Predictability, Scale, and Biodiversity in Coastal and Estuarine Ecosystems: Implications for Management

This paper looks at coastal and estuarine ecosystems in terms of their unique biodiversity characteristics and the implications of these characteristics for management. With the exception of coral and other reef communities, coastal and estuarine systems are generally low in species diversity. But estuaries are typically dominated by strong aperiodic physical forces (e.g. salinity changes due to freshwater inflows, storm events) and under these conditions structure is more difficult to build and maintain. Estuaries are also characterized by a high degree of organism mobility. These characteristics point to a high degree of ecosystem resilience. The general hypothesis is that the biodiversity achievable in a system is a function of the predictability and scales of its physical environment. This hypothesis is consistent with the limited data on diversity in estuaries and other systems, and can be further tested in the future via comparative analysis. These ideas are elaborated and extrapolated to the task of managing complex and coupled ecological economic systems. Biological or species diversity is put in a systems context as a scale-dependent measure of an important system characteristic. In estuaries it is the diversity of ecological processes, and in particular certain keystone processes, that are more critical and that should be the focus of management efforts. Effective management is seen as the process of escaping from social traps that occur when local, individual incentives diverge from global, longterm goals.