Aquascope Facts
Cliff and rocky beach ecology
Operkulum Littorina saxatilis 6 kB
The rough periwinkle can close its shell apeture with a horny lid known as the operculum.

Many organisms that do not have a protective shell or case secrete a protective mucus.
It is relatively bad protection against dehydration, but is utilized by certian hydroids and anemones, for example the dahlia anemone. The mucus is not effective enough to enable the animal to survive the wind and sun on the bare cliffs.
    Different algae need to be positioned in such a way that they are able to collect sunlight, whilst many are lacking sufficient protection. In spite of the fact that they can lose much water, they have a remarkable ability of recovery. Bladder wrack for example can recover even after losing up to 70% of its water content.

Protection against heat and cold

Both the cold and the heat can injure or kill beach organisms, but it appears that most of the mechanisms that steer body temperature are geared to avoid high temperatures. This is accomplished in two ways:
(1) By reducing the flow of heat from the surroundings and
(2) by increasing the dissipation of heat from the body.
    One way of decreasing the absorption of heat from the surroundings is by having so little body area as possible. A spherical form has the smallest surface area in relationship to volume, the surface area in relation to volume also decreases with increased body size. Another factor is colour. White absorbs less heat compared to a dark surface. Therefore, large, round, white organisms absorb heat slowly. Because sun soaked cliffs and rocks can be very warm, it is important to have so little surface contact against them as posible.
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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