Diversidad de moluscos asociados a manglares en isla San Lucas

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Abundancia y riqueza de peces en la isla San Lucas

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Abundancia, reproducción y tallas del tiburón martillo Sphyrna lewini (Carcharhiniformes: Sphyrnidae) en la pesca artesanal de Golfo Dulce, Pacífico de Costa Rica

Incidental catch of S. lewini by artisanal fishermen in Golfo Dulce, Costa Rica, suggest that this could be one of the coastal locations used by the species. This study aims to characterize the scalloped hammerhead shark population in Golfo Dulce, in order to best guide management actions for the conservation and sustainable use of the species. Fisheries-dependent biological data (size-TL, sex, reproductive status) were gathered for S. lewini between May 2010 and May 2011 in the communities of Puerto Jimenez and Pavones, Golfo Dulce during artisanal fishing trips. Catch per unit effort (CPUE) throughout the year was also estimated from catch data. We sampled a total of 315 sharks. Mean total length was estimated at 74.3±17.4cm. Both pups and juveniles were reported, which presented a male: female ratio of 1:1.2 (p>0.05). Total length and relative abundance of S. lewini had opposite tendencies, with the smallest TL (64cm) recorded during July-August, when CPUE was highest. (0.0075). Temporary closures from June to August are therefore recommended at areas of highest reported catch (Pique Fijo, Los Bajos y La Ciénaga), in order to protect newly born S. lewini, and promote the sustainability of the species in the ETPS Closures should be complemented with a long-term study that can further clarify whether Golfo Dulce is a nursery area for S. lewini. En Golfo Dulce, Costa Rica, se han reportado capturas incidentales de S. lewini por pescadores artesanales. Debido a esto, este estudio tiene como objetivo caracterizar las capturas del tiburón martillo en Golfo Dulce, y recomendar pautas de manejo. Entre mayo 2010 y mayo 2011 se recopiló información biológica-pesquera de tiburones capturados durante faenas artesanales en Golfo Dulce. Se estimó la captura por unidad de esfuerzo a lo largo del año. Se analizaron un total de 315 tiburones, todos juveniles, con una longitud total media de 74.3±17.4cm. Las longitudes totales y la abundancia relativa tuvieron tendencias opuestas: en julio-agosto cuando las longitudes totales medias fueron menores, las capturas por unidad de esfuerzo fueron mayores. Debido a esto, se recomienda implementar vedas temporales durante el periodo de nacimiento de las crías de tiburón martillo (junio-agosto) en sitios donde se reportaron las mayores capturas.

