Other noticable changes during the year are the occurrences of different thread and leaf-like algae, how they succeed one another in shallow water and that large algae drop older and worn parts. It is during the spring one can see Chorda tomentosa. On the most wave exposed cliffs, the larger seaweeds are usually absent near the water surface and are replaced by short lived red algae such as Polysiphonia, brown algae like dead men´s ropes and blue mussels.    Not even where beaches are relatively protected are perennial algae found in shallow water in the Baltic. Here, the belts of fine threaded algae change during the seasons. The perennial bladder wrack in the Baltic is found first at a depth of about 1/2 m and deeper. Here, the deeper algal vegetation does not have the same variety as on the Swedish west coast. Below the alga zone in the Baltic, blue mussels almost totally dominate. Page 15 of 52
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