coquina stone rockpool, green algae ulva vegetation thicket, rich biodiversity littoral zone underwater, oxygen rich low salinity

ulva rigida enteromorpha cladophora albida intestinalis aquatic biological black sea bottom coast shallow depth diving ecology environment flora grow 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