Aquaculture- the rearing and harvesting of animals and plants in all types of water environments has grown in the last few decades. This is due to multiple factors; the increase in human population and its demand of animal proteins, an international dietary move toward more lean proteins, and overfishing of wildlife for human consumption.
World per capita fish consumption increases at an average annual rate of 3.2%, double the world population growth of 1.6% annually.
Despite the rapid world growth, the primary consumers of fish and aquatic wildlife are those in developing countries, primarily tied to what is locally and seasonally available. This localism of fish consumption highlights the importance of keeping certain populations of aquaculture as healthy and productive as possible.
One way fisheries and aquaculture are maximizing their feed conversion ratio, and maintaining healthy populations is through the introduction of probiotics into fish feed.
The interest in using probiotics as an agricultural additive to support the beneficial bacteria in the guts of livestock has grown over the years. Probiotics is a way to raise healthy animals while reducing a reliance on antibiotics.
Using probiotics in aquaculture proves to be just as beneficial. However, their use is a bit more complicated. As aquatic creatures, the line between the microbiome inside the fish’s body and the microbiome of the underwater environment is very thin. The probiotics chosen must be willing to work with and support both of these microbiomes with equal effectiveness.
Studies show that the water a fish lives in is the primary source of that fish’s natural probiotics. The microorganisms cultivate in the environment and enter the host animal through feeding. By supporting the host and the host’s immune system with probiotic additives in the food, growers support the health of the environment’s microbiome.
A study out of Prince of Songkla University, Thailand found giving specific probiotics strains of bacteria (E. faecium) improved the intestinal ecology of Nile tilapia. These bacteria also grow best in the temperature best for the fish, the biggest challenge to microbial growth underwater.
Research suggests, like with their landlocked brethren, fish given probiotics grow better than those without probiotics, they digest nutrients better, and inhibit growth of bad bacteria better.
The biggest challenges facing probiotics application into aquaculture include poor bacterial stability in water during production and storage, too low bacterial concentrations, and incorrect application methods. As research continues and the demands of our growing world press on aquaculture new probiotics products may be the key to modern, sustainable aquaculture practices.