The proposed project is suitable for a student who enjoys working in the field. As it involves boats and snorkelling, the student must be a confident swimmer (able to swim 200 m). Fieldwork would be conducted at the Askö Marine Laboratory outside Trosa, about 1 h south of Stockholm.

Bladderwrack (Fucus vesiculosus) is one of the most important species in the coastal areas of the Baltic Sea. Just like trees in a forest, they provide food and shelter for many small animals, fish and other algae at 0.5-5 metres depth. Since the mid-1900’s, large decline in bladderwrack belts have been observed throughout the Baltic Proper. The reasons for its decline have been attributed to eutrophication, chlorine effluents from pulp mills, and increased grazing pressure due to overfishing.

Within the national environmental monitoring of the vegetative bottoms are a time series reaching back to 1993 at 30 sites within the Askö area. At some of these, bladderwrack have declined over the years, but the reasons why have not yet been determined.

Proposed master project:

Check the abundance and composition of grazers at sites with stable bladderwrack belts and compare to those with declining and missing belts. Data will be collected in the field by the student. Some sites where bladderwrack has been present but declined/disappeared are documented by the national environmental monitoring, and this data will also be used in order to compare fauna species composition etc.


Ellen Schagerström

Susanne Qvarfordt