In the summer 1999 the alga Hydrodictyon reticulatum, called «water net» in English because of its netlike structure, was recorded from three localities in Oslo; the small lake Øtensjøannet and the ponds Kongsdammen and Hovindammen. The alga has been recorded from five localities in Norway. Hydrodictyon has a global, but scattered distribution. It was recorded as a newcomer after 1980 and is now the main nuisance alga in New Zealand. Increased occurrence has also been reported from England. The species' abundance at the Norwegian sites may be a result of low N/P ratios combined with periodically high water temperatures. Potential localities for nuisance growth of the alga include shallow ponds and small lakes in South Norway with high N/P ratios.
|Number of pages||6|
|Publication status||Published - 2001|