Is the era of salmon farming in floating net cages coming to an end? More and more critics are calling for a shift of production to land-based facilities because of the numerous risks to which open systems in the sea are exposed: adverse weather conditions, toxic algal blooms, jellyfish plagues, diseases and parasites. Added to these hazards is the fact that floating farms have a strong impact on the marine environment. But would land-based farming really solve all the problems?

Well-being, growth and health of fishes depend to a large extent on whether particular physical and chemical parameters of their habitat correspond to the specific needs of their species. A large number of important measurements are taken during water analyses, but oxygen content, pH value and temperature are the most important factors. They must be constantly monitored in order to enable timely detection of any dangerous deviations.

Offshore fish farming has for some years now been considered a way to prevent some of the problems confronting coastal or inshore aquaculture. Offshore farming does have its own challenges, but these could perhaps be tackled using experience from the offshore oil and gas sector.

The sturgeon population is endangered in its existence worldwide. Numerous reasons have led to a dramatic decrease in population especially over the last two decades. Aquaculture can contribute to rebuilding wild sturgeon stocks and to meeting the demand for black caviar.

Although cobia (Rachycentron canadum) is still unknown to most consumers it is generally considered to be one of the most promising candidates for marine aquaculture. It is an excellent food fish. It grows extremely fast and is relatively robust. Its firm, white flesh has a nutty, buttery flavour and is rich in Omega 3 fatty acids. Everywhere, where cobia is already available on the market, demand is growing. Aquaculture production is rising.

Diseases are functional disruptions which can have adverse effects on the existence of all living organisms, including fish. In natural habitats such as rivers, lakes and seas, fish diseases often go unnoticed. In aquaculture systems, however, they are more easily recognized, particularly since high stock densities promote spreading of infection. Fighting these diseases is difficult because the necessary drugs are lacking or they are not authorized. This creates a state of emergency when therapy proves impossible.

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