ABSTRACT
Introducción: En los ambientes marinos del Pacífico de Costa Rica, la actividad pesquera por la flota cerquera internacional es importante debido a su amplio alcance y fuerte impacto. Objetivo: Evaluar la distribución espacial de la captura de atún aleta amarilla y especies no objetivo por esa flota, y posibles correlaciones con variables ambientales y pesqueras. Métodos: Aplicamos estadísticas geoespaciales y modelos de regresión múltiple en datos de la Comisión Interamericana del Atún Tropical, del 2002 al 2011. Utilizamos una grilla del tamaño de la Zona Económica Exclusiva (ZEE) con 1 124 celdas de 22 x 22 km (unidad de análisis), para un total de 11 240 celdas-año. Resultados: El atún mediano (presumiblemente inmaduro en su mayoría), delfines, mantas y rayas fueron capturados mayormente dentro del Domo Térmico (noreste de la ZEE). Las más altas capturas de atún pequeño (inmaduro en su totalidad), tiburones, picudos, dorado, peto y diversas especies pequeñas, ocurrieron en el extremo sur. El atún grande (maduro) fue capturado especialmente en el centro de la ZEE, hacia el este del Área Marina de Manejo Montes Submarinos y el Parque Nacional Marino Isla del Coco. Los atunes, dorado, delfines, mantas y rayas mostraron gran fidelidad de sitio por asociación con variables geográficas y ambientales, a la vez que el atún pequeño estuvo asociado a lances sobre objetos flotantes y el atún grande a lances sobre delfines. La heterogeneidad de las especies no objetivo probablemente escondió la mayoría de las correlaciones. Conclusiones: La pesca está afectando los niveles tróficos más altos y es necesario un diseño de zonificación ajustado para proteger mejor el domo térmico y considerar la susceptibilidad al uso de redes de cerco.
Introduction: In the Pacific marine ecosystems of Costa Rica, fishing activity by the international purse-seine fleet is important for its wide scope and large impact. Objective: To evaluate the spatial distribution of the catch of yellowfin tuna and non-target species by this fleet, and possible correlates with environmental and fishing variables. Methods: We applied geospatial statistics and multiple regression models to Inter-American Tropical Tuna Commission data, covering from 2002 to 2011. We used a grid the size of the Exclusive Economic Zone (EEZ) with 1 124 cells of 22 x 22 km (unit of analysis), for a total of 11 240 year-cells. Results: The medium tuna (presumably immature for the most part), dolphins, mantas and rays dominated catches within the Thermal Dome (Northeast of the EEZ). Small tuna (all immature), sharks, billfishes, dorado, wahoo, and various small species were caught mostly in the extreme South. Large tuna (mature) was caught specially in the zone center, towards the east of the Submarine Mounts Marine Management Area and the Isla del Coco National Marine Park. Tuna, dorado, dolphins, mantas and rays showed high site fidelity due to their association with geographic and environmental variables, at the time small tuna was associated with sets on floating objects, and big tuna was associated with sets on dolphins. The heterogeneity of non-target species probably hid most correlations. Conclusions: Fishing is affecting the highest trophic levels and an adjusted zoning design is needed to better protect the thermal dome and to take into account susceptibility to the use of purse seines.
Subject(s)
Animals , Tuna , Perciformes/growth & development , Fishing Industry , Zoning , Costa Rica , FishesABSTRACT
Comparisons between the implications of commercial and recreational fisheries for estuarine conservation have been a topic of debate. A review on the available data from Guaratuba Bay, Southern Brazil, identifies six threats for conservation, other than those concerning the fishing effort on target resources. Differing from the popular view that fishing for pleasure could be innocuous for the environment, the identified threats concern both commercial and non-commercial fisheries: (1) catching of reproductive individuals; (2) catch of big old fat fecund females; (3) loss and abandonment of fishing gears; (4) use of natural baits; (5) bycatch of rays, turtles and non-target finfish; and (6) bad practices associated with catch-and-release or discarding. Environmental disturbances and fauna depletion are detected as potential impacts. Recommended actions for estuary conservation include fishing closures in mangrove and shallow waters areas, release of fish larger than the critical size, and measures against abandoned, lost or otherwise discarded fishing gears.