CARACTERIZAÇÃO DA PESCA DO TUBARÃO-MARTELO-RECORTADO, SPHYRNA LEWINI, NA PARTE EXTERNA DO GOLFO DE NICOYA, COSTA RICA

En el ámbito nivel mundial, el tiburón martillo (Sphyrna lewini) es una de las especies más afectadas por la sobrepesca y el aleteo. Recientemente se incorporó a la Lista Roja de la UICN como especie en peligro de extinción. El presente estudio pretendió caracterizar la pesca y la distribución de S. lewini en la parte externa del Golfo de Nicoya. Para lograr este propósito, se realizaron muestreos entre marzo del 2006 y mayo del 2007 y se analizaron los tiburones martillo capturados por pescadores artesanales afiliados a la Cooperativa artesanales de Pescadores de Tárcoles (CoopeTárcoles R. L.), que faenan en la parte externa del Golfo de Nicoya. Para cada tiburón, se determinó la longitud total, la zona de pesca donde se capturó y el arte utilizado. En total se analizaron 273 tiburones. Se identificó un área de crianza primaria en el Peñón y se determinó que existe una relación lineal positiva entre la longitud total y la profundidad de la zona de pesca (R2 = 0.4296; p ‹ 0.0001), y la longitud total y la distancia de la zona de pesca de la desembocadura del río Grande de Tárcoles (R2 = 0.4052; p ‹ 0.0001). Los tiburones de menor tamaño (crías) se encontraron en la zona del Peñón, donde las aguas son poco profundas, turbias y productivas, ofreciendo a las crías alimento y protección de los depredadores. Por lo cual, se recomienda proteger esta zona, en particular en marzo, abril y mayo, época de nacimiento de las crías.The scalloped hammerhead shark (Sphyrna lewini) is one of the shark species most impacted by overfishing, and is currently listed by the IUCN Red List as an Endangered.  This research sought to characterize the distribution of S. lewini in the external area of Gulf of Nicoya, central Pacific coast of Costa Rica, based on observations from a coastal artisanal fishery. From March 2006 to May 2007, we analyzed scalloped hammerhead shark landings by members of the Tarcoles Artisanal Fishermen's Cooperative (CoopeTárcoles R. L.), who operate in the outer part of the Gulf of Nicoya. We measured the total length of each shark, recorded the reported location of capture, and the gear used. In total, we recorded data for 273 sharks landed. We determined that total length holds a positive linear relationship with the depth of the fishing area (R2 = 0.4296, *** p <.0001) as well as with the distance from the mouth of the Tárcoles River (R2 = 0.4052, *** p <.0001). The smaller sharks (pups) were caught in a fishing site known as Peñon, slightly north of the mouth of the Tarcoles River, where the waters are shallow, turbid and highly productive, providing food and shelter for the pups.  As pups mature and attain larger sizes, they move towards deeper waters away from the Tarcoles River, out of the Gulf of Nicoya. We identify Peñon as a primary nursery for scalloped hammerhead sharks, and recommend management actions that seek to reduce fishing effort between March and May, when pups are born.No âmbito mundial, o tubarão-martelo-recortado (Sphyrna lewini) é uma das espécies mais afetadas pela sobrepesca e pelo corte das barbatanas. Recentemente se incorporou à Lista Vermelha da UICN como espécie em perigo de extinção. O presente estudo pretendeu caracterizar a pesca e a distribuição de S. lewini na parte externa do Golfo de Nicoya. Para alcançar este propósito, realizaram amostragens entre março de 2006 e maio dl 2007 e analisaram-se os tubarões-martelo-recortado capturados por pescadores artesanais afiliados à Cooperativa de Pescadores Artesanais de Tárcoles (CoopeTárcoles R. L.), que pescam na parte externa do Golfo de Nicoya. Para cada tubarão determinou-se a longitude total, a zona de pesca onde se capturou e a arte utilizada. No total analisaram-se 273 tubarões. Identificou-se uma área de criação primária no Peñón e determinou-se que existe uma relação linear positiva entre a longitude total e a profundidade da zona de pesca (R2 = 0.4296; p ‹ 0.0001), e a longitude total e a distância da zona de pesca da desembocadura do rio Grande de Tárcoles (R2 = 0.4052; p ‹ 0.0001). Os tubarões de menor tamanho (filhotes) encontraram-se na zona do Peñón, onde as águas são pouco profundas, turvas e produtivas, oferecendo aos filhotes alimento e proteção dos predadores. Por essa razão, recomenda-se proteger esta zona, particularmente em março, abril e maio, época de nascimento dos filhotes.&nbsp

