A new contribution on spatial and seasonal variability of physico-chemical parameters of the Golfo San Jorge benthic system from autumn 2001 through summer to 2002 is presented. Temperature, salinity, density, oxygen content and chlorophyll-a in bottom water as well as concentration of total organic matter, total organic carbon, total nitrogen, total phosphorus, chlorophyll-a and phaeopigments in sediments were analysed. The origin and nutritional value of the deposited organic matter were also assessed. The results reflect the existence of: (1) a typical temperate water seasonal cycle; (2) a bimodal cycle in the phytoplanktonic production; and (3) seasonal variations in the chemical variables and in organic matter origin in sediments.
Three sectors which geographically correspond with those identified in previous studies were defined: (1) the inner area of the gulf; (2) the areas next to the north and south extremes; and (3) the coastal and south-east part.