Summer will bring on moderate amount of blue-green algae

In the most eutrophicated parts of Finland’s sea-areas, the Gulf of Finland and the Finnish Archipelago Sea, moderate to considerable amounts of blue-green algae blooms are to be expected this summer, estimate the Finnish Institute of Maritime Research and Finland’s Environmental Administration.
      The situation, however, is not forecast to reach the levels of the worst blue-green algae years of this decade.
      In the Bothnian Sea, the Bay of Bothnia, most parts of the northern Baltic Sea, and the easternmost areas of the Gulf of Finland the likelihood for the formation of surface floats of blue-green algae is small.
     
The peak of the flowering is likely to take place in late July, with the most blooms expected in the central and western parts of the Gulf of Finland, the southern Finnish Archipelago Sea, and the south-eastern and southern Baltic Sea.
      Should the early summer turn out to be calm and warm, the blooming may take place ahead of schedule in in mid-July.
      “The problem with the blue-green algae is that it prefers the same kind of weather as the holidaymakers”, says Juha-Markku Leppänen from the Finnish Institute of Maritime Research.
      “In the short term, it seems the blue-green algae situation might be slightly better than previously, but even if there was less blue-green algae, other algae types may still darken the water”, Leppänen points out.
      According to limnologist Seppo Knuuttila of Finland’s Environmental Administration, the conditions for the formation of toxic blue-green algae are not the best possible right now in the Gulf of Finland.
     
“Thanks to the ice-free winter the water masses have been mixed all the way down to the very bottom, and the oxygen situation in the whole sea area is therefore relatively good. A significant reason leading to the formation of blue-green algae is the internal burdening of the sea arising from phosphorus stored in the bottom layers being freed into the water under the conditions of lack of oxygen.”
      But even the internal burden is merely a result of the Baltic Sea’s external loading that has continued for a long time.
      The effluents from St. Petersburg still put significant strain on the Baltic Sea, as does for example the country of Poland.
      In Finland it is agriculture that is the single most important contributor to the sea’s eutrophication.
     
Helsingin Sanomat will follow the blue-green algae situation at Helsinki’s Munkkiniemi bathing beach throughout the summer.
      The beach will be photographed through the summer months and information will be gathered.
      Yesterday the beach was still clear of algae. On the beach there is also a blue-green algae detector, the readings of which will be updated on the www.luodedata.fi/hki Internet site three times a day.


Previously in HS International Edition:
  WWF: Climate change to increase amount of algae in Gulf of Finland (29.5.2008)
  Baltic Sea panel calls for tighter emission restrictions (19.5.2008)
  Baltic Sea needs urgent attention (14.4.2008)
  Warm August weather favours growth of algae both at sea and in lakes (9.8.2007)

Links:
  Cyanobacteria (Wikipedia)