Modifiers of impacts on marine ecosystems: Disturbance regimes, multiple stressors and receiving environments

Effective management and the maintenance of marine ecosystem services rely on a capacity to predict theecological consequences of environmental change and potential management interventions (Chapter 1). Making thesepredictions is difficult because anthropogenic stressors do not produce uniform or consistent impacts on biodiversity and ecosystem functioning. Rather, their effects can be modified by a variety of factors that cause them to vary among locations and different points in time. Thus, the effectiveness of actions taken to manage environmental problems is likely to vary in a similar way: interventions that are sufficient to mitigate a stressor's impacts in one situation might be inadequate or excessive in others. Both sound science and efficient management require us to recognise that spatial and temporal variability are inherent to natural systems, and that the ecosystem complexity places inherent limits on our ability to predict future ecological conditions. However, many ofthe causes of this variability have been identified. Careful consideration of these factors will enhance scientific understanding, improve ecological prediction and enhance our efforts to optimise marine policy and management by reducing the uncertainty associated with the effects of stressors.