Author |
Gunkel, G., Matta, E., Selge, F., Nogueira da Silva, G. M. & Sobral, M. |
Abstract |
Finfish aquaculture in net cages is widely used in Brazilian reservoirs, mainly for tilapia production. There is a large and increasing potential for production in the São Francisco River Basin, and particularly the Itaparica reservoir. Tilapia production amounts to 20,000 t y-1, with a licensed amount of 43,267 t y-1. This intensive fish production in net cages is responsible for a significant biological oxygen demand, and phosphorus and nitrogen load on the reservoir, which promotes eutrophication. Modelling of Ico-Mandantes bay has identified a reduced water exchange within the bay, with an accumulation of cage culture emissions in the water. The carrying capacity of the reservoir was determined using the P load model, with a critical P concentration based on the phosphorus use efficiency, and targets for more sustainable finfish aquaculture were established. |