Quantitative distribution of plant and animal communities of the phytobenthic zone in the Baltic Sea
ABSTRACT Contributions from the Askö laboratory ; 35 Pages: 80 p. : ill., graphs This paper quantitatively describes flora and fauna communities in the central and northern Baltic Sea, on vegetation covered substrate down to maximum 25 m depth, investigated by SCUBA-technique. In the Holmö area, on the sill between the Bothnian Bay and the Bothnian Sea, biomass was characterized by annual, mainly freshwater algae (e.g. Cladophora spp.) growing on the predominantly hard substrate of boulders, stones and pebbles. Muddy substrate, occurring in the shallow bays, had low biomass of freshwater phanerogams. The fauna biomass was dominated by freshwater molluscs (mainly Theodoxus fluviatilis L.) and the isopod Mesidothea entomon L.. Occasionally, Macoma balthica L. was abundant on sand and mud bottoms. Insect larvae were common but contributed little to total animal biomass.