Preliminary study of discard composition in a surface pair trawls and botton trawls fisheries at Puerto Quequén (Buenos Aires Province, Argentina).

CHIARAMONTE, G.; TAMINI, L. L.; PEREZ, J. E.; ARRIBALZAGA, M.E.; CAPPOZZO, H.L

Montpelier, Francia

Simposio; ICES / SCOR Ecosystem effects of fishing.; 1999

International Council for the Exploration of Sea (ICES) and Scientific Commitee on Oceanic Res

Over 730 vessels compose the fishing fleet in Argentina. Coastal vessels are 439 while 42 are working at Puerto Quequén (38° 37'S, 58°50'W). Four kinds of gears are used in the area: bottom trawls (BT), surface pair trawls (SPT), bottom gillnets and purse seine. This report describes the discard composition of the SPT and BT fisheries. During 1998 autumn-winter seasons discard in both kind of fisheries where studied by on-board observers. Nineteen gear operations were analysed. The fishing discard was composed by several species of invertebrates, elasmobranchs, finfishes, and sea birds. Each catch was identified at species level (when possible), and weighted and measured at laboratory. The target species in the SPT was the “cornalito” (Sorgentinia incisa) while BT fishery was multispecific. In SPT, 33 % of total biomass of discard was composed by five species of finfishes (Odonthestes sp.; Pomatomus saltatrix; Parona signata; Engraulis anchoita and Lycengraulis grossidens) and 67 % of discard was Magellan penguin (Spheniscus magellanicus). In BT, 57.93 % of elasmobranchs and 42.07 % of finfishes composed fish biomass discard. SPT total discard was 2.3 % of total landing biomass while in BT was 80.17 %. The impact on the marine ecosystem was different between both kinds of fisheries: SPT appears as low associated discard with few species but could be important in marine birds while BT reveals an important impact on different taxa and its effect on benthonic communities was not measured yet.