Prawn larval density recorded from stepped oblique bottom to surface plankton tows in Albatross Bay, Gulf of Carpentaria. Nine cruises took place between 1975 and 1977 on chartered boats and the "Kalinda". Prawn larval biomass and densities were measured in several transects across the Gulf of Carpentaria, as well as total plankton biomass. These grids have been produced by CSIRO for the National Oceans Office, as part of an ongoing commitment to natural resource planning and management through the 'National Marine Bioregionalisation' project. The 'conversion factor' used to calculate the non commercial and commerical splits was derived from a spreadsheet containing Metapenaseus and Penaeus species. Commercial Metapenaeus spp. are M. endeavouri and M. ensis. The dataset was used to derive a commercial conversion factor. Thus the component of Metapenaeus spp. that are commercial; "Commercial Metapenaeus Prawn Larvae density" = 'conversion factor" x "total Metapeneaus prawn larval density" Conversion factor value 0.22. This was derived from all GOC data and checked for depths 5-20m, 20m, 30m, 30-40m, and 50-60m. It was found that the ratio of commercial Metapenaeus spp. to non-commercial Metapeneaus is constant with depth across the GOC.