Finfish aquaculture often poses harm to the marine ecosystem through the associated output of nitrogen waste primarily in the form of ammonium (1 p.3). Managing this nitrogen output must therefore be an important consideration of aquaculture farmers and inform the way they set up and manage their farms. Growing kelp alongside finfish farms represents a potential solution to nitrogen pollution as well as providing other co-benefits and the Southern Ocean Carbon Company is participating in practical research through the Blue Economy Co-operative Research Council in part to realise this potential. The deployment of Macrocystis pyrifera (Giant Kelp) at sites adjacent to finfish aquaculture farms may provide a solution due to the nitrogen harvesting of giant kelp (1 p. 1). Modelling has shown that growing kelp next to farms can drastically improve the water quality of the system and provide economic co-benefits to practitioners (1, p.1).
Not only do these systems have the potential to benefit finfish aquaculture farms through improving water quality through processing their nitrogen waste, but in processing this waste there is an associated benefit of significantly improved seaweed growth as a result of the increased levels of nitrogen (Figure 2).
This suggests that close proximity to nitrogen sources is the ideal place to install giant kelp aquaculture in order to maximize production. This giant kelp biomass provides further value through a number of co-benefits. These include applications as a soil additive for terrestrial farming, as food, as an emerging alternative to conventional plastics, and also as a carbon sequestering agent to address climate change.