Aquascope Facts
Cliff and rocky beach ecology

Eating above the surface

There are few animals that are able to eat when the cliffs are left drained at low tide because they will have to expose sensitive organs to the air and risk becaming dehydrated. To be able to search for food and be able to eat at low tide, animals like periwinkles need at least a moist surface under them. To accomplish this, they usually eat in moist micro-environments, for example at night, in fog or rain or when it is high tide. Mussels and barnacles on the other hand, have to be totally submerged because they catch their food directly out of the water.
   Algae do not need to eat, as they can produce their own food with the aid of photosynthesis. To photosynthesise, they need energy in the form of sunlight and certain bulding blocks such as carbon dioxide, water and soluble nutriants. Dehydration complicates photosynthesis as the needed building blocks are fetched out of the water.
Dried Enteromorpha 34 kB
Rockpools can be very advantageous for algae, for example Enteromorpha intestinalis. Sometimes, photosynthesis can be so intensive that oxygen bubbles occurr, but circumstances can change quickly. After a period of being left dry, the algae die and attain a white colour.

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Cliffs and rocks are fantastic!
Zoning and flecked occurrence
Animals that are attached
Modular construction
Variation and change
Variations in water level
Wave exposure
Both cliffs and rocks
Freshwater and saltwater
Geography, climate and history
Organisms life cycles
Organisms effect on each other
Energy and the flow of material

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