Simple “Solutions” for Aquaculture
At FENACAM 2023 in Natal, Brazil, Dr. Susan presented the "Simple ‘Solutions’ for Aquaculture" study.
Aquaculture is the fastest growing food production sector. To keep up with the growth, horizontal and vertical expansion with increased intensified farming has been employed. To be sustainable, aquaculture needs to have neutral or benign effects on the environment and economic feasibility. However, only 23-31% of total nitrogen and 10-13% phosphorus is retained as biomass by farmed organisms, while the rest is incorporated into the water column or sediment, and eventually discharged in the effluents toward the receiving ecosystems, causing diverse impacts. FCR or feed conversion rates is one of the strategic indicators on pond production. The smaller the FCR the more efficient the feed management. Since feed is 40-50% the cost of cultivation, a lower FCR is important. The ideal FCR for L. vannamei is 1.1-1.2. Higher FRC s are reflected in the higher amounts of organic matter, nitrogen, and phosphorous discharged in the effluents. Nutrification is the nutrient (N, P, C) enrichment of water column, mainly due to fertilization, mineralization of organic matter, resuspension of sediments, and excretion of organisms into the ponds. The greatest concern is the increasing production of nitrogenous metabolites especially ammonia, which is highly toxic to the animals.
Beneficial microbes have been shown to stimulate the animal’s immune system to improve disease resistance, and to outcompete pathogenic bacteria through exclusion. However, some beneficial microbes can consume organic waste and utilize ammonia, nitrite and phosphorus improving water conditions and reducing the need for water exchange. These waste digesting microbes consume the free organics converting them to bacterial biomass that is consumed by the animal improving the FCR. We have identified 5 strains of beneficial microbes that have been incorporated into our Waste and Sludge Reducer Product. We presented data to show that WSR works to improve aquaculture sustainability and we discussed the attributes of the microbes that make them an effective product.
