Forms of cultivation

Why aquaculture


Which specie

Problems associated with aquaculture

Cultivating molluscs

Cultivating blue mussels

Cultivation methods

Problems associated with mussel cultivation


Poisonous mussels?



Environmental questions associated with mussel cultivation

Mussel cultivation is based upon very little interference in the environment and is not plagued by the problems that are usually associated with intensive fish farming. Many feel that the mussel farms are ugly and a hinder for boat traffic.
    Blue mussels eat small particles that are suspended in the water, which results in the depletion of the amount of plant plankton that passes the mussel farm. Beneath the farm there is usually a concentration of organic and inorganic material, the result of the mussels digestive system that has been released as excrement. When bacteria under the farm break down this material, a great deal of oxygen is used and there is an obvious risk that the bottom below a farm becames oxygen deficient and result in the production of poisonous hydrogen sulphide. Oxygen deficient bottoms that produce hydrogen sulphide occur naturally in the sea.
    The cultivation of blue mussels appears to only effect the areas in direct proximity to the farms, but as the amount of waste increases, the environment and the specie composition changes under the farms. Animals that once lived on the bottom are replaced by small animals that live in the surface layers and are not effected by the deteriorating conditions further down in the sediment. It has been shown that such bottoms recover rapidly after a mussel farm has closed or been moved. The large fallout of material and dead or living mussels beneath the farm also has a positive effect as it attracts a great many crabs and fish, mainly different specie of flat fish. A mussel farm results in a large concentration of life within a relatively little volume of water.
    Studies have shown that blue mussels farms can have a positive effect on the Marine environment, mussels by eating plankton, bind many nutritive elements that are later harvested from the sea. This is of interest as large areas of our coastal waters are over fertilized. In this way, mussels can be used as part of a process for cleaning coastal waters.


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