Temporal and spatial patterns in the distribution of squid Loligo spp. in United Kingdom waters

A Geographic Information System (GIS) was used to test hypotheses regarding the spatial distribution of the squid Loligo forbesi and Loligo vulgaris vulgaris in the northern North-East Atlantic during the years 1989-1994. Loligo spp. were present throughout coastal waters of the United Kingdom, but distribution was patchy and highly variable over space and time. The relationship between squid distribution and sea temperature and salinity in the North Sea was examined by overlaying maps of squid abundance (landings per unit effort, lpue) and oceanographic variables, and using correlation and multiple regression analysis. Bottom temperature was most frequently correlated with lpue, with correlations between squid and oceanographic parameters occurring most often in January and February of a given year. Monthly changes in distribution patterns are consistent with squid undertaking seasonal migrations around the coast of the U.K. It is at present unknown whether temperature and salinity influence squid distribution directly (e.g. reflecting physiological tolerence limits) or through effects on recruitment, growth or mortality, or indirectly as a result of passive movement of squid into the North Sea during inflow of warmer Atlantic water.