Deciding the methodological approach for marine sponge rearing in an Integrated Multitrophic Aquaculture (IMTA) system

Polyculture of fish alongside other organisms at different levels of the food web (Integrated Multitrophic Aquaculture, IMTA) has considerable economic potential especially if, edible and/or non-edible, species with a potentially high commercial value are co-cultured. In the Remedia Life IMTA system, Dicentrarchus labrax and Sparus aurata fish cages were associated with an innovative set of bioremediating organisms such as sponges, polychaetes, bivalves and macroalgae. In order to evaluate the best method for sponge rearing and thus improve the cost-effectiveness of the system, different vertical culture systems were established and monitored for one year. Specimens of Sarcotragus spinosulus (Porifera, Demospongiae) were cut into explants of similar size (≈ 100 mL), arranged in rope, fishnet sock and net bag systems and monitored in terms of survival rate. All three methodologies induced a high survival rate of no less than 82%, which reached 93% when the net bag was used. Overall, the rearing methods tested promise great results when farming marine sponges in IMTA systems.