CARACTERIZAÇÃO DA PESCA DO TUBARÃO-MARTELO-RECORTADO, SPHYRNA LEWINI, NA PARTE EXTERNA DO GOLFO DE NICOYA, COSTA RICA

En el ámbito nivel mundial, el tiburón martillo (Sphyrna lewini) es una de las especies más afectadas por la sobrepesca y el aleteo. Recientemente se incorporó a la Lista Roja de la UICN como especie en peligro de extinción. El presente estudio pretendió caracterizar la pesca y la distribución de S. lewini en la parte externa del Golfo de Nicoya. Para lograr este propósito, se realizaron muestreos entre marzo del 2006 y mayo del 2007 y se analizaron los tiburones martillo capturados por pescadores artesanales afiliados a la Cooperativa artesanales de Pescadores de Tárcoles (CoopeTárcoles R. L.), que faenan en la parte externa del Golfo de Nicoya. Para cada tiburón, se determinó la longitud total, la zona de pesca donde se capturó y el arte utilizado. En total se analizaron 273 tiburones. Se identificó un área de crianza primaria en el Peñón y se determinó que existe una relación lineal positiva entre la longitud total y la profundidad de la zona de pesca (R2 = 0.4296; p ‹ 0.0001), y la longitud total y la distancia de la zona de pesca de la desembocadura del río Grande de Tárcoles (R2 = 0.4052; p ‹ 0.0001). Los tiburones de menor tamaño (crías) se encontraron en la zona del Peñón, donde las aguas son poco profundas, turbias y productivas, ofreciendo a las crías alimento y protección de los depredadores. Por lo cual, se recomienda proteger esta zona, en particular en marzo, abril y mayo, época de nacimiento de las crías.The scalloped hammerhead shark (Sphyrna lewini) is one of the shark species most impacted by overfishing, and is currently listed by the IUCN Red List as an Endangered.  This research sought to characterize the distribution of S. lewini in the external area of Gulf of Nicoya, central Pacific coast of Costa Rica, based on observations from a coastal artisanal fishery. From March 2006 to May 2007, we analyzed scalloped hammerhead shark landings by members of the Tarcoles Artisanal Fishermen's Cooperative (CoopeTárcoles R. L.), who operate in the outer part of the Gulf of Nicoya. We measured the total length of each shark, recorded the reported location of capture, and the gear used. In total, we recorded data for 273 sharks landed. We determined that total length holds a positive linear relationship with the depth of the fishing area (R2 = 0.4296, *** p <.0001) as well as with the distance from the mouth of the Tárcoles River (R2 = 0.4052, *** p <.0001). The smaller sharks (pups) were caught in a fishing site known as Peñon, slightly north of the mouth of the Tarcoles River, where the waters are shallow, turbid and highly productive, providing food and shelter for the pups.  As pups mature and attain larger sizes, they move towards deeper waters away from the Tarcoles River, out of the Gulf of Nicoya. We identify Peñon as a primary nursery for scalloped hammerhead sharks, and recommend management actions that seek to reduce fishing effort between March and May, when pups are born.No âmbito mundial, o tubarão-martelo-recortado (Sphyrna lewini) é uma das espécies mais afetadas pela sobrepesca e pelo corte das barbatanas. Recentemente se incorporou à Lista Vermelha da UICN como espécie em perigo de extinção. O presente estudo pretendeu caracterizar a pesca e a distribuição de S. lewini na parte externa do Golfo de Nicoya. Para alcançar este propósito, realizaram amostragens entre março de 2006 e maio dl 2007 e analisaram-se os tubarões-martelo-recortado capturados por pescadores artesanais afiliados à Cooperativa de Pescadores Artesanais de Tárcoles (CoopeTárcoles R. L.), que pescam na parte externa do Golfo de Nicoya. Para cada tubarão determinou-se a longitude total, a zona de pesca onde se capturou e a arte utilizada. No total analisaram-se 273 tubarões. Identificou-se uma área de criação primária no Peñón e determinou-se que existe uma relação linear positiva entre a longitude total e a profundidade da zona de pesca (R2 = 0.4296; p ‹ 0.0001), e a longitude total e a distância da zona de pesca da desembocadura do rio Grande de Tárcoles (R2 = 0.4052; p ‹ 0.0001). Os tubarões de menor tamanho (filhotes) encontraram-se na zona do Peñón, onde as águas são pouco profundas, turvas e produtivas, oferecendo aos filhotes alimento e proteção dos predadores. Por essa razão, recomenda-se proteger esta zona, particularmente em março, abril e maio, época de nascimento dos filhotes.&nbsp

Caracterización de la pesca del tiburón martillo Sphyrna lewini, en la parte externa del Golfo de Nicoya, Costa Rica

