Species composition and bycatches of a new crustacean trawl in Chile

The species composition and bycatches of a new trawl for crustaceans (Heterocarpus reedi, Cervimunida johni and Pleuroncodes monodon) was studied in central Chile between 2007 and 2009. The spatial and temporal variations of the catch composition were analyzed using univariate and multivariate comparison techniques. In 289 trawl hauls, 72 taxa were recorded, with target species accounting for most of the catch, while the bycatch consisted mainly of Merluccius gayi, Hippoglossina macrops, Coelorinchus aconcagua, Epigonus crassicaudus and Platymera gaudichaudii. 14 species of elasmobranchs were identified, and at least one of these species was present in 50% of the hauls made. The classification and ordination methods showed the existence of three groups, each one associated with a target species, with no significant spatial and temporal effects. The information obtained in this study represents the basis for setting targets in order to reduce the bycatch captured by this trawl. The focused strategy on the most recurring and sensitive species for these fisheries is also discussed.

► To reduce the bycatch of a new trawl, species composition studies are required. ► A total of 72 taxa were recorded for crustaceans trawl fisheries in Chile. ► The target species were the highest fraction of the catches and total bycatch consisted mainly of five species. ► The bycatches were different for each target species, with no significant spatial and temporal effects.