Bladderwrack is one the few marine algae that can survive in the low salt content of the Baltic. It is counted as one of the ecologically most important species in the Baltic, where bladderwrack constitutes a major factor in the spawning, growth, and feeding of several commercially valuable fish species.

“If the bladderwrack disappears, there will be severe ecological and economic consequences for the region,” says Charlotta Nygård at the Department of Natural Sciences, Mid Sweden University. Charlotta Nygård will be submitting her doctoral dissertation in the subject of biology, and continues:

“It’s important for us to increase our understanding of the physiology and ecology of this key species before it’s too late. In the last few decades reports have been coming in that the bladderwrack has disappeared from different parts of the Baltic. Recently it was also reported that the cadmium content is increasing in the Baltic, which is something that the bladderwrack in the Gulf of Bothnia has proven to be very sensitive to.”

The dissertation reveals clear physiological differences between the bladderwrack in the Baltic and in the Atlantic. The environment of the Gulf of Bothnia is far from optimal for bladderwrack, which was shown when plants were moved to Atlantic waters and their photosynthesis increased markedly. On the other hand, bladderwrack moved from the Atlantic to the Baltic died within two months.

The bladderwrack in the Gulf of Bothnia lives in conditions that are just above the level of survival. Further losses in photosynthesis would mean no growth, and the alga would probably die in the near future. Environmental damage that results in reduced photosynthesis in bladderwrack can therefore have dire consequences for the survival of the species in the region, which in turn would negatively impact the whole ecosystem. As mentioned, one such threat would be an increase in the amount of heavy metals in the water.

The title of the dissertation is Ecophysiological responses of Baltic and Atlantic Fucus vesiculosus to environmental factors.

Questions can be directed to:
Charlotta Nygård, phone: +46 60-14 84 02; cell phone: +46 70-311 20 78; lotta.nygard@miun.se