Application of Spirulina in aquaculture: a review on wastewater treatment and fish growth

There is an urgent need to find alternatives to fish meal and fish oil in compound feeds due to their rapidly rising prices and the demand for sustainable fisheries. Spirulina, a filamentous blue-green microalga, is an excellent source of plant protein and could replace expensive animal-derived proteins in fish feed. Studies have evaluated the use of spirulina as a fish meal for different fish species. This paper reviews research on the effects of spirulina on the growth performance of various fish species. It is apparent that spirulina can be a highly important component of the diet of fish; it has a number of benefits, such as promoting the growth of tilapia (Oreochromis niloticus) and carp (Labeo rohita), improving the reproductive performance of yellow tail cichlid (Pseudotropheus acei) and enhancing the immune response of rainbow trout (Oncorhynchus mykiss). Recent studies have shown that spirulina can be used for treating wastewater, including effluent from fish culture activities, as it can efficiently metabolize the nutrients and remove the heavy metals contained in aquaculture effluent. Fish aquaculture could apply an integrated strategy of simultaneously treating aquaculture effluent while producing spirulina biomass to supplement fish diets.