Multivariate analysis of the commercial fishery of the northwestern coast of Greece, 1964-1981

Abstract

      The fishery of the northwest coast of Greece is revie­wed for 1964-1981. The mean annual (1964-1981) total catch amounted 1692 tons. Fish accounted for 96.2% whereas the proportion of cephalopods and crustaceans was very low, 2.1% and 0.8% respectively. Pilchard (Sardina pilchardus) dominated the landings with a mean annual catch of 440.5 tons, or 26% of the grand total. Pickarel (Spicara sp.) and horse mackerel (Trachurus sp.) made up 26% and 18.4% of the grand total respectively. Landings were ana­lysed using complementary clustering and ordination te­chniques (multidimensional scaling). The analysis indicated that the composition of the catch changed greatly from 1964-1971 to 1972-1981. Two main groups were indicated by both techniques: 1) pickarel, anchovy, hake, blue-whit­ing, flatfish, bogue, salema and chub mackerel, which are characterized by an increase in the catches and relative proportions during 1972-1981 as compared to 1964-1971, and 2) red pandora, grey mullet, red and stripped mullet, pilchard, horse mackerel, crustaceans and cephalopods, which are characterized by a decline in the catches and the rela­tive percentages in 1972-1981 as compared to 1964-1971. It is rather probable that large-scale changes in the hydro­meteorology of the Mediterranean Sea, described by many authors, are rensponsible for this shift in the species com­position of the catch.