MEPS 310:25-32 (2006)  -  doi:10.3354/meps310025

ABSTRACT: The Jumbo flying squid Dosidicus gigas has a short life span and is subject to rapid changes in population size. This species inhabits the Eastern Pacific, one of the most variable oceanic environments in the world, subject to the El Niño Southern Oscillation (ENSO). This study examined the influence of environmental variability on squid abundance off Peru using mesoscale oceanographic indicators derived from remotely sensed satellite imagery. In the fishery area off Peru, squid abundance was positively associated with sea surface temperatures (SST) between 17 and 22°C during July, corresponding to the peak of the fishery season. In the putative hatching area close to the Costa Rica Dome, squid abundance was positively associated with SST of between 24 and 28°C during September, prior to the start of the fishery season. Squid abundance is apparently strongly influenced by mesoscale variability linked to ENSO, with low levels of upwelling during the very strong El Niño of 1997 to 1998 leading to very low catches of squid off Peru. Variability in upwelling off Peru and in the Costa Rica Dome region may drive primary and secondary production and transport processes affecting the planktonic early life stages and also the availability of food and suitable habitat for adult squid.

KEY WORDS: Costa Rica Dome · Dosidicus gigas · El Niño Southern Oscillation · Eastern Pacific · Fishery · Flying squid · Mesoscale oceanography · Upwelling