Development of decision support tools to assess the sustainability of coastal lakes

The sustainable management of the coastal lakes in NSW is under pressure from increasing urban development and tourism, intensification of agriculture, and the growing importance for the conservation of flora and fauna. An integrative approach is necessary to be able to manage for all these often conflicting interests. This paper presented a tool, called the CLAM (Coastal Lakes Assessment and Management) tool, which uses a Bayesian Decision Network to identify the likely impacts of management decision on social, economic and ecological variables within a catchment. Community consultation was an imperative component of the model development, and will also be pursued for model verification in the future. A CLAM tool for the Merimbula Lake was presented as a case study. The brief analysis of the model results given showed that active management of the Merimbula Lake catchment is likely to significantly improve the lake water quality. It also showed that urban development can proceed within the catchment without negatively impacting upon the lake water quality, if appropriate regulations are imposed and catchment management occurs. Various management options were shown to increase the local revenue, but not all of them did so while improving the lake's water quality. The CLAM tool is believed to be a useful tool and a dynamic approach, to assist catchment managers in making decisions. Ewing et al. (2000:456) comments that such tools are only to assist in decision making as they do "not substitute for the complex processes of judgement and the many political realities of planning". This is true, but at the same time tools such as CLAM, can show the impact of management decisions on social, economic and ecological values important to a community, and thus stand to highlight decisions made primarily for personal gain by those in charge, as has been the case in the past.