The replacement of dietary marine fish oil with vegetable oils was examined in fingerling humpback grouper, Cromileptes altivelis, over the course of an 8-week growth trial. Five isolipidic (10%) and isoproteic (50%) fish meal-based practical diets were formulated to contain iso-ingredients but with different sources of lipids [crude palm oil (CPO), refined, bleached and deodorized, palm olein (RBDPO), soybean oil (SBO) or canola oil (CNO)], and their performance was compared with the control diet, which contained cod liver oil (CLO) as the added lipid source. The experimental diets were fed close to apparent satiation twice a day to triplicate groups of fish (10.6 ± 2.2 g). The grouper fingerlings were randomly distributed into groups of 12 fish in cylindrical cages (61 cm depth and 43 cm diameter) that were placed in a 150 tonne polyethylene seawater tank. There were no significant differences (P>0.05) in terms of growth, survival, feed conversion ratio, protein efficiency ratio, net protein utilization, hepatosomatic index and condition factor among fish fed the various dietary treatments. Similarly, the dietary lipid source did not significantly affect the whole body proximate composition of the fish. Muscle and liver fatty acid composition of fish was influenced by the experimental diets. Replacement of dietary CLO with CPO, RBDPO, SBO or CNO produced fish with lower n-3 highly unsaturated fatty acids and increased levels of 18:2n-6 in the muscle and liver. The n-3:n-6 fatty acid ratio in the muscle of fish fed the CLO-based diet was 3.0 compared with 0.5–0.8 in the muscle of fish fed the various vegetable oil-based diets. The present study demonstrated that various vegetable oils can be used in fish meal-based dietary formulations for humpback grouper without compromising growth or feed utilization efficiency.

Fish demand has been steadily increasing globally. Due to stabilization of harvest from capture fisheries the aquaculture has grown rapidly at the rate of 7.5 – 9.2 annually. Currently, the contribution of this sector to the global seafood supply has exceeded the landings from the sea. A review of fish production and consumption scenario was carried out in a systems approach that envisaged case-based reasoning for the synthesis of new knowledge. This enabled the identification of ways and means of applying modern technologies to the existing aquaculture production methods. How the aquaculture systems can be transformed by such interventions to further enhance its contribution to food security which is at the heart of all the Sustainable Development Goals has been elaborated. Technology access and adoption, workforce transformation, and adjusting to the global value chains are the issues that have to be addressed. In this context, research and development institutions can help by leveraging their resources and expertise in motivating a review of the existing policies and knowledge transfer to the farming communities to shape the development of aquaculture along the sustainability pathways.