The Value of By-Catch: Can We Use Commercial Species Stock Assessment Cruises for the Study of Non-Target Species? The Case of Sponges

The contribution of sponges to benthic communities in three areas of the Argentine continental shelf and slope (North, Central and South), between 34° and 55° S and between 47 and 551 m, is presented here. Sponges were recorded as components of the invertebrate by-catch in 51% of the studied sites (133 hauls). On average, sponges constituted 18.01% of the benthic community (47.91 kg/mn2, in terms of density), reaching more than 90% of the by-catch and more than 500 kg/mn2 at some particular sites. A total of 34 sponge taxa were recorded. Tedania spp., Clathria (C.) microxa and Callyspongidae (Siphonochalina fortis + Callyspongia sp.) were the only taxa shared among the three sampled areas. Sixty percent (60%) of the sponge species were recorded only at one or two sites.