There are conservation challenges and concerns when it comes to aquaculture farming, and many environmentalists are worried about the ecological effects, especially of open cage fish farming systems, where pesticides, chemicals and nutrients can escape into the local environment, the possibility that disease can be spread between farmed and wild species and the overall lack of control over the growing environment. As a result, many producers are turning to recirculating aquaculture systems (RAS), these systems can be land-based with no need to be near the sea, river or lake and importantly provide a high level of biosecurity and environmental control, making it a safer and more sustainable means of supplying the growing global need for good quality seafood.

Waste produced by aquatic stock must be removed from the recirculating water in order to maintain health stock. This is typically achieved with a moving bed biofilm reactor (MBBR) which uses bacteria grown on the surface of media to remove the contaminants. Warden’s filter media allow for optimum biomass attachment, providing large protected surface area, creating a range of micro-environments conducive to the growth of different bacteria to ensure efficient removal of both BOD and ammonia.