Aquaculture Africa 2023

November 13 - 16, 2023

Lusaka, Zambia

KELP MARICULTURE’S POTENTIAL TO REDUCE NEGATIVE EFFECTS OF FINFISH AQUACULTURE ON WATER QUALITY

Adam Brancher*, Prue Brancher & Duncan Kreps

* Head, Blue Economy Solutions Southern Ocean Carbon Company-An ADEC Innovation 

Address: adam@southernoceancarbon.com

 



 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 Integrated multi-tropic aquaculture (IMTA)  represents a potential solution to nitrogen pollution as well asa variety of 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  . T he deployment of  Macrocystis pyrifera (GgG iant KkK elp) 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 such application of IMTA  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 theseIMTA 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 nitroge n (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 a n emerging alternative to  conventional plastics, and also as a carbon sequestering agent to address climate change.  Similar  co-location strategies may assist those looking to increase protein production in an environmentally sensitive manner.In this presentation, the Southern Ocean Carbon Company will show how it is tackling this problem in practical terms which will likely be of interest to a wide range of delegates

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