Effects of different management regimes on mangrove ecosystem services in Java, Indonesia

Background

Indonesia’s mangrove forests have decreased from 4.5 million hectares (ha) to under 3 million ha since the 1980s, largely due to the lack of monetary value attributed to mangrove ecosystem services, leading to conversion into aquaculture. Developing a valuation system for mangroves that includes both economically valuable products (i.e., timber, food) and ecosystem services allows decision makers to better assess the impacts of management decisions on the important ecosystem services and properties provided by mangroves.

Goals and Methods

This study aims to assess the impacts of different mangrove management regimes on mangrove ecosystem services in Java, Indonesia. The authors conducted a literature review and consulted with stakeholders to choose a set of mangrove ecosystem service indicators (i.e., food, raw materials, coastal protection, carbon storage and sequestration, water purification, nursery for fish and shrimp, nature-based recreation) and created a mangrove management regime typology for Java with five categories of land-use intensity (i.e., natural, low intensity use, high intensity use, converted for aquaculture, abandoned aquaculture). The authors compared each ecosystem service per management regime with a scoring system from -3 to +3, based on qualitative and quantitative ecosystem service information from the literature review, and then totaled the ecosystem service indicator scores for each management regime to compare between regimes.

Conclusions and Takeaways

Preserved, natural mangroves provide the most ecosystem services, except for shrimp and fish provision, and converting natural mangroves to aquaculture regimes could rapidly lower cumulative ecosystem service scores from +20 to -4. Rehabilitation of aquaculture by converting an aquaculture pond to a silvo-fishery or silviculture plantation regime could increase the score to +11 or +14, respectively, within ten years. This typology and scoring system allows for more equal comparisons between provisional, economically valuable ecosystem services and ecological, conservation-based ecosystem services of mangroves, providing a methodology that can help decision makers to more holistically assess the consequences of mangrove management decisions. The authors recommend pairing this methodology with a multi-criteria decision analysis that includes ecosystem services, health, safety, and employment to better inform and communicate mangrove management decisions.