Spatial variability of jumbo flying squid (Dosidicus gigas) fishery related to remotely sensed SST and chlorophyll-a concentration (2004-2012)

Abstract

An analysis was performed on the spatial distribution of the industrial Jumbo flying squid fishery within and outside the Peruvian exclusive economic zone (EEZ) in relation to sea surface temperature (SST) and chlorophyll-a (Chl-a). The locations of vessels were derived from the satellite tracking system (SISESAT) of the Instituto del Mar del Perú. Monthly environmental information came from the MODIS sensor of 4km spatial resolution for the period 2004–2012.Fishing operations data were divided into three periods based on their distance to shore consequential to the fishing regulations from January 2004 to October 2010, November 2010 to December 2011 and 2012. During the first period, two monthly patterns of spatial distribution were identified; from January to July fishing was along the coast from Paita (05°S) to San Juan de Marcona (15° 22′S) and later it was more concentrated in the northern area between Chimbote and Paita from August to December. In the second period, fishing operations formed small concentrations and widely dispersed points of fishing as a result of fishing restrictions within 80 nautical miles introduced in November 2010. In 2012 the fleet was located outside the EEZ. The highest concentrations of the fleet were found between 30 and 90 nautical miles offshore.The highest concentrations of squid were located from Paita-Chimbote (05°–09°S) and Callao–San Juan de Marcona (12° 03′–15° 22′S). Fishing operations were conducted in a wide range of SST between 14.1° and 26.8°C, with the highest incidence in temperatures between 18.4 to 22°C and with a tendency to be located more frequently in areas with higher temperatures in recent years. Regarding chlorophyll-a, the fleet fished between chlorophyll-a concentrations of 0–9.5mg/m3 within the EEZ, and from 0.2 to 0.5mg/m3 outside the EEZ. Distribution patterns of the fleet in relation to anomalies of sea surface temperature in the area El Niño 1+2, with respect to latitude and cyclic monthly SST variability, were also observed.