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.
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.