Sand beach

They are wonderful


Algae can be found on submerged rocks as long as they are not chafed away or covered by sand. Where the sediment is protected enough from the waves, soft bottoms are seldom devoid of vegetation. There, they can attach themselves to the bottom without being washed away.
    More and more current and wave exposed areas, that were once devoid of vegetation, are now being covered by drifting thread-like green algae. A possible reason for this is the increasing discharge of nutritious effluent from urbanisation, agriculture, cellulose production and automoblie exhausts.

Gold brown patches of single-celled algae

Sand beach flora below the water line consists of a great many small single-celled alga. When waves wash up onto the beach and shift the sand, it is usually these organisms that survive. Sometimes they can be so many, that they appear as yellow-grey to dark brown patches on the sand. Many of these small organisms belong to the diatom group, which is also an important group amongst the plankton that floats about above the sand bottoms.
    Diatoms that creep about on and amongst the grains of sand - they are so small that several hundred can be placed on a single grain of sand. Their movements often follow variations in the light, creeping down amongst the grains during the night, and sitting on top of the sand during the day.

Other "plants”

Other groups that can be associated with the sand beach flora (certain groups can use sunlight to produce food) include flagellates, certain bacteria and fungi. It is very practical to divide organisms into plants and animals, but in reality, nature is much more complex.


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Waves, bottoms and construction

Sand movement and erosion

Sand bottoms as living environment

The art of digging

Sand beach organisms

Food web

Change and variation

Swedish beach life

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Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson