SHALLOW WATERS
On exposed coasts, the sea scours away sand and
other loose sediment. The bare rock provides a
hard surface for seaweeds which thrive in the
nutrient rich, sunlit waters.
Rocky areas also provide living space for many
animals which stick to rocks and wait for food
coming in with the waves and the attached life,
in turn, attract other creatures that feed on
them.
Living on the rocky shore is not easy. Although
there is plenty of food, waves and tides can cause
problems for the inhabitants. Waves batter the
shore – during storms a wave can hit the
shore with the force of a car going at 90 miles
an hour! Plants and animals have to bend with
the waves, hold on tight, lie flat or hide to
avoid being swept away.
As the tide falls, rocky shore inhabitants face
the problem of drying out – they have to
spend up to 6 hours out of water until the tide
returns. Many animals survive in rock pools, but
they must deal with changes in temperature and
salinity – on warm days the water evaporates
and raises salt concentrations; on rainy days
the pools may become diluted.
JELLYFISH ZONE There doesn't seem to be much to life as a jellyfish. We may think of them as alien-looking creatures, or as little more than quivering, stinging blobs washed up on the beach, but there is certainly more to jellyfish than first meets the eye!
Jellyfish are indeed very simple animals, made up of 95% water, with no bones, brain or heart, but they are found in all the world's oceans and have been successful for over 500 million years! Watch the moon jellyfish in the new Jellyfish Zone for a while and you will also see that, underwater, jellies are beautiful and graceful swimmers.
Moon
Jellyfish (Aurelia aurita)
Common in our waters, the gentle moon jellyfish has a fringe of short tentacles around the edge of the bell and ‘oral arms' in the centre. Its tentacles have a weak sting and the moon jelly also traps prey in mucus on the surface of the bell and then moves the prey to its mouth. Four purple rings can be seen through the transparent body – these are the reproductive organs, which are just below the stomach. There are simple sense organs around the edge of the bell for detecting light.
