Abstract

Jumbo squid (Dosidicus gigas) off central Chile (32°00'S-41°30'S) was estimated using data collected from July to November during 2005 and 2006 on board the commercial bottom trawl fleet, where D. gigas is part of the bycatch. A geostatistical approach was applied to estimate the jumbo squid biomass in Chilean hake (Merluccius gayi) fishing grounds, which reached almost 135,000 t in 2005 and 131,000 t in 2006. The consumption-biomass ratio and the diet composition from a jumbo squid predation study during 2005 and 2006 were used to estimate the consumption of Merluccius gayi by D. gigas between 2001 and 2006. Assuming a direct relationship between the biomass and the catch per unit effort,D. gigas biomass and its consumption were estimated for 2001 to 2004. We also consider that the predation of jumbo squid on Chilean hake played an important role in the biomass reduction of this species off central Chile.