They
are wonderful
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Some of those creatures that use tixotropi
when they dig, are worms,
gasteropods and mussels. They flush water onto the sand and make many
small penetrating movements whilst they push down into the sediment. In
this way, sediment resistance is decreased by 90%. When they anchor themselves,
the opposite phenomenon is used.
See what the
mussel does.
Sand beaches - organisms
Those organisms and creatures that are
most noticable when you visit the beach are those amongst the vegetation
in sand dunes, casual visitors (birds, mammals and insects) and organisms
that have been washed up and left stranded on the beach; (seaweed,
shellfish, mussels
and jellyfish).
Stranded organisms and organisms that the waves
have washed up, give us a splendid opportunity to observe and catch
many of the Marine organisms that are otherwise inaccessible to us because
of their depth or distance from the shoreline. Furthermore, the more permanent
inhabitants are affected by these casual visitors, in that they provide
a foof source, they themselves became a source of food and change the
physical environment.
Many of the permanent inhabitants are not noticed directly,
because they are either dug down into the sediment or are very small.
Take
a look at how it can vary in appearance both over and under the sediment
on a sand beach.
Plants
Amongst the sand dunes grow mostly lichens,
herbs and bushes. The sand is a very poor source of nourishment, but seaweed
and other organisms that are washed up onto the beach can supply a certain
amount of nourishment. Certain specie are totally dependent on this source,
and survive only on or close to these banks of washed up seaweed. This
source of nourishment is also utilized as a fertilizer in gardens and
fields, but it is necessary that the seaweed does not have contact with
the sea long enough so the rain has time to rinse out most of the salt.
Vegetation that grows amongst the dunes and these banks of seaweed must
tolerate high salt concentrations, most terrestial plants do not.
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