Assessing the feasibility of sponge aquaculture as a sustainable industry in The Bahamas

Sponge harvesting was a significant part of the Bahamian economy until the late 1930s when disease, hurricanes, and unsustainable harvesting practices reduced the viability of the sponge industry. Current international demands for natural products, increasing regional needs for economic diversification, and the historical foundation of sponging in The Bahamas makes sponge aquaculture a desirable candidate as a sustainable industry. To determine the feasibility of sponge aquaculture in The Bahamas, we deployed growout arrays between February 2006 and September 2009 at two sites off South Eleuthera to examine the survival and growth rates of grass sponge (Spongia tubulifera) and hardhead sponge (Spongia pertusa) cuttings. Complete skin regeneration occurred for both species by the second week following deployment. Following 43 months of growout, both grass and hardhead sponges showed significant positive growth, with cuttings of both species exhibiting faster growth trajectories at the more protected site (Site A) when compared with the site further from shore (Site B). The proportion of sponge cuttings lost during the course of the study was also considerably less for both species at Site A, as was the amount of required maintenance for the arrays. The initial deployment of larger sponge cuttings could help reduce the overall growout period, as would the selection of sites that offered more protection for growout. Based on these results, sponge aquaculture could prove to be a sustainable low-cost industry in The Bahamas; however, further research on site selection, regulations, and market acceptability remains to be done.