Fish diversity in southern California using trawl data from the National Marine Fisheries Service

Data from 477 fishery independent trawls ranging from 55-1200 m in depth were collected June-November in 1977, 1989, 1992, 1995, and 1997-2002. Including all fish identified to the species level resulted in 189 fish species.

Using ArcGIS, 5 x 5 minute grids were created and mean diversity was calculated for each grid cell containing data. Gear included a nor'eastern trawl (127 mm stretched-mesh body; 89 mm stretched-mesh codend; and 32 mm stretched-mesh codend liner) with a rubber bobbin roller which was trawled for 15-30 minutes on the bottom. Zimmerman's (2003) analysis of benthic species biomass was used to cull out the trawls that did not fish the bottom.