The main reason for the blooms is the increased nutrient load to the Baltic Sea. Last summer, the sunny weather served as an effective catalyst for starting the blooms. The occurence of blue-green algae is neither a new phenomenon nor is it anything unexpected. It represents, in fact, a conspicuous symptom of the poor state of our common sea.
BALTIC SEA PROPER
In Visby, the blooms were not as extensive this summer as they have been for the past ten years. However, one incident of cyanobacterial toxicosis affecting a dog was reported from the island of Gotland in July. The algae mats on the surface of the water did not reach the coasts of Visby and the Island of Gotland, remaining in the open sea. During earlier summers, the blooms had caused detriment to the island.
GULF OF FINLAND
In Helsinki, the blue-green algal blooms forced the city to close some of its beaches for most of the swimming season. During the summer several cases of cyanobacterial toxicosis were reported, both humans and animals being affected by the toxins in the water. The blooms aroused a lively political discussion in the city. In August the City Council called for a report on the situation and demanded that necessary steps be taken.
In the area of Kotka´s waterfront, the blooms were greater than ever from the middle of July onwards. Some of the blue-green algae reached the beaches of the town, but due to active citizen-directed information provision no cases of toxic reaction were reported. The Environmental Protection Office received many calls from concerned citizens during the blooming period.
GULF OF BOTHNIA
In Kemi, the blooms were more abundant than normally, but they did not cause any problems and were much smaller than, for example, in the Archipelago Sea. On the Swedish side, the blooms did not cause Sundsvall any problems either.
SOUTHERN BALTIC SEA
In the Bay of Gdansk the blooms were not a severe problem this summer, despite the fact that toxic species were found. In actual fact, the situation had been worse in previous summers. Outside of Kiel there was no appearance of blue-green algal blooms at all this summer.
As a result of eastern winds in the Bay of Koge, the worst blooming period lasted for two to three weeks in the middle of the summer. The city equipped its beaches with warning signs and there were also announcements in the local newspaper in order to warn the citizens. Even though toxic cyanophyte species were not found in the water, swimming was forbidden for some time. In Kristiansand, there was no occurence of algal blooms in the sea last summer, but the problem occured in some lakes.
According to the Sea Environmental Board in Riga, there were no blue-green algal blooms in the Gulf of Riga this summer, which contardicts the reports of the Finnish Institute for Marine Research. On the Lithuanian coast and the coasts of Klaipeda, high concentrations of blue-green algae were observed from the end of June to the end of August. Extremly high phytoplankton algae blooms were observed during the second part of July.
The Commission on Environment would like to thank the Finnish Institute for Marine Research for valuable information as well as the cities who participated in this inquiry. For more information on the blooms, please see the homepages of the Finnish Institute for Marine Research. There you will find the newsletter Alg@line with updated information in English, Estonian, Finnish and Swedish on the current situation.
