coquina stone rockpool, green cladophora vegetation biodiversity, littoral zone underwater snorkel, oxygen rich

cladophora albida ulva rigida enteromorpha weed aquatic biological black sea bottom coast shallow bryopsis ceramium ecology environment flora shrimp landscape marine nature pattern rock salt ocean seascape seaweed submerged sunny travel odesa wildlife swim exploration space shell gravel torn muddy sand still mussel mollusc vegetation wave surface macrophyte algosociety photosynthesis oxygen synthesis selfpurification eutrophication