The scalloped hammerhead shark (Sphyrna lewini) is one of the shark species most impacted by overfishing, and is currently listed by the IUCN Red List as an Endangered.  This research sought to characterize the distribution of S. lewini in the external area of Gulf of Nicoya, central Pacific coast of Costa Rica, based on observations from a coastal artisanal fishery. From March 2006 to May 2007, we analyzed scalloped hammerhead shark landings by members of the Tarcoles Artisanal Fishermen's Cooperative (CoopeTárcoles R. L.), who operate in the outer part of the Gulf of Nicoya. We measured the total length of each shark, recorded the reported location of capture, and the gear used. In total, we recorded data for 273 sharks landed. We determined that total length holds a positive linear relationship with the depth of the fishing area (R2 = 0.4296, *** p <.0001) as well as with the distance from the mouth of the Tárcoles River (R2 = 0.4052, *** p <.0001). The smaller sharks (pups) were caught in a fishing site known as Peñon, slightly north of the mouth of the Tarcoles River, where the waters are shallow, turbid and highly productive, providing food and shelter for the pups.  As pups mature and attain larger sizes, they move towards deeper waters away from the Tarcoles River, out of the Gulf of Nicoya. We identify Peñon as a primary nursery for scalloped hammerhead sharks, and recommend management actions that seek to reduce fishing effort between March and May, when pups are born.En el ámbito nivel mundial, el tiburón martillo (Sphyrna lewini) es una de las especies más afectadas por la sobrepesca y el aleteo. Recientemente se incorporó a la Lista Roja de la UICN como especie en peligro de extinción. El presente estudio pretendió caracterizar la pesca y la distribución de S. lewini en la parte externa del Golfo de Nicoya. Para lograr este propósito, se realizaron muestreos entre marzo del 2006 y mayo del 2007 y se analizaron los tiburones martillo capturados por pescadores artesanales afiliados a la Cooperativa artesanales de Pescadores de Tárcoles (CoopeTárcoles R. L.), que faenan en la parte externa del Golfo de Nicoya. Para cada tiburón, se determinó la longitud total, la zona de pesca donde se capturó y el arte utilizado. En total se analizaron 273 tiburones. Se identificó un área de crianza primaria en el Peñón y se determinó que existe una relación lineal positiva entre la longitud total y la profundidad de la zona de pesca (R2 = 0.4296; p ‹ 0.0001), y la longitud total y la distancia de la zona de pesca de la desembocadura del río Grande de Tárcoles (R2 = 0.4052; p ‹ 0.0001). Los tiburones de menor tamaño (crías) se encontraron en la zona del Peñón, donde las aguas son poco profundas, turbias y productivas, ofreciendo a las crías alimento y protección de los depredadores. Por lo cual, se recomienda proteger esta zona, en particular en marzo, abril y mayo, época de nacimiento de las crías

