Annual estimates of the unobserved incidental kill of pantropical spotted dolphin (Stenella attenuata attenuata) calves in the tuna purse-seine fishery of the eastern tropical Pacific

We estimated the total number of pantropical spotted dolphin (Stenella attenuata) mothers killed without their calves (“calf deficit”) in all tuna purse-seine sets from 1973– 90 and 1996–2000 in the eastern tropical Pacific. Estimates were based on a tally of the mothers killed as reported by color pattern and gender, several color-pattern-based frequency tables, and a weaning model. Over the time series, there was a decrease in the calf deficit from approximately 2800 for the western-southern stock and 5000 in the northeastern stock to about 60 missing calves per year. The mean deficit per set decreased from approximately 1.5 missing calves per set in the mid-1970s to 0.01 per set in the late-1990s. Over the time series examined, from 75% to 95% of the lactating females killed were killed without a calf. Under the assumption that these orphaned calves did not survive without their mothers, this calf deficit represents an approximately 14% increase in the reported kill of calves, which is relatively constant across the years examined. Because the calf deficit as we have defined it is based on the kill of mothers, the total number of missing calves that we estimate is potentially an underestimate of the actual number killed. Further research on the mechanism by which separation of mother and calf occurs is required to obtain better estimates of the unobserved kill of dolphin calves in this fishery.

Incidental capture of loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) sea turtles by the pelagic longline fishery off southern Brazil

Incidental capture in fishing gear is one of the main sources of injury and mortality of juvenile and adult sea turtles (NRC, 1990; Lutcavage et al., 1997; Oravetz, 1999). Six out of the seven extant species of sea turtles — the leatherback (Dermochelys coriacea), the green turtle (Chelonia mydas), the loggerhead (Caretta caretta), the hawksbill (Eretmochelys imbricata), the olive ridley (Lepidochelys olivacea), and the Kemp’s ridley (Lepidochelys kempii) — are currently classified as endangered or critically endangered by the World Conservation Union (IUCN, formerly the International Union for Conservation of Nature and Natural Resources), which makes the assessment and reduction of incidental capture and mortality of these species in fisheries priority conservation issues (IUCN/Species Survival Commission, 1995).

Captura de tunídeos com vara e isca viva em Moçambique

Included in the project MONAP GCP-MOZ/006/SWE "Fishing development in inland and coastal waters in Mozambique", a tuna fishing experimental program was carried out in coastal waters of Mozambique, using a catching method with rods and live baits. In order to explore this method and demonstrate the collaboration needed, the present paper has been thought for those interested in an overview of the work to be carried out.

Algumas notas sobre a captura e o aproveitamento do tubarão

The abundance of sharks is notable in the waters of Mozambique but this species has never been the object of a dedicated fishing effort. However, in recent years, some fishing activities have been carried out essentially for capture. The present paper describes status and trends of shark fisheries, utilization and trade of sharks. It is based mainly on working notes made by Mr. Tsnetoshi Mihara, a FAO expert involved in the MONAP Project - Development of coastal and continental fisheries (FI -1).

Captura de camarāo de águas pouco profundas e condições ambientais no Banco de Sofala

The present study deals with the performance of shrimp in shallow waters in Sofala Bank presents both seasonal fluctuations as well as fluctuations year to year. These variations may be due to several reasons: abundance of shrimp, fishing effort, fishing techniques and environmental conditions such as the turbidity of the water, tides, temperature and salinity.

Avaliaçāo preliminar do estado da exploraçāo de Kapenta (Limnothrissa miodon, Boulenger 1906), em cahora bassa com base em dados históricos de captura e esforço de 1995-2000

