Data/hora: 04/06/2024 00:55:46

Provedor de dados: | 20
País: | Belgium

Título:

Distribución, evaluación acustica y estructura poblacional de la anchoíta. Resultados de las campañas del año 1993

Anchovy distribution, acoustic assessment and population structure. Results from year 1993 surveys

Autores: | Hansen, J.E.; Madirolas, A.
Data: | 2007-10-20
Ano: | 1996
Palavras-chave: | Pelagic fisheries; Geographical distribution; Biomass; Mortality; Echo surveys; Stock assessment; Geographical distribution; Biomass; Stock assessment; Pelagic fisheries; Mortality; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_5659; Http://aims.fao.org/aos/agrovoc/c_4945.
Resumo: | Two pelagic surveys to study were carried out during 1993. Those surveys covered the regions inhabited by either the bonaerensis stock in october (34-41°S)and the patagonian stock in November - December (41-45°30'S). Pre-stratified random sampling designs, including two random steps to allocate the transects, were adopted to perform the acoustic sampling by echo integration. A midwater trawl net (9-16 m vertical opening, 10 mm mesh-sized codend)was used to collect fish samples. The biomass of the northern stock was acoustically estimated to be about 1,45 million tons, whereas that of the southern stock was almost 740,000 t. Young anchovies, up to two-year old, allow for most of theose abundance values within each stock. The arrays of individuals at the sea both by size were calculated. There is some information supporting the picture of no increasing in anchovy total consumption by hake, as well as no main changes in natural mortality estimates. Most probably, the current biomass value has to be related to either a low reproductive success or recruitment as it is usual within Engraulids.
Tipo: | Journal Contribution
Idioma: | Espanhol

Identificador:

Revista de Investigación y Desarrollo Pesquero, 10. p. 5-21

0325-6375

http://hdl.handle.net/1834/1955

Editor: | Mar del Plata:  Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP)