Freshwater Integrated Multi-Trophic Aquaculture (FIMTA): Applying criteria for plant selection and the effect of plant species on the bioremediation of aquaculture effluent
University of New Brunswick
The environmental impacts of nutrient loading from freshwater Atlantic salmon aquaculture could be reduced by implementing freshwater integrated multi-trophic aquaculture (FIMTA) systems. Decoupled aquaponics diverts effluent from freshwater finfish aquaculture, containing essential plant nutrients, to a separate component for use in horticulture with hydroponic growing techniques. An experimental deep water culture system using effluent from a commercial salmon hatchery as nutrient solution tested 15 plant species over three 6-week nutrient removal trials. Parameters assessed were the nutrient content (nitrogen and phosphorus) of the effluent, water chemistry changes with plant treatments, yield, and nutrient contents of plant tissues. The experimental system supported the growth of 12 of the 15 species. The microbial safety, metals, and contaminant contents of system-grown lettuce were assessed. Large outputs of waste from Atlantic salmon hatcheries should be seen as a co-product and opportunity for local and diverse vegetable production, while strategic species selection influences effluent remediation.