The fishing of kapenta (Limnothrissa miodon, Boulenger 1906) on the Cahora Bassa Dam started around 1992, when considerable stocks of this species were discovered in the lake. The species is believed to have successful established in the Dam following a natural introduction through a downstream movement from Kariba dam where it was introduced in 1967/68. Fisheries statistics on the kapenta fishery have been collected since 1993 by the Ministry of Fisheries through the Provincial Offices for Fisheries Administration of Tete (SPAP - Tete) but only data from 1995 onward are available on the database of the Ministry of Fisheries and these are the data that was used for compiling the present report on which trends of fishing effort, catch and CPUE are analyzed. Catch and effort have increased with time, from a minimum of the 4 thousand metric tons for an annual fishing effort of 36 fishing rigs in 1995 to a maximum of 12 tons for a fishing effort of 135 rigs while CPUE followed a decreasing trend during the same period. Correlation analysis between catch and effort suggests that probably environmental factors may have influence on catch variation than the increase on fishing effort. Two models were applied for calculating MSY and FMSY resulting in two pairs of roof leading to two scenario of fisheries management. 10137 tons and a FMSY of 177 fishing rigs were computed using Schaefer model while 11690 tons and a FMSY of 278 were obtained using Fox model. Considering the differences between the two results and considering the fact that the two models have no differences in terms of precision and the fact that their determination coefficient are not different it is suggested, using the precautionary principle that result from Schaefer model be a adopted for fisheries management purpose.

Sustentabilidad de la Pesquería Artesanal del Río Bermejo.

Este trabajo es el resultado de la tesis de Maestría en Recursos Naturales y Medio Ambiente (Orientación Recursos Faunísticos), realizada por el autor en la Facultad de Ciencias Naturales de la Universidad Nacional de Salta y bajo la dirección del Dr. Sergio Gustavo Mosa. La pesca artesanal con fines comerciales es practicada en el sector salteño del Río Bermejo desde hace décadas, por pobladores de localidades ribereñas como Orán, Embarcación y Rivadavia Banda Sur, los cuales pescan hasta el límite Salta – Chaco, dependiendo de la época del año. Esta pesquería se desarrolló por más de 50 años fuera del marco de las normas legales vigentes en la provincia (Ley 5513), siendo una actividad marginal perseguida por la justicia, y mal vista por la opinión pública en general. Entre Julio de 2001 y Julio de 2003, la Cooperativa de Pescadores Artesanales “La Unión” fue habilitada como empresa pesquera comercial de tipo artesanal por la Secretaria de Medio Ambiente y Desarrollo Sustentable de Salta. El monitoreo de esta actividad fue efectuado por la Cátedra de Piscicultura y Pesquerías (IRNED) de la Facultad de Ciencias Naturales de la Universidad Nacional de Salta. Las reglamentaciones y regulaciones legales de esta actividad se tomaron originariamente bajo el principio de precaución ante la falta de conocimiento científico. A la luz de la nueva información colectada, algunas de ellas resultan contrarias al principio prioritario de la gestión pesquera, el cual propone: Obtener la mejor utilización posible del recurso en provecho de la comunidad, recordando que mejor utilización implica mayor captura, mejor precio, más ganancias y más empleo. La presente Tesis de Maestría demuestra la sustentabilidad de la pesquería artesanal en el Bermejo, tanto desde a) el punto de vista biológico, analizando las capturas en función de las normas y reglamentaciones legales vigentes y de la biología y hábitos reproductivos de cada especie, como desde b) el punto de vista económico, teniendo en cuenta la relación costo-beneficio y las posibles alternativas para optimizar la misma. Asimismo, formula una serie de recomendaciones destinadas a mejorar la gestión pesquera. Para las 4 especies más importantes de la pesquería: sábalo Prochilodus lineatus, surubí Pseudoplatystoma coruscans, dorado Salminus brasiliensis y bagre blanco Pimelodus albicans, a) los cupos asignados para la captura anual por especie no son alcanzados; b) las tallas mínimas de captura observadas superan las tallas mínimas de captura autorizadas; c) las tallas medias de captura se encuentran muy por encima de las tallas medias de madurez sexual; d) la captura exclusiva de ejemplares maduros para todas las especies prueba que el grueso del stock pesquero ha podido superar por lo menos un evento reproductivo antes de ser capturado; e) el actual período de veda resulta demasiado amplio por lo que uno de dos meses, de mediados de noviembre a mediados de enero resultaría biológicamente adecuado. En cuanto a la sustentabilidad económica de la actividad, cada unidad económica de pesca debe realizar entre 45 y 50 excursiones de pesca anuales para obtener rendimientos económicos equivalentes a un ingreso mensual de aproximadamente $ 1000. (PDF tiene 92 paginas.)