A harmful algae bloom is currently occurring in parts of Västerhavet (Kattegatt and Skagerrak), according to the Swedish Meteorological and Hydrological Institute (SMHI). The bloom involves higher-than-normal concentrations of the phytoplankton species Pseudochattonella, which is not dangerous to humans or dogs but can cause fish mortality by damaging fish gills. No fish deaths in Swedish waters have been reported yet.
SMHI and the Information Center for Västerhavet are closely monitoring the situation. The algae bloom follows the spring bloom of diatoms and thrives particularly in spring when conditions are sunny with weak winds in the Kattegatt-Skagerrak area. During SMHI's latest environmental monitoring expedition with the research vessel Svea from March 12-14, the harmful algae were widespread along the stretch from Kullen in Skåne to Lysekil in Bohuslän.
Pseudochattonella has also been observed in samples taken along the Halland coast and in Bohuslän through regional environmental monitoring programs. A change in weather conditions could alter the bloom's development.