Aquaculturally Derived Products as Fertilizers for High-value Organic Crop Production

The aquaculture industry in the Southeastern United States is valued at around $600 million at farm-gate. However, the industry suffers millions of dollars in lost revenues because of fish deaths and predation. Death of fish in ponds can be due to abiotic factors such as mechanical and electrical failures and to biotic factors such as disease. While over half of the live fish production in the region is catfish, the tilapia fish industry has shown consistent expansion. Tilapia is currently the second most important aquaculture species in the world and the third most important seafood commodity imported into the US after marine shrimp and Atlantic salmon. Since 1991, Tilapia production has increased at a rate of 20 percent per year. The problem of waste due to rapid reproduction and mechanical failure (aeration failures) necessitates the development of plans to deal with fish loss. If losses are high, the profitability of aquaculture enterprises is compromised and they will be unable to remain sustainable in the long term due to increased competition from Asia and South America. Generally, dead fish are of little or no value. However, if deceased fish are handled effectively, they can be converted into a potentially high-value organic fertilizer that has significant market value at the wholesale and retail level. Such fertilizers can eliminate the economic losses due to fish kill and overproduction. It is the purpose of this project to demonstrate that fish emulsions produced from tilapia co-cultivated with Spirulina algae, are effective organic fertilizers and will support the growth of various of high value plants. Dissemination of the results of this work will serve to stimulate the demand for fish emulsion and other by-products and simultaneously create an alternative market for products from the aquaculture industry. If the fish emulsion products can be certified as “organic”, then such certification will add a premium to the selling price and create increased demand for the product. There is significant potential to increase the economic sustainability of south east aquaculture enterprises by developing fish-based fertilizer. The producer intends to produce fish co-cultivated with algae to make 300 gallons of emulsion. He will characterize the product by submitting samples for laboratory analysis. And he will obtain preliminary estimates of the economic feasibility of production fish/algae emulsion fertilizer as an alternative product for aquaculture. In a series of experiments, he plans to test the fish emulsion fertilizer as a sole nutrient for support of growth of selected high value crops and compare yields with current state of the art production methods. He will set up demonstrations to show other producers how to cultivate and manage selected high value crops using the fish/algae emulsion fertilizer. He will also disseminate the results of experiments and demonstrations to others through field days, trade publications, professional meetings, and web pages.