Measuring the contribution of ecological composition and functional services of ecosystems to the dynamics of KwaZulu-Natal coast fisheries

- We extend a bio-economic fishery model to establish an explicit link between ecosystems and economic behavior
- We demonstrate the dependence of this system on nutrient deposition and rainfall
- We estimate the impact of climate change in fish stocks and harvests

This study extended a bio-economic fishery model to establish an explicit link between coastal and estuarine ecosystems ecological composition (biodiversity) and functional (nutrient supply) attributes and the dynamics and productivity of KZN coastal fisheries. Results confirmed the importance and strong contribution of the tested ecological attributes. In-sample simulation indicates that current fishing efforts and harvest rates are sustainable, but are sensitive to changes in nutrient influx and rainfall. This confirms the need to modify conventional fisheries models to include environmental variables as additional predictors of fish stocks in addition to historical catch records and catch effort for management and control of fishing efforts and permits. This study provided confirmation of the strong linkage between nutrient levels and productivity of coastal fisheries thus enabling investigation of runoff and rainfall related climate change effects on the KZN fisheries.