Biology of Norwegian Lakes

Abstract

TBRAARUD, B. Föyn, and H. H. Gran, in a recent paper entitled Biologische Untersuchungen in einigen Seen des östlichen Norwegens August–September 1927” (Norske Videnskaps-Akademi i Oslo, I. Mathem. Naturvid. Kiasse 1928, No. 2), report on several lakes in the east of Norway with regard to the plankton and its environment. The work was carried on in a similar way, but for a longer period, in the Hurdals-See in 1926, and the results published in this same publication (1927). In the Hurdals-See the temperature, oxygen content, hydrogen ion concentration, and distribution of the plankton were investigated at different depths from May to October, the preserved plankton centrifuged and estimated quantitatively