Author(s): Ivana Yuniarti
Email (s): s1779544@ed.ac.uk
Institution or organization of origin: The University of Edinburgh
Country: United Kingdom
Abstract:
Information on ecosystem services (ES) trade-offs is crucial in building knowledge-based decision making in the management of lakes. This research aims to provide such information by applying modelling tools to evaluate the trade-off between tilapia cage culture farm in Lake Maninjau, Indonesia, and production of Gobiopterus sp., which is a native fish species in the lake. The used tools are a Maximum entropy model and Bayesian Belief Networks. The results show that both models can assist the evaluation of the trade-offs. It was found that the fish cages offer a habitat to the wild fish but caused more frequent up-welling incidents which threatened both farmed and wild fish production. The trade-off is quantified in economic terms. The economic value of habitat provision reached more than one billion IDR (265 thousand USD) in 2018 and annual benefit forgone of Gobiopterus production due to up-welling approaches 0.5 billion IDR per year. The analysis can inform an assessment of efficiency of cage culture in the lake by comparing marginal costs and benefits of cage culture. By understanding the trade-off, decision-makers can perceive the impacts of cage fish production more objectively, and integrate the information in planning decisions on lake management. This can be facilitated through developing a user-friendly tool that illustrates the trade-offs and their economic impact.