Sponge aquaculture for the production of biologically active metabolites: the influence of farming protocols and environment

Before sponge aquaculture is accepted as a commercially viable method of supplying bioactive metabolites, it must be demonstrated that adequate production of sponge biomass and metabolite is possible. In this study, we fanned the New Zealand Demospongiae Latrunculia wellingtonensis (Alvarez, Bergquist and Battershill) and Polymastia croceus (Kelly-Borges and Bergquist) for 9 months at two nearby locations with differing flow rates using two fanning methods: rope lines and suspended mesh arrays. The fanned explants were harvested at regular intervals over the 9 months by cutting and removing new biomass, leaving behind the original explant "core" to heal and regrow. For both species, explants grew as water temperature increased and shrunk as water temperature fell, and growth was greatest overall at the location with the greatest flow rate. Some treatments exhibited remarkable sponge growth (up to 960% in 6 months), with overall biomass yields double or greater the initial transplanted weight. Growth after harvesting was similar between harvested and nonharvested explants, indicating that healing of cut biomass and reorganization of the canal system is not a significant drain on resources. Bioactivity of fanned sponges (measure of bioactive metabolite biosynthesis) was similar or greater than found in natural populations. Both rope and mesh arrays were found to be good farming structures, but differing patterns of growth and survival indicated that the two arrays are most suited for a particular type of sponge depending on its skeletal structure. (C) 2003 Elsevier Science B.V. All rights reserved.