Application of Acoustic Methods to Correlation of Fish Density Distribution and the Type of Sea Bottom

The application of acoustic methods for research on living marine .resourcesdistribution in relation-to environmental conditions has been developed at Sea Fisheries Institute at Gdynia for seve ral years.The paper presents parallel use of acoustic methods to evaluate the type of sea bottom and determination of horizontal distribution of cod, herring and sprat.The methods were applied together during two cruises of R.V. "Profesor Siedlecki" in» the area of the Polish fishery zone of Baltic.Geographical matrix of fish densities and bottom reflection properties was calculated and corresponding relationships were estimated.The correlation of distribution of fish densities and the type of bottom was found for cod, while for herring and'sprat it was not observed.