As implicações das pescas comercial e recreativa para conservação dos estuários têm sido largamente discutidas. Uma revisão das informações disponíveis para a Baía de Guaratuba, sul do Brasil, identifica seis ameaças à conservação, que extrapolam aquelas concernentes ao esforço de captura sobre as espécies-alvo. Contrariando a visão comum de que a pesca de lazer seria inócua para o ambiente, as ameaças identificadas referem-se tanto à pesca comercial como à não-comercial: (1) captura de indivíduos em atividade reprodutiva; (2) captura de fêmeas grandes e mais fecundas; (3) perda e abandono de materiais de pesca; (4) uso de iscas naturais; (5) captura incidental de raias, tartarugas e peixes não-alvo; e (6) práticas inadequadas associadas a pesque-e-solte e descarte. Impactos potenciais são perturbações ambientais e depleção de fauna. Ações recomendadas para conservação do estuário incluem interdição de pesca no manguezal e áreas rasas, soltura de peixes com tamanho superior ao crítico, e medidas contra abandono, perda e outras formas de descarte de materiais de pesca.
Subject(s)
Animals , Female , Turtles , Conservation of Natural Resources , Fisheries , Brazil , BaysABSTRACT
Abstract Comparisons between the implications of commercial and recreational fisheries for estuarine conservation have been a topic of debate. A review on the available data from Guaratuba Bay, Southern Brazil, identifies six threats for conservation, other than those concerning the fishing effort on target resources. Differing from the popular view that fishing for pleasure could be innocuous for the environment, the identified threats concern both commercial and non-commercial fisheries: (1) catching of reproductive individuals; (2) catch of big old fat fecund females; (3) loss and abandonment of fishing gears; (4) use of natural baits; (5) bycatch of rays, turtles and non-target finfish; and (6) bad practices associated with catch-and-release or discarding. Environmental disturbances and fauna depletion are detected as potential impacts. Recommended actions for estuary conservation include fishing closures in mangrove and shallow waters areas, release of fish larger than the critical size, and measures against abandoned, lost or otherwise discarded fishing gears.
Resumo As implicações das pescas comercial e recreativa para conservação dos estuários têm sido largamente discutidas. Uma revisão das informações disponíveis para a Baía de Guaratuba, sul do Brasil, identifica seis ameaças à conservação, que extrapolam aquelas concernentes ao esforço de captura sobre as espécies-alvo. Contrariando a visão comum de que a pesca de lazer seria inócua para o ambiente, as ameaças identificadas referem-se tanto à pesca comercial como à não-comercial: (1) captura de indivíduos em atividade reprodutiva; (2) captura de fêmeas grandes e mais fecundas; (3) perda e abandono de materiais de pesca; (4) uso de iscas naturais; (5) captura incidental de raias, tartarugas e peixes não-alvo; e (6) práticas inadequadas associadas a pesque-e-solte e descarte. Impactos potenciais são perturbações ambientais e depleção de fauna. Ações recomendadas para conservação do estuário incluem interdição de pesca no manguezal e áreas rasas, soltura de peixes com tamanho superior ao crítico, e medidas contra abandono, perda e outras formas de descarte de materiais de pesca.
ABSTRACT
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.
ABSTRACT
This study provides the first data on the population structure of swimming crab Callinectes ornatus Ordway, 1863 bycatch from coastal shrimp fishing in northern Rio de Janeiro State, Brazil (21º 30'-21º 50' S and 41º 05'-41º 07' W). Crabs were collected monthly from April 2006 to March 2007. A total of 5,611 specimens were analyzed, of which 3,951 were males and 1,660 ovigerous and non-ovigerous females. The overall sex ratio (2:1) differ significantly from the expected 1:1 proportion, being the mature males significantly predominant as bycatch in this fishery. The specimens' carapace width and weight varied from 27 to 126 mm (mean: 77.3 ± 12.3 mm) and 1.2 to 128.2 g (mean: 31.0 ± 14.4 g) for males, and 30 to 101 mm (mean: 63.4 ± 9.3 mm) and 1.7 to 66.0 g (mean: 16.4 ± 7.4 g) for ovigerous and non-ovigerous females. Seasonal comparisons did not reveal differences between the number of specimens captured in dry and rainy periods considering both sexes and maturity stages. The size at first maturity was 79 mm for males and 65 mm for females, and the carapace width-weight relationship indicated an alometric pattern for both sexes. The bycatch swimming crabs are locally used as bait, but the capture tendency for a specific sex/age-group can affect this population structure over time.
