North West Shelf Joint Environmental Management Study:InVitro Inputs - Primary production and nutrient cycling

Detailed models, embedded within the MECO circulation model, of the primary production and nutrient cycling on the NWS. And a detailed model of the NWS food-web was developed using the Ecopath-Ecosim-Ecospace models and software (Bulman et al 2006), Also an agent-based model of the food-web was developed for the NWS, but was found to be slow and inefficient at large space scales and to give very similar outputs to the faster model of Bulman et al.(2006). From examination of all these models it was found that there was very little interaction between the human uses examined by the MSE and primary productivity, nutrient cycling or the food-web. Instead the major affects of the human uses were through the more direct consequences of harvesting, habitat modification and water quality. With respect to fisheries this is consistent with the findings of Sainsbury (1988). So while these other factors were maintained in the MSE model, primary production, nutrient cycling and trophic interactions were not explicitly included. At higher exploitation rates and contamination levels, or a different set of human uses, than is currently envisaged on the NWS it is likely that the impacts on primary production, nutrient cycling and trophic interactions would become important.