Data from five field surveys carried out along the shelf in the 20-250m depth range and historical data on artisanal fishery were analyzed. A positive linear relationship between the demersal fish biomass and the shelf area was pronounced for a certain (intermediate) stratum only: 50-100m. No statistical link was found for the strata above it (25-50m) and beneath it (100-150m and 150-250m). The pronounced one was associated with the low boundary of the oxygen minimum zone impinging on the shelf. Annual landings of demersal fishes in the region with the largest shelf area exceeded landings in the region with the smallest area by as much as 1.6 times. The ratio of small pelagic to demersal fish landings decreased as a factor of 10, from small to large shelf areas.