Aquascope Facts
Cliff and rocky beach ecology Bacteria and fungi break down the more complex substances in the cell walls. It is something that protists and animals have difficulty in accomplishing. Protists search for food amongst the particles of detritus. They partly eat organic material that is already broken down, but they primarily eat those micro-organisms that speed up the breaking down process because the fungal and bacterial population is kept young and quick growing. Certain animals, for example certain shellfish and sea-urchins eat the detritus as it is, while suspension feeders catch some of the detritus particles that whirl up.
    Detritus material contains small amounts of protein. Alga remains are composed mainly of cell walls that mainly contain carbohydrates, e.g. celluose. There are several types of carbohydrates that cannot be broken down by many animals, this includes a majority of the detritus eaters. When algal detritus passes through the animals body only certain nutrients are taken up, the ones which the animal is capable of absorbing and from the micro-organisms that follow with the detritus. The remains that the animal leaves in its faeces are finely ground and thus enable the access of more bacteria and fungi to continue the breaking down process. Many of the micro-organisms have enzyms that can break up most carbohydrates that are found in detritus, futhermore, several of them can combine the seawater´s inorganic nitrogen compounds with broken down carbohydrates to build proteins. Detritus eating animals are dependant on these proteins because of their very one sided diet when they eat algal remains. Detritus material can pass through the animals digestive system several times before it totally broken down. Every time the waste products are colonized by new micro-organisms.

Exposed=export - protected=import

On the exposed rocky beach in our example, most of the larger algae´s production is exported as detritus. The majority of micro-algae´s production is eaten by shellfish in the same area. The large populations of suspension feeders are sustained by external production by the fact that they mainly eat plankton. Grazers, larger detritus eaters and suspension feeders are assailed by meat eaters. Some of these predators are in turn attacked by other meat eaters.
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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