By-catch and discards of the european purse seine tuna

An update of by-catch and discards estimations by species groups is presented for the \nEuropean purse seine tuna fishery operating in the Atlantic Ocean for 2008 and 2009 with 13 \nand 19 observed trips, respectively. Total by-catch was derived from a stratification based on \nfishing mode (free school vs. log school), season (quarters) and spatial area. The raising \nprocedure was based on production i.e., landings of major commercial tunas proceeded by \ncanneries. Annual by-catch for 2008 and 2009 was estimated to be about 11,500 t and 11,000 t, \nrespectively, corresponding to a mean annual value of 142 t per 1,000 t and 119 t per 1,000 t of \nproduction, respectively. Tuna represents the major part of the by-catch, followed by fin fishes. \nBy-catch fate, main species length distribution for the most common species and silky shark sex \nratio are presented.