Linking human activity and ecosystem condition to inform marine ecosystem based management

There is growing consensus that integrated marine management is needed. However, implementation of ecosystem-based management (EBM) faces major operational challenges, including accurately delineating the links between ecosystem components and benefits to humans, and quantifying trade-offs associated with different management decisions. It is suggested using human activity level as an indicator of the benefit provided by marine ecosystems at a certain location in comparison with other locations and establishing links between human activity levels and ecological conditions. This approach allows for the determination of what ecological conditions may provide the greatest human benefits and thus may be targets for management action. This approach is used to investigate the link between scuba diving in the Monterey Bay area, California, USA, and different ecological characteristics of kelp forests. Diving intensity levels correlate with kelp persistence, suggesting that kelp persistence may be used as an indicator of benefits from diving and for evaluating the impact of potentially competing activities through their effects on kelp. Overall, an operational definition of marine ecosystem services is provided and it is suggested that this method could be extended to a suite of different activities and systems and thus may become useful in considering trade-offs among different activities that depend upon the same ecosystem.