ulva and cladophora green thicket on sandy bottom, littoral zone underwater snorkel, oxygen rich air bubble, low salinity

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