, conservation status of the species involved and prospects for preservation

Visual records, radio interviews and onboard observations of the fishing activities during a 58 days scientific expedition to Trindade Island and the Martin Vaz Archipelago were obtained from February to April 2007. The regular activities of four different fisheries were observed: pelagic longline, bottom line, trolling and handline. These fisheries caused mortality of at least seven species with some level threat, according to the International Union for Conservation of Nature list. The establishment of specific restriction norms for hook-and-line activities around the oceanic islands was seen as an alternative for the conservation of the ichthyofauna of the region. Satellite monitoring to track the fishery vessels could be established through the national program as another legal mean to diminish fishing the impact.

Reportamos atividades de pesca comerciais no complexo insular mais afastado da costa brasileira: Ilha da Trindade e Arquipélago Martin Vaz. As atividades foram estudadas através de embarques e entrevistas com os mestres e pescadores das embarcações durante uma expedição cientifica realizada entre fevereiro e abril de 2007. Quatro modalidades de atividades de pesca são realizadas na região, capturando ao menos sete espécies que possuem algum risco de extinção. O estabelecimento de normas específicas de restrição para atividades que pescam sobre os recifes das ilhas é uma alternativa para a conservação das espécies ameaçadas. O monitoramento das embarcações pode ocorrer via satélite através do programa nacional de rastreamento de embarcações pesqueiras (PREPS).