Este estudo fornece os primeiros dados sobre a estrutura populacional do siri Callinectes ornatus Ordway, 1863 capturado incidentalmente através da pesca camaroneira realizada no litoral norte do estado do Rio de Janeiro, Brasil (21º 30'-21º50' S e 41º 05'-41º 07' O). Os siris foram coletados mensalmente entre abril de 2006 a março de 2007. Um total de 5.611 espécimes foram analisados, dos quais 3.951 eram do sexo masculino e 1.660 fêmeas ovígeras e não ovígeras. A razão sexual (2:1) diferiu significativamente da proporção 1:1 esperada, sendo os machos maduros significativamente predominantes como captura incidental nesta pescaria. A largura da carapaça e o peso dos espécimes variaram de 27 a 126 mm (média: 77,3 ± 12,3 mm) e 1,2 a 128,2 g (média: 31,0 ± 14,4 g ) para machos, e 30 a 101 mm (média: 63,4 ± 9,3 mm ) e 1,7 a 66,0 g (média: 16,4 ± 7,4 g) para fêmeas ovígeras e não ovígeras. As comparações sazonais não revelaram diferenças entre o número de espécimes capturados nos períodos seco e chuvoso, considerando ambos os sexos e estágios de maturidade. O tamanho de primeira maturação foi de 79 mm para machos e 65 mm para as fêmeas, e a relação largura da carapaça-peso indicou padrão alométrico para ambos os sexos. Os siris capturados incidentalmente são utilizados localmente como isca, mas a tendência de captura sobre um grupo sexual/etário específico pode afetar a estrutura dessa população ao longo do tempo.
ABSTRACT
Longfin sanddab (Citharichthys xanthostigma) represents a very important fishery resource in Southern and Baja California but are not very well known. The purpose of this study is to provide information on the growth and mortality of longfin sanddab population in the Mexican Pacific Ocean at Baja California, México. Data on growth were obtained for longfin sanddab collected with otter trawls during six cruises off the Western coast of Baja California. A total of 1 017 longfin sanddab were caught over the sampling period, and from 860 specimens, the male to female ratio was 1:1.8. The relationship between total weight (W) and standard length (SL) is described: W=0.00000743 SL3.196 for females and W=0.00000764 SL3.193 for males. Age groups were estimated from length frequency data, and von Bertalanffy annual growth parameters for all fish data combined were the following: L∞=289.2mm SL, k=0.20, t0=-0.73; for males, they were L∞=265.9mm SL, k=0.21, t0=-0.68, and for females, L∞=293.6mm SL, k=0.23, t0=-0.35. Longfin sanddab caught during this study reached a maximum age of 10 years, and at that age, males attained smaller sizes than females. The age groups had a total mortality (Z) rate of 0.82 year-1, a fishing mortality (F) of 0.52 year-1, and a natural mortality (M) of 0.3 year-1. Although the longfin sanddab is not a target species of commercial fisheries, it suffers high mortality as part of the bycatch in the shrimp fishery. Rev. Biol. Trop. 58 (2): 689-705. Epub 2010 June 02.
Se presenta información sobre el crecimiento y mortalidad de la población del C. xanthostigma (lenguado alón) en el Pacífico Mexicano de Baja California, México. Datos sobre su crecimiento fueron obtenidos de peces capturados con red de arrastre durante seis cruceros en la costa Oeste de Baja California, México. Se capturaron 1 017 peces en este periodo. La relación machos:hembras de 860 ejemplares fue de 1:1.2. La relación peso total (W) y longitud estándar (SL) se estimó para hembras: W=0.00000743 SL 3.196 y para machos: W=0.00000764 SL 3.193. La edad de los grupos se calculó con datos de frecuencia por longitud, el crecimiento de von Bertalanffy global fue: L∞=289.2mm SL, k=0.20, t0= -0.73; para los machos: L∞=265.9 mm SL, k=0.21, t0= -0.68 y para las hembras: L∞=293.6mm SL, k=0.23, t0=-0.35, anualmente. La captura de C. xanthostigma durante este estudio alcanzó una edad máxima de 10 años. Los machos alcanzan tallas menores que las hembras a la misma edad. Los grupos de edad tuvieron una tasa de mortalidad total (Z) de 0.82 por año, una mortalidad por pesca (F) de 0.52 por año y mortalidad natural (M) de 0.3 por año. Aunque el C. xanthostigma no es una especie objetivo (comercial), sufre una alta mortalidad indirecta durante la pesca del camarón.
