Better aquafeed ingredients

 Microalgae as an aquafeed ingredient: In 2014, Kapuscinski and Sarker discovered a potential game changer that could help shift aquaculture from highly exploitative to more sustainable practices. Conventional aquafeeds use fishmeal and fish oil extracted from small ocean fish also called forage or bait fish; think anchovies. Aquafeeds, a 24 billion (USD) industry in 2014, use approximately 70% of the world supply of fish oil and fishmeal. The extracted commodities come from nearly a quarter of the world’s capture fisheries. This practice diverts healthy sources of protein and omega-3 fatty acids from the human food supply which further undermines food security in 36 countries. Not only does this reduce food for people globally but these capture practices are raising prices of fishmeal and fish oil for farmers in several sectors, and are threatening seabirds, tuna and other valuable large fish and mammals which feed on the same marine fish. The UN forecasts global supplies to run out by 2040 at the current rates of demand. The world needs affordable and truly sustainable substitutes for fish oil and fishmeal.

Motivated by this enormous challenge, we aim to produce a 100% fish-free diet using marine microalgae. We discovered that certain marine microalgae (Schizochytrium sp.) can replace the fish oil in aquafeeds for tilapia and shows promise for rainbow trout and salmon. Fish fed our Schizochytrium sp. diet show equal or better growth, food conversion ratios, and maintained good fatty acid content compared to fish fed a conventional diet (Sarker 2016) .We have also had success using microalgae “co-product” or useful biomass left over from nutraceutical production, as a protein replacement for tilapia. Initial results suggest that this protein rich biomass is effective enough to replace at least 33% of the fishmeal in commercial diets, and more with further ingredient processing. These results suggest our microalgae-feed formulas can improve the sustainability and help tilapia become a healthy global commodity.

Why Tilapia?

Tilapia are one of the most widely produced fish in the world, and increasingly, they are becoming less nutritious. Oily fish, most famously salmon, help provide people Omega-3 fatty acids, a key aspect in a well balanced healthy diet. However, terrestrial plant contributions and other animal by-products in their feed have lead to higher than normal levels of long chain-6 fatty acids; rather than the Omega-3’s most people eat fish to gain.

As a cultured species, tilapia are perfect. They are hardy, fast growing, and prolific. These fish can grow acceptably in sub-optimal living conditions and with poor feed content, but they thrive in good water quality conditions, when fed a highly nutritious diet.

Their widespread popularity as a food source, success as a culture species, and declining nutritional quality make them an ideal candidate. By providing a microalgae based diet we can improve the ratio of omega-3 to long chain-6 fatty acids, and reduce their overall environmental impact.