Catch composition of the Dutch pelagic fleet in the Mauritanian Exclusive Economic Zone during the year 2003: results of the scientific observer program

This report describes the total catches of the Dutch pelagic fleet in the Mauritanian Exclusive Economic Zone during the year 2003. Data have been obtained by the 'Scientific Observer Program', which monitors the catch (both landings and discards) of the Dutch fishery for small pelagics in Mauritania. The Dutch pelagic fleet in Mauritania focuses mainly on the group of sardinella (Sardinella aurita and Sardinella maderensis). Additional target species are pilchard (Sardina pilchardus) and chub mackerel (Scomber japonicus). The landings by weight in 2003 consisted for 95% of these 4 species, S. aurita being the dominant species (58% of the landings). In the year 2003, 91.6% of the estimated total catch by weight has been landed and 8.4% was discarded, which is reasonably comparable to previous years (1999-2002). The total estimated catch of the Dutch fleet has remained about the same, approximately 170 thousand tons per year. The dominance of S. aurita in the total estimated catch has gradually diminished throughout the years 1999-2003. Pilchard (S. pilchardus) and chub mackerel (S. japonicus) gradually replaced the round sardinella in the catches of the Dutch fleet since 1999. As in previous years, the catch of round sardinella mainly took place during the summer from June to September and the pilchard S. pilchardus appeared to be the dominant species in wintertime. The number of observer days has reduced slightly throughout the period 1999-2003. Nevertheless, the sampling method, both for small pelagic species and by-catch of pelagic megafauna, has improved in quality and quantity, which resulted in high quality data. The extension of the observers’ dataset in 2003 with a fifth year in a row enlarged the possibilities to use this database for detailed research on the biology and ecology of small pelagic species in the Mauritanian Exclusive Economic Zone, which is therefore highly recommended to be performed in the near future