Logo: SEA-U Marine Science Centre

Day 4

Raindrops keep falling on my head…

Another day of crappy weather. We had planned to finish the first part of the fieldwork in our mussel distribution project today. Unfortunately the wind and waves put a stop to those plans, but I can at least tell you about it.

Turning back  Photo: Michael Palmgren, Havsresan

SEA-U Marine Science Center (where I work) is today managing a mussel project together with the Region of Scania, the City of Malmö, and the municipality of Lomma. The project started off as a trial to reduce nutrients in Öresund. Common mussels eat microalgae, which as all plants utilize nitrogen and phosphorus in their growth process - by removing the mussels from the water you reduce the nutrient content in the ocean.

 Since the start, the project has had difficulties with the harsh weather conditions, which has shifted focus from nutrient reduction to developing a construction that can handle the ice, current, and wave situation in Scanias open waters (mussel farms are usually placed in sheltered areas such as archipelagos). At the moment the farms has been lowered three meters below the surface to cope with these strong forces.

Lowered mussel farm  Photo: Michael Palmgren, SEA-U Marine Science Centre

As a development of this  “farming” project SEA-U has started mapping the coast of Scania to find other suitable locations for growing mussels. The first step is to locate areas with high densities of mussels and larvae. This will be done by placing mussel collectors, which consists of a two-meter thick rope with a weight at on end and a buoy at the other, at a number of positions along the coast.

Drawing of a mussel collector  Image: Martin Karlsson, SEA-U Marine Science Centre

The common mussel starts its life as a larva before it settles down on a hard surface to transform into the shape we no as a mussel.  The limiting dispersal factor in the Sothern part of Sweden is usually the lack of hard surfaces, which is why hanging ropes in the water is a good method for studying the distribution of mussels.

The common mussel  Photo: Michael Palmgren, SEA-U Marine Science Centre

However this will not be done today…