Effect of substrates on periphyton production and their importance in aquaculture ponds - an overview

Aquaculture, especially commercial fish culture, is not always truly sustainable because of supply of external feeds, chemicals and energy inputs. The knowledge of feeding preferences by fish on naturally available food is scientifically inadequate and farmers always tend to use supplementary feed to increase income per unit area. Erection of natural substrates enhances the possibility of algal mat development in euphotic layer of the pond. These attached algal resources add new primary production and related benthic secondary production supporting new food web, part of which ends up in fish biomass. Such effort, in general, leads to detrimental effects on the aquatic environment. The positive effect of substrate based biofilm or periphyton on the overall pond ecology along with the higher production supports low input cost involved in periphyton based ponds, makes it a reliable production system. In particular, several studies have shown that the bacterial and microalgal biofilm growing on natural or artificial submerged substrates (periphyton) may be used successfully as the main or sole food source for several freshwater or brackish water fish species The applicability of this new technology needs to be reviewed, taking into consideration on the improved farming benefits involved. The current approach to enhance the natural food production in aquaculture pond is the application of substrate based periphyton production system in aquaculture industry.