Predicting changes to seascapes under future climate, with the Coorong as a case study

The marine and estuarine ecosystems of South Australia are likely to alter significantly in response to a changing climate, but also in response to managerial decisions we make. The allocation of fishing effort is an example of one such decision. We summarise some projections on a state-wide basis for how different components of these ecosystems may be expected to change. We anticipate that tropical elements will expand in range but cold-temperate communities will contract or disappear from South Australia. As a specific example, we have modelled the ecosystem states of the Coorong and the Murray Mouth. We combined biological and physico-chemical components of an ecosystem into co-occurring units (termed ecosystem states) with well-defined thresholds between them. Predictions were then made using time series of inputs from modelled water flows and other predictors. Using this model, we will discuss the likely implication of a range of climate change and management scenarios, highlighting the potential impact on the commercial fishing opportunities. Specifically we will discuss the potential sensitivity of the fishery to climate changes versus various management options. Understanding these possible future changes should allow the industry to adapt before climate change reduces the sustainability of the industry.