Scientific support by the BONUS+ projects for the sustainability of the Baltic Sea Region: the case of the HELCOM Baltic Sea Action Plan.

The synthesis of the BONUS+ research is introduced. The HELCOM Baltic Sea Action Plan is examined as a case to illustrate the potentials and challenges in building the science-policy making interface on a macro regional level. The projects address environmental challenges in the Baltic Sea as defined by the Baltic Sea Action Plan, or consider the environmental governance and decision making within the Baltic Sea context in general.

Eutrophication, harmful algal blooms and species diversity in phytoplankton communities: examples from the Baltic Sea.

Understanding the mechanisms that govern biological diversity in various environments is one of the greatest challenges for the scientific community of today. Compared to terrestrial and benthic habitats, mechanisms regulating species diversity in planktonic ecosystems have been dealt with relatively little. This is mainly due to the scarcity of the experimental evidence from field studies where the multitude of spatiotemporal scales have been covered with sufficient resolution.

The history of cyanobacterial blooms in the Baltic Sea.

Long-term information on possible changes in cyanobacterial blooms in the Baltic Sea, formed mainly by Nodularia spumigena and Aphanizomenon sp., was sought in published records in historical (years 1887-1938) and modern (years 1974-1998) phytoplankton data sets. Old and new sampling methods and fixatives were tested to improve the comparison of data that had been collected and analyzed in different ways.

Growth, nitrogen fixation, and nodularin production by two baltic sea cyanobacteria.

In late summer, nitrogen-fixing cyanobacteria Nodularia spumigena and Aphanizomenon flos-aquae form blooms in the open Baltic Sea. N. spumigena has caused several animal poisonings, but Baltic A.

Occurrence of the hepatotoxic cyanobacterium Nodularia spumigena in the Baltic Sea and structure of the toxin.

Water blooms formed by potentially toxic species of cyanobacteria are a common phenomenon in the Baltic Sea in late summer. Twenty-five cyanobacterial bloom samples were collected from open and coastal waters of the Baltic Sea during 1985 to 1987, and their toxicity was determined by mouse bioassay. All of 5 bloom samples from the southern Baltic Sea, 6 of 6 from the open northern Baltic Sea (Gulf of Finland), and 7 of 14 Finnish coastal samples were found to contain hepatotoxic cyanobacteria.