Dykare som simmar ovanför en musselodling
Foto: Tony Holm, Azote

 

Cultivating mussels for human consumption holds great potential for producing food from the sea, and possibly for producing sus- tainable feed for agri- and aquaculture. Currently, blue mussels are commercially farmed around the North Atlantic.

Recently, mussel farming has also been recommended as a cost effective measure to reduce eutrophication in coastal areas, including the Baltic Sea. The basic concept of mussel farming as a measure to counter eutrophication is that nutrients are taken up by the mussels and removed from the sea at harvest. However, blue mussels grow at a slower rate in the brackish Baltic Sea and have a lower meat and nitrogen content than mussels from areas with higher salinity. This means that cultivating blue mussels to take up nutrients from the sea has much less potential in the Baltic Sea than in other areas.

There are also still large gaps in knowledge about the environmental impacts of blue mussel farming in the Baltic Sea. The small-scale trial farms that currently exist in the sea have had little negative environmental effect, but at the same time, they have provided no major environmental benefits. The risk of negative effects grows if such farms are scaled up. For instance, we know that intensive mussel farming can lead to reduced oxygen levels in bottom waters and increased release of nutrients.

According to current knowledge, there is no scientific support that mussel farming is an efficient measure against the eutrophi- cation of the Baltic Sea.

Policy recommendations

  • Delay large investments in blue mussel farming as a measure against eutrophication in the Baltic Sea.
  • Account for the unique environmental conditions of the Baltic Sea.
  • Do not start any large mussel farms in the Baltic Sea until more is known about negative side effects.
     

KONTAKT

Linda Kumblad
Systemekolog, Östersjöcentrum
08 16 27 01, linda.kumblad@su.se

Sofia Wikström
Marinekolog, Östersjöcentrum
08 16 17 91, sofia.wikstrom@su.se

 

Read and download:

Policy Brief: Mussel farming in the Baltic Sea (520 Kb)

Report 2/2018 Mussel farming (1184 Kb)