Projects

Mariculture

Aquaculture is rapidly expanding worldwide, and especially in Europe. Within the last decade the Norwegian Salmon production, for example, nearly tripled to 120.000 tons per annum. On the Scottish

Orkney and Shetland Islands production even increased fivefold.

Mariculture in offshore wind farms?

The offshore waters of the North Sea are less turbid and also cleaner than the coastal waters. Especially mussels and algae benefit from this condition. For this reason mussles and algae are particularly suited for farming in the German Bight as also the first research results of the Alfred-Wegener-Institute in Bremerhaven and the Terramare Research Centre in Wilhelmshaven show.

Another advantage: Installation effort for offshore aquaculture will be low - the wind farms provide most of the infrastructure needed. Longlines for mussel farming, for example, can be attached to the wind turbines. Wind farm operators will also profit from joint venture: When new wind farms are installed the area is closed for fishing. Aquaculture in wind farms could compensate for reduced fishing grounds.

Some hurdles still need to be cleared

Cultivating mussels in the open sea brings up new problems that must be faced:
» How will farming affect the ecosystem sea?
» Which practice is suitable for cultivation in the open sea?
» Of what quality will the mussels/ algae be?
» How can aquaculture farms be protected from harmful algal blooms?
» How can the risk of tanker accidents be minimized?
» How expansive is offshore aquaculture?

The problem with toxic algae

In summer 1988 a microscopic toxic algae, Chrysocromulina polylepis, killed about 900 tons of farmed fish. Four years later toxic algae and jellyfish killed several thousend tons of salmon from Norwegian and Scottish fish farmers. "Toxic algal blooms" are like a natural force.

Mussel farms are also affected by toxic blooms. As mussels feed on microscopic algae the mussels accumulate the biotoxins in their tissue. Humans consuming toxic shellfish will experience serious symptoms: nausea, incoordination, memory loss. Some marine biotoxins are even known to be lethal to humans. Therefore many states are currently designing early warning systems for toxic algal blooms. However, before being able to reliably predict harmful algal blooms many questions remain to be answered.

Documents

Mariculture Working Group - transcript of first meeting (German only)

Cooperation Partner

AWI - Alfred-Wegener-Institute, Bremerhaven (Bela Buck)
FTZ - Research- and Technology Centre West Coast (Uwe Walter)
Terramare Research Centre Wilhelmshaven (Uwe Walter)