ANÁLISE DAS CAPTURAS DE TUBARÕES E RAIAS NAS PESQUEIRAS ARTESANAIS DE TÁRCOLES, PACÍFICO CENTRAL DA COSTA RICA

Se analizaron las capturas de tiburones y rayas látigo realizadas por pescadores artesanales de Tárcoles&nbsp; en el Pacífico de Costa Rica, desde febrero del 2006 hasta febrero del 2007. Se observaron 415 faenas de pesca (línea de fondo, trasmallo y línea rayera): 340 correspondieron a observaciones de descarga y 75 (18.1%) a observaciones a bordo. Durante las descargas se analizaron 3299 tiburones y rayas látigo: el tiburón mamón enano (Mustelus henlei) dominó en la captura total (63.7%), seguido por el tiburón mamón común (Mustelus lunulatus) (16.7%), el tiburón picudo común (Rhizoprionodon longurio) 6.9% y el tiburón martillo común (Sphyrna lewini) 6.1%. A su vez, la raya látigo (D. longa) y el tiburón picudo fucsia (Nasolamia velox) representaron un 3.5% y 2.6% de la captura total, respectivamente. En los 75 viajes a bordo se capturó un total de 6.458 peces, de los cuales solo el 4.4% (240 individuos) fueron tiburones y rayas látigo. M. henlei fue nuevamente la especie más abundante (50.4%), le siguieron R. longurio (21.7%), D. longa (13.8), N. velox (5.8%), S. lewini (5.8%), y por último, M. lunulatus (2.5%). Debido a la estacionalidad y abundancia de tiburones mamones en la zona de Herradura, se recomienda un cierre técnico en enero-febrero y setiembre-octubre, meses con las mayores capturas. También se recomienda la protección de la zona del Peñón, ya que es utilizada por la raya látigo y por los juveniles del tiburón martillo. &nbsp;From February 2006 to February 2007, we analyzed shark and rays captures by the artisanal fishermen from Tárcoles, in the Pacific of Costa Rica. We observed 415 fishing operations (bottom line, gillnet and ray line): 340 dock landing observations and 75 (18.1%) on board observations. During the landing observations, we analyzed 3299 sharks and rays: the brown smooth hound (Mustelus henlei) was the most common species (63.7%), followed by the common smooth hound (Mustelus lunulatus) (16.7%), the Pacific sharpnose shark (Rhizoprionodon longurio) (6.9%) and the scalloped hammerhead shark (Sphyrna lewini) (6.1%). The longtail stingray (Dasyatis longa) and the whitenose shark (Nasolamia velox) represented the 3.5% and 2.6% of the total catch, respectively.&nbsp; During 75 fishing trips, we analyzed 6.458 fish individuals, of them only 4.4% (240 individuals) were sharks and longtail stingrays. Among these, M. henlei was also the most abundant species (50.4%), followed by R. longurio (21.7%), D. longa (13.8%), N. velox (5.8%), S. lewini (5.8%), and M. lunulatus (2.5%). Considering the seasonality and abundance of smooth hound sharks in Herradura, we recommend a technical closure during the higher catch months (January-February and September-October). Also, we recommend protecting the Peñón, which is inhabited by adults of longtail stingray and juvenile scalloped hammerhead sharks.Analizaram-se as capturas de tubarões e raia ratão realizadas por pescadores artesanais de Tárcoles no Pacífico da Costa Rica, desde fevereiro de 2006 até fevereiro de 2007. Observaram-se 415 fainas de pesca (linha de fundo, tresmalho e linha de raia): 340 corresponderam a observações de descarga e 75 (18.1%) a observações a bordo. Durante as descargas analizaram-se 3.299 tubarões e raias ratão: o tubarão mamón enano (Mustelus henlei) dominou na captura total (63.7%), seguido pelo tubarão mamão común (Mustelus lunulatus) (16.7%), o cação-frango (Rhizoprionodon longurio) (6.9%) e o tubarão-martelo-recortado (Sphyrna lewini) (6.1%). Por sua vez, a raia ratão (D. longa) e o tubarão picudo fucsia (Nasolamia velox) representaram 3.5% e 2.6% da captura total, respectivamente. Nas 75 viagens a bordo capturou-se um total de 6.458 peixes, dos quais somente 4.4% (240 indivíduos) foram tubarões e raias ratão. M. henlei foi novamente a espécie mais abundante (50.4%), seguido por R. longurio (21.7%), D. longa (13.8), N. velox (5.8%), S. lewini (5.8%), e por último, M. lunulatus (2.5%). Devido à estacionalidade e abundância de tubarões mamones na zona de Herradura, recomenda-se um fechamento técnico em janeiro-fevereiro e setembro-outubro, meses com as maiores capturas. Também se recomenda a proteção da zona do Peñón, já que é utilizada pela raia ratão e pelos tubarão-martelo jovens.&nbsp

Abundance, size and population structure of whitetip reef sharks, Triaenodon obesus (Carcharhiniformes: Carcharhinidae), in Bahia Chatham, Parque Nacional Isla del Coco, Costa Rica.