Subject(s)
Animals , Female , Male , Flatfishes/growth & development , Longevity , Mortality , Flatfishes/anatomy & histology , Flatfishes/classification , Mexico , Seasons , SeawaterABSTRACT
Objetivo. El presente estudio evalúa las capturas ícticas incidentales de la pesca de especies ornamentales, en términos de abundancia y riqueza, en la zona de influencia del municipio de Puerto Carreño, Vichada, Colombia. Materiales y métodos. Para esto, se realizaron muestreos en los ríos Bita, Orinoco y en Caño Negro, durante el período de aguas bajas, en marzo y abril de 2007. A partir del acompañamiento realizado a las jornadas de pesca ornamental, se colectaron 152 especies entre incidentales y objeto. Se estimó la captura por unidad de esfuerzo (CPUE) y la composición porcentual de las capturas ícticas de las especies objeto versus las incidentales. Resultados. Los valores más altos de CPUE para especies objeto corresponden a los estimados para: Dicrossus maculatus, Hemigrammus rodhostomus, Corydoras cf. melanistius, Peckoltia sp. 2. y Hemiancistrus sp.; Por otro lado, los valores más altos para las especies ícticas incidentales corresponden a: Hemigrammus sp., Moenkhausia sp., Hemigrammus levis, Aphanothorulus cf. ammophilus, Triportheus angulatus y Moenkhausia lepidura. El porcentaje en riqueza para las especies ícticas incidentales varió entre el 92% y 98%. No obstante, el porcentaje en abundancia de las especies objeto fue mayor que el obtenido para las capturas incidentales variando entre 73% y 83%, con excepción de la obtenida en la pesca en los afloramientos rocosos del río Orinoco que fue del 17%. Conclusiones. El impacto de la pesca ornamental sobre las especies de peces capturadas incidentalmente se observa principalmente a nivel de riqueza, pero no a nivel de abundancia.
Objective. The present study assesses the incidental fish catches in the fishing of ornamental species in terms of richness and abundance within the influence zone of Puerto Carreño, Vichada, Colombia. Materials and methods. Samplings were carried out in the Orinoco River and Bita River and Caño Negro stream during the low-water season, in March and April of 2007. Target and incidental species collected during the ornamental fishing totalized 152. Catches per unit of effort (CPUE) as well as the percentage composition of fish catches of target vs. incidental species were estimated. Results. The highest values of CPUE of fishes with ornamental value correspond to: Dicrossus maculatus, Hemigrammus rodhostomus, Corydoras cf. melanistius, Peckoltia sp. 2 and Hemiancistrus sp., and the highest values of incidental species were for: Hemigrammus sp., Moenkhausia sp., Hemigrammus levis, Aphanothorulus cf. ammophilus, Triportheus sp. y Moenkhausia lepidura. The richness percentage of incidental species varied between 92% and 98%. However the abundance percentage of target species was always higher than the percentage of incidental catches varying between 73% and 83% with the exception of that obtained in the fisheries of the Orinoco River outcrops that was 17%. Conclusions. The impact of the fishing ornamental fish on species taught incidentally is seen mainly at the level of richness, but not at the level of abundance.
Objetivo. Este estudo avalia a captura incidental de peixes produto da pesca ornamental, em termos de abundância e riqueza, na bacia hidrográfica do município de Puerto Carreño, Vichada, Colômbia. Materiais e métodos. Para isso, realizaram-se amostragens nos rios Bita, Orinoco e Caño Negro, durante o período de níveis da água baixos, em Março e Abril de 2007. A partir do acompanhamento direto feito na pescaria ornamental, foram coletadas 152 espécies entre as alvo e as incidentais. Estimaram-se as capturas por unidade de esforço (CPUE) e a composição percentual das capturas das espécies-alvo versus as incidentais. Resultados. Os maiores valores de CPUE para as espécies-alvo correspondem aos estimados para: Dicrossus maculatus, Hemigrammus rodhostomus, Corydoras cf. melanistius, Peckoltia sp. 2 e Hemiancistrus sp., e os maiores valores para espécies incidentais correspondem a: Hemigrammus sp., Moenkhausia sp., Hemigrammus levis, Aphanothorulus cf. ammophilus, Triportheus angulatus e Moenkhausia lepidura. O percentual da riqueza das espécies de peixes incidentais variou entre 92% e 98%. No entanto, o percentual da abundância das espéciesalvo foi maior que aquele pra as espécies incidentais variando entre 73% e 83%, com exceção da obtida na pesca nos afloramentos rochosos do río Orinoco o qual foi de 17%. Conclusões. O impacto da pesca ornamental sobre as espécies de peixes capturadas incidentalmente pode ser observado principalmente ao nível de riqueza, mas não ao nível de abundância.
ABSTRACT
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.