Bottom Trawling and Dredging by Marine Ecoregion

Amount of fish and shellfish caught using bottom trawling and dredging (1955-2004), by marine ecoregion.

The map shows trawling and dredging fishing pressure by marine ecoregion between 1955 and 2004, using fish and shellfish catch data from the University of British Columbia (SAUP 2007). Our analysis of the catch data was limited to species caught by bottom trawl or dredge gear (Watson et al. 2006a). We calculated the annual total tonnage of catch for all species caught by these gears in each ecoregion. To account for recovery of benthic systems over time, we applied a decay factor of 2 percent for each year before 2004 to the total catch (implying a full recovery in fifty years). We then calculated the cumulative total catch for each ecoregion (including the decay function) across all years (1955–2004).

These data were derived by The Nature Conservancy, and were displayed in a map published in The Atlas of Global Conservation (Hoekstra et al., University of California Press, 2010). More information at http://nature.org/atlas.

Data derived from:
Sea Around Us Project (SAUP). 2007. Global fisheries database. Available at www.seaaroundus.org. Vancouver: Fisheries Center, University of British Columbia.

Watson, R., C. Revenga, and Y. Kura. 2006a. Fishing gear associated with global marine catches I: Database development. Fisheries Research 79: 97–102.