Approximately 12 species of shark inhabit at Coco Island National Park (PNIC); some are migratory, such as the hammerhead shark (Sphyrna lewini) and whale shark (Rincodon typus), and others are resident, like the whitetip shark (Triaenodon obesus). The whitetip shark is a species related to coral reefs, it inhabits coastal environments and is nocturnal and, it is very common in tropical waters, but there are few studies worldwide. In fact, only short researches have been done about their behavior at PNIC. Therefore, this study aimed to give data about the abundance, size and population structure of the whitetip shark at Chatham Bay in Coco Island National Park, providing baseline information for monitoring its population which is also very vulnerable to climate change. In order to accomplish this aim, a mark-recapture method was used, as well as underwater visual counts to determine their relative abundance and visual recaptures at Chatham Bay. The most effective hours for tagging were between 18:00 and 22:00 (sunset), when the whitetip sharks were more active probably related to foraging behavior. In addition, the depth was a relevant factor for tagging, sharks were caught in shallow water (10.9±1.9m). This species prefers to feed in shallow water and this behavior is probably related to the distribution and occurrence of rock and coral reefs in Chatham Bay. Based on the results, whitetip shark do not have a defined spatial ontogenic segregation, since in the same sites both juveniles and adults were found. The study confirmed that whitetip shark use specific residence sites: during the tagging trips, different individuals were recaptured; and during the underwater counts, at least 32.76% of tagged sharks were observed. The average length of the tagged sharks was 101.8±12.1cm (130.0cm maximum and 71.0cm minimum). The relative abundance of the whitetip shark in Chatham Bay observed was estimated on 49.5±10.4 sharks/hour. Furthermore, using the recapture data obtained during the night tagging expeditions, a population of 408 (IC = 181-1050) sharks was estimatedUniversidad Nacional, Costa RicaInstituto Internacional en Conservación y Manejo de Vida Silvestr

Análisis de las capturas de tiburones y rayas en las pesquerías artesanales de Tárcoles, Pacífico Central de Costa Rica

Se analizaron las capturas de tiburones y rayas látigo realizadas por pescadores artesanales de Tárcoles  en el Pacífico de Costa Rica, desde febrero del 2006 hasta febrero del 2007. Se observaron 415 faenas de pesca (línea de fondo, trasmallo y línea rayera): 340 correspondieron a observaciones de descarga y 75 (18.1%) a observaciones a bordo. Durante las descargas se analizaron 3299 tiburones y rayas látigo: el tiburón mamón enano (Mustelus henlei) dominó en la captura total (63.7%), seguido por el tiburón mamón común (Mustelus lunulatus) (16.7%), el tiburón picudo común (Rhizoprionodon longurio) 6.9% y el tiburón martillo común (Sphyrna lewini) 6.1%. A su vez, la raya látigo (D. longa) y el tiburón picudo fucsia (Nasolamia velox) representaron un 3.5% y 2.6% de la captura total, respectivamente. En los 75 viajes a bordo se capturó un total de 6.458 peces, de los cuales solo el 4.4% (240 individuos) fueron tiburones y rayas látigo. M. henlei fue nuevamente la especie más abundante (50.4%), le siguieron R. longurio (21.7%), D. longa (13.8), N. velox (5.8%), S. lewini (5.8%), y por último, M. lunulatus (2.5%). Debido a la estacionalidad y abundancia de tiburones mamones en la zona de Herradura, se recomienda un cierre técnico en enero-febrero y setiembre-octubre, meses con las mayores capturas. También se recomienda la protección de la zona del Peñón, ya que es utilizada por la raya látigo y por los juveniles del tiburón martillo.From February 2006 to February 2007, we analyzed shark and rays captures by the artisanal fishermen from Tárcoles, in the Pacific of Costa Rica. We observed 415 fishing operations (bottom line, gillnet and ray line): 340 dock landing observations and 75 (18.1%) on board observations. During the landing observations, we analyzed 3299 sharks and rays: the brown smooth hound (Mustelus henlei) was the most common species (63.7%), followed by the common smooth hound (Mustelus lunulatus) (16.7%), the Pacific sharpnose shark (Rhizoprionodon longurio) (6.9%) and the scalloped hammerhead shark (Sphyrna lewini) (6.1%). The longtail stingray (Dasyatis longa) and the whitenose shark (Nasolamia velox) represented the 3.5% and 2.6% of the total catch, respectively.  During 75 fishing trips, we analyzed 6.458 fish individuals, of them only 4.4% (240 individuals) were sharks and longtail stingrays. Among these, M. henlei was also the most abundant species (50.4%), followed by R. longurio (21.7%), D. longa (13.8%), N. velox (5.8%), S. lewini (5.8%), and M. lunulatus (2.5%). Considering the seasonality and abundance of smooth hound sharks in Herradura, we recommend a technical closure during the higher catch months (January-February and September-October). Also, we recommend protecting the Peñón, which is inhabited by adults of longtail stingray and juvenile scalloped hammerhead sharks.