——Evaluating and Ranking the Vulnerability of Global Marine Ecosystems to Anthropogenic Threats
Human activities now affect nearly every marine ecosystem (e.g., Glover & Smith 2003; POC 2003). The number and variety of threats can be overwhelming to management and conservation efforts. Mapping where threats occur is important for management, but does not explicitly account for differences in the extent and nature of ecosystem responses to threats. For example, bottom-trawl fisheries have significantly more severe and long-lasting impacts on epibenthic communities living on hard versus soft substrates and even greater impact with increasing water depth because individual growth rates decrease and recovery times increase (Watling & Norse 1998; Thrush & Dayton 2002). Understanding these differences in ecosystem response is critical to knowing which threats have the biggest impact on different ecosystems and how to best address them at different scales. Quantifying these differences allows threats to be ranked based on the severity of their impact.