Mapping the Cumulative Impact of Human Activities on Marine Ecosystems

Mapping the Cumulative Impact of Human Activities on Marine Ecosystems by Ben Halpern of the National Center for Ecological Analysis and Synthesis (NCEAS) (July 8, 2009).  Despite technological advances that now allow people to access, exploit or affect nearly all parts of the ocean, we still understand very little of the ocean's biodiversity and how it is changing under our influence. This presentation demonstrated methods for mapping the impact of human activities on marine ecosystems. Steps in the mapping process include gathering or creating maps of individual human activities that impact marine ecosystems, estimating the ecological consequences of these activities by quantifying the vulnerability of different ecosystems to these activities, creating a cumulative impact map by overlaying individual threat maps and using vulnerability scores to estimate ecological impact, and, finally, ground-truthing impact scores.  The resulting cumulative impact map provides critical information for evaluating where certain activities can continue with little effect on the oceans, where other activities might need to be stopped or moved to less sensitive areas, and where to focus efforts on protecting remaining pristine areas.  Learn more about this work at

Download the recording of the presentation [Windows Media .wmv format].  If you have problems downloading the file from this site, please try this alternate link.   If you are unable to download the recording, please .