Aquaculture has been a method of food production for thousands of years, and is a viable method of supplementing wild caught fish in order to feed an ever-growing global population. Recently, studies have indicated that many fish stocks around the world will be extinct within the next fifty years if overfishing continues at its current level, increasing the focus on aquaculture. Traditional inshore aquaculture systems are associated with many negative environmental impacts including eutrophication, disease transmission, and habitat destruction. Advances in aquaculture pen technology, however, have allowed the movement of aquaculture operations into environments previously deemed unusable. The strong currents and wave action associated with the offshore environment actually reduce the overall environmental impact of aquaculture operations making them more sustainable by diluting and dissipating fish wastes.
Cobia (Rachycentron canadum) is an ideal candidate for offshore aquaculture. Its excellent growth rates and high food conversion ratio make it a commercially viable aquaculture species, and its firm white flesh and rich taste has made it a popular restaurant food with a competitive market price.
The objectives of the Cape Eleuthera Institute’s offshore aquaculture program is to produce marketable size cobia, from hatchlings to harvest, with a systematic approach to promote higher growth rates with a low food conversion rate, while mitigating environmental impacts. Starting in 2004 we have gone through two full scale grow-outs of cobia and this fall we plan to re-stock our offshore cage with up to 7,500 cobia. During previous grow-outs we had problems with shark predation which led to fish escapes. We are currently collaborating with two other corporations, DSM and Net-Systems Inc., to develop a shark resistant (ultra abrasion) netting.
Working in the Wege Center for Sustainable Fisheries wetlab, we have just completed our first trial of comparing different fish feed formulas on cobia that contain varying levels of wild caught fish protein. The goal is to provide nutritional food for cobia while reducing the dependence on wild fish protein. We are also developing a means of controlling parasites without the use of chemicals by raising cleaner fish, sharknose gobies (Gobiosoma evelynae), in our wetlab. These fish will be stocked larval rearing tanks in the wetlab and our offshore cage to help control parasite loads.
The offshore aquaculture project is proud to work in collaboration with the University of Miami Rosenstiel School of Marine and Atmospheric Science Aquaculture Program, the life material company, DSM, and the net manufacturing company, NET Systems, in the development of sustainable aquaculture. Click here for an update on University of Miami Experimental Hatchery's achievements.