Influence of the ENSO cycle on the light-fishery for Dosidicus gigas in the Peru Current: an analysis of remotely sensed data

Dosidicus gigas (the jumbo flying squid) supports a major fishery in the eastern Pacific Ocean and exhibits large fluctuations in abundance from year to year. The commercial fishery consists of a multinational jigging fleet and the emission of light from these vessels can be observed using satellite-derived imagery obtained by the United States Defence Meteorological Satellite Program-Operational Linescan System (DMSP-OLS). Fishery abundance and fleet distribution were examined in Peruvian waters during years of intermediate (1994), La Niña (1996), and El Niño (1997) conditions, and compared with catch data from other parts of the species range (to the north and south of Peru). Squid catches off Peru were highest under intermediate conditions, with lower catch levels recorded during periods of cool or warm temperature anomalies. The fishery was distributed between 3° and 16°S in both coastal and high seas waters, over depths of greater than 1000 m. Unusually cool or warm conditions may cause a reduction in the abundance of squid off the coast of Peru, with catches increasing in other parts of the species range, notably off the coast of Central America (close to the Costa Rica Dome) and in the Gulf of California, Mexico. Squid fishing took place in waters with sea surface temperatures (SSTs) between 17 and 22 °C, but SST was not directly associated with fleet distribution. It is likely that variability in upwelling strength and the occurrence of cool core mesoscale oceanographic features are important in influencing the distribution of D. gigas in Peruvian waters.

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