Inorganic chemical composition of sediment or rocks; Zoobenthos taxonomic abundance; Zoobenthos taxonomy-related wet weight biomass per unit area of the bed

A landscape map of the Gulf of Riga (scale 1: 200,000) is based on the materials of geological mapping (1984-1992) and the results of the investigations of zoobenthos and hydrochemical conditions ( temperature, salinity, content of oxygen ) in the near-bottom layer of water, that has been carried out at the Institute of Biology of the Latvian Academy of Sciences. The map shows the distribution of the landscapes, their genetic interrelation with bottom sediments. In addition, map shows the distribution of the pollution of the bottom sediments (scale 1:1,000,000) by six components: organic carbon, lead, copper, zinc, cadmium, mercury. The explanatory note includes the descriptions of the landscapes, the evaluation of the pollution of the bottom sediments and the estimate of prospects for the use of the basin in the national economy.