Spatial distribution of algae in <i>Ahnfeltia tobuchiensis </i>beds in Amursky Bay (Sea of Japan)
Horizontal and vertical distribution of algae in Ahnfeltia tobuchiensis beds was studied in the area of Mt. Stolovaya in Amursky Bay, Sea of Japan. Thirty-four species of macroalgae (2 species of Chlorophyta, 26 Rhodophyta, and 6 Ochrophyta) were found. Two unattached seaweed Ahnfeltia beds were located opposite Mt. Stolovaya and differed in area, macrophyte stock, number and biomass of attendant species, hydrochemical and light conditions. A monodominant community of Ahnfeltia tobuchiensis was formed in the southern bed, and a bidominant community of Ahnfeltia tobuchiensis + Ahnfeltiopsis flabelliformis occurred in the northern bed. The horizontal distribution of common species of macrophytes in the Ahnfeltia beds at Mt. Stolovaya is apparently conditioned by the amount of photosynthetic active radiation on the surface of the bed. Differences in tolerance of Ahnfeltia and attendant species to low light and light conditions across the bed define the vertical distribution of algae in the bed. Chondrus armatus and Ptilota filicina were chiefly common in the upper layer of the bed. A. tobuchiensis, A. flabelliformis, Chaetomorpha linum, and Coccotylus orientalis occurred across the thickness of the bed.