Towards marine ecosystem based management in South Florida: Investigating the connections among ecosystem pressures, states, and services in a complex coastal system.

Marine ecosystem based management plans are gaining popularity with natural resource managers, but examples of their successful implementation remain few. The complexity inherent in marine ecosystems presents a major obstacle to understanding how individual ecosystem pressures impact multiple ecosystem states that in turn impact the provisioning of ecosystem services. To create and implement successful ecosystem based management plans will require tools for understanding these processes. Over the past three years integrated conceptual ecosystem models of the coastal marine environment have been developed as part of the Marine and Estuarine Goal Setting for South Florida (MARES) project. Here we use these conceptual models in conjunction with a modified DPSIR model, expert opinion and matrix-based analyses to explore the direct and indirect relative impact of 12 ecosystem pressures on 11 ecosystem states and 11 ecosystem services identified through MARES. Within the South Florida coastal ecosystem the most pervasive pressures were freshwater delivery, temperature effects of climate change, and impacts of climate change on weather. For the study region the least pervasive pressures were recreational fishing, commercial fishing, and invasive species. The most at risk ecosystem states, as determined by cumulative impacts were fish and shellfish, protected species, and marine birds. By the same measure, the least at risk states were oyster reefs and inshore flats. The most at risk ecosystem services were existence of a natural system, pristine wilderness experience, and non-extractive recreation. The least impacted ecosystem services were commercial extraction, recreational fishing and climate stability. When the relative direct and indirect (i.e. including state to state interactions) impacts of ecosystem pressures were traced to individual ecosystem services, it was apparent that within the study domain a lack of freshwater delivery to coastal estuaries was the predominant pressure, and recreational fishing had the lowest relative impact on the provisioning of ecosystem services. Through this expert opinion analysis and exploration of the interaction strength among various ecosystem pressures, states, and ecosystem services, we can begin to understand the diverse manners in which ecosystem services are impacted by various pressures. In so doing we provide a tool for resource managers to understand the trade-offs among individual user groups and the possible impact on provisioning of ecosystem services that may occur when considering various management strategies. [ABSTRACT FROM AUTHOR]