Survival of non-commercial size Patagonian scallop discarded by the fishery

The most important benthic fishery in extension and production of the Southwest Atlantic is that of Patagonian scallop (Zygochlamys patagonica). It is exploited by four factory vessels with non-selective bottom trawl nets and processing plant on board. During the selection process the scallops of commercial size (≥ 55 mm total high) are retained and those that do not reach it (< 55 mm TH) are discarded back to the sea. The purpose of this work was to determine the survival level of non-commercial specimens discarded to the sea and the effect of the selection process on board. Non-commercial scallops coming from deck (control) and discard (treatment) were selected. They were classified according to the level of damage and placed in polypropylene bags to be anchored (~ 100 m depth). The bags were retrieved 10 and 54 d after and the amount of live specimens in each one was registered. The highest survival level was observed in individuals without damage or damaged only on the edges; in those with breaks or perforations in the shell the percentage rounded 50%. It was observed that survival decreased as the time of the experiment increased.