In the autumn 2005 a vegetation survey assigned by the Government of Åland was conducted in shallow bays of the northern Åland. The main goal of this survey was to find possible stonewort-meadows and at the same time investigate the vegetation in previously poorly surveyed areas. The survey was conducted between July 5 and september 26, and the study area reached from northwest Geta to northern Saltvik including total of 28 bays. All together 88 survey transects were investigated, and from 218 squares the coverage of vegetation was estimated.
The methodology used in this survey, was adapted from the method used in “Rannikon vedenalaisen
kasvillisuusvyöhykkeen seurantaohjelma” by Finnish Environment Institute (SYKE). All the species encountered from transect, were noted as well as the maximum depth of the transect. Quality of the
bottom was also estimated.
The number of macrophyte species found in a bay varied from 2 to 15 species and the total amount of encountered species in this study was 40.
Of all surveyed bays nine had contiguous Chara-meadows, which covered a large area of the bottom.
In four of the bays (bay number 15, 16, 20 and 21) endangered species Chara connivens or Chara horrida
were found. All these bays are definitely worth of protection. Protecting the bays would mean prohibited dredging and limited boat traffic to preserve ecologically important stonewort-meadows.
Dredging is the most considerable threat to existence of contiguous Chara-meadows. Boat traffic and other human disturbance form considerable threats as well. Eutrofication affects mainly to stoneworts by increasing water turbidity and deteriorated light conditions
