Mapping Ecosystem Service Flows in Cambodia's Great Lake Tonle Sap: Data and Knowledge Integration to Understand Fish Production and Biodiversity in Southeast Asia's Most Important Freshwater Ecosystem

Irit Altman
Research Scientist

Boston University

Friday, Apr. 3, 2015, 3:00pm
Chase 130

Marine and freshwater ecosystem-based management is an integrated approach that requires understanding how key spatial and temporal linkages support flows of ecosystem services (i.e., the benefits that human's derive from the natural world) across a relevant geography. While there currently exists much research on mapping single system features or processes in aquatic environments (e.g. bathymetry, sediments, biogenic habitat), identifying connections across data layers to explore the origins and flow of ecosystem services (e.g., maintenance of natural species' communities, delivery of economic opportunities, access to food and nutrition resources) is less often pursued due to challenges of uncertainty, multiple scales, and the need for cross-disciplinary thinking. At the same time, it is just this type of integrated thinking and analysis that is needed to support sustainable decision making in aquatic systems where the goal is to protect, maintain, and restore ecosystem integrity over the longterm.

In this talk, I present a conceptual and analytical approach for linking various types of spatial and temporal data within an ecosystem service modeling framework. The approach has been applied to marine and freshwater case studies in Belize, Massachusetts, and Cambodia and in each system our team has integrated across informational sources including remotely sensed imagery, seafloor mapping, regional- and local-scale monitoring data, and expert knowledge. I will focus most closely on the ongoing integrated modeling work for Cambodia's Great Lake Tonle Sap. Often called the, 'beating heart of Cambodia,' Lake Tonle Sap is fed by the seasonal monsoons of the Mekong Basin and exhibits an annual flood cycle that increases the inundated lake by six-fold (from 2,500-15,000 km2). This 'flood pulse' is a predictable feature of the ecosystem and contributes to high levels of biological productivity and diversity. Specifically, the Lake in the primary contributor to Cambodia's inland fish catch which has been estimated at 230-360 thousand tons in recent years. Furthermore, the lake and surrounding watershed are known to support diversity of fish (>400 species) and tetrapods, of which ~20% experience some level of threat. Our work is integrating a variety of data on this system including digital elevation maps, hydrological time series, remotely sensed landuse/landcover (LULC), and expert knowledge on suitable habitat for different species. Using rules about flooding and LULC, we predict the availability of important fish and tetrapod habitat under different management scenarios and explore changes in relative production of these groups. Changes in ecosystem services are considered in the context of the health and wellbeing of human populations that live on and around the Great Lake.


Irit Altman is a Research Scientist at Boston University with expertise in community ecology, ecological parasitology, ecosystem service modeling, and ecosystem-based management. She received her Ph.D. in 2010 from the University of New Hampshire where her research focused on understanding patterns of marine trematode parasite communities at multiple spatial scales. With an extensive background in marine field studies, Irit has been working most recently with a team of researchers to develop models of ecosystem service flows that support sustainable decision making. Ecosystem service models provide a platform for data integration, hypothesis development, decision support, and stakeholder engagement and can support adaptive management over the longterm.