The beach is not the desert, however most of its inhabitants are minute forms - bacteriae, unicellular algae, microfungi,  nematodes and crustaceans. Number of annelids, shrimps and juvenile fish occur in shallow water at the beach

 Sandy beach of Polish coast is formed from quartz grains of some 0,3 mm diameter. As an effect of waves action the sea  water filtrates through the sand. This natural process retains number of suspensions, microorganisms and substances  present in sea water. One meter of wet sand at the coast filtrated from 10 to 1000 liters of sea water per day.