Volumen 46 - Número 3 - 405-419

RBMO 46(3): 405-419 \| 2011 Article	PDF
Eggs and larvae of anchoveta Engraulis ringens off northern Chile during the 1997-1998 El Niño event
Pablo M. Rojas^1*, Mauricio F. Landaeta² & Raúl Ulloa³
¹División de Investigación en Acuicultura, Instituto de Fomento Pesquero (IFOP), Balmaceda 252, Casilla 665, Puerto Montt, Chile ²Laboratorio de Ictioplancton (LABITI), Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, Casilla 5080, Viña del Mar, Chile ³Universidad Autónoma de Nayarit, Postgrado Ciencias Biológicas Agropecuarias y Pesqueras, Ciudad de la Cultura Amado Nervo, CP 63000, Tepic, Nayarit, México *Esta dirección de correo electrónico está siendo protegida contra los robots de spam. Necesita tener JavaScript habilitado para poder verlo.
The impact of the El Niño event (1997-1998) on the spatial dynamics as well as on the changes in the aggregation patterns of anchoveta eggs and larvae due to the alteration in the thermal anomalies were analyzed. Six bio-oceanographic surveys were carried out in northern Chile from Arica (18°29'S, 70°19'W) to Antofagasta (23°38'S, 70°24'W) over different periods (before and during) of the 1997-1998 El Niño event. Changes in the vertical distribution and aggregation patterns of anchoveta in early life stages were registered as well as an increase in zooplankton biomass with the arrival of El Niño; moreover, the spatial distribution of anchoveta was altered due to the gradually poleward displacement of spawning areas as a result of the arrival of subtropical warm waters from the north. The increase in zooplankton biomass linked to a change in the species composition suggests a negative impact on the anchoveta larval feeding. Our results suggest that abrupt changes in the environment would have immediate consequences on the spatial distribution of anchoveta in early life stages, causing a potential impact on the recruitment of this small pelagic fish in the Humboldt Current System off northern Chile.
Key words: Chile-Humboldt Current System, fish larvae, thermal anomaly, coastal upwelling, zooplankton
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