Fish Farming and Groundwater

Posted on 26 Jan 2018

The Council for Scientific and Industrial Research (CSIR), on behalf of the National Department of Environmental Affairs (DEA), is responsible for the Special Needs and Skills Development (SNSD) Programme which is aimed at providing Environmental Management Services, pro bono, to rural small-scale enterprises. The SNSD Programme offers assistance to entrepreneurs in the undertaking of a Basic Assessment Process for proposed developments that require Environmental Authorisation in terms of NEMA and the EIA Regulations, 2017.  One of these projects is the development of aquaculture farms.

Aquaculture is the farming of fish, crustaceans, molluscs, aquatic plants, algae, and other aquatic organisms. Growing public demand for a healthy tasty and affordable food is stimulating the industry. The decline in wild fish populations as a result of overharvesting and water pollution has promoted the culture of farm-fresh fish that are grown in contaminant-free waters in indoor tank systems.  At the moment aquaculture in South Africa is looking towards farming the Nile Tilapia fish species.

Nile Tilapia will be grown over 180 days per six months cycle. The fish will be stocked in the fish rearing tanks and then the fish waste (faeces and uneaten food) will flow into the settling tank. The process of biofiltration results in the conversion of toxic ammonia into plant friendly nitrates before the nitrate rich water is used to irrigate plants.

ENVASS has been a part of several of these unique projects and was recently tasked to complete hydrogeological studies relating to aquaculture farms which will feed into impact assessment reports as lawfully required.  The hydrogeological studies include a comprehensive hydrocensus of the immediate neighbours, sustainable yield assessments of the boreholes intended to be used to source water, as well as the associated water quality.