Saline or brackish groundwater occurs in many parts of the world due to a variety of natural processes and quite often as a result of human activity. It is rarely viewed as an economic resource; quite frequently it poses the threat of contamination to valuable fresh groundwater supplies. As these freshwater resources come under increasing stress from population growth and agricultural and industrial development, some kind of intervention has to be considered by groundwater managers to avoid a deterioration in the quality of the groundwater they utilise. This intervention constitutes an overhead on the cost of supply.

This project, carried out by the Hydrogeology Group of the British Geological Survey (BGS) and the Aquatic Systems Group of the Institute of Aquaculture (IOA), investigated the possibility of using saline groundwater for aquaculture (the production of fish, shellfish, aquatic plants or algae). This could create a new economic resource and in particular, it could help defray the cost of protecting the fresh groundwater supplies.

The project was carried out in a series of linked phases, with appropriate contributions from the participating UK organisations and feedback from external (usually overseas) institutions.

The first phase of the project consisted of background reviews of the hydrogeology - particularly the hydrochemistry - of saline groundwater and existing, surface-water based, saline aquaculture systems.

This was followed by an assessment of the occurrence of groundwater salinity problems around the world and of local interest the proposed new technology. The assessment was based on a comprehensive questionnaire directed to appropriate research institutes.

Finally potential saline-groundwater aquaculture schemes at a number of promising locations were considered in detail and a methodology suggested for assessing other individual locations.

Aquaculture using saline surface water is undertaken in many locations around the world and as, in many instances, saline groundwater has a similar chemistry to estuarine waters it is concluded that groundwater systems could be equally successful. Indeed groundwater may have particular benefits such as freedom from pollution and parasites and warmer temperatures in winter that would promote fish growth.

However there are environmental implications and the additional cost of pumping the water from underground would probably prove prohibitive unless it was met elsewhere such as by a nationally-funded scheme to protect fresh groundwater resources. This limitation means that the potential development of saline-groundwater aquaculture will be restricted. The project was unable to identify any specific locations where the development of such schemes could be recommended.

Shearer¹, T R, Wagstaff¹,S J, Calow¹, R, Stewart², J A, Muir², J F, Haylor², G S, and Brooks², A C. 1997. The Potential for Aquaculture Using Saline Groundwater. BGS Technical Report WC/97/58.

(1 British Geological Survey, 2 Institute of Aquaculture.)

The project report was distributed to the institutes that contributed information to the project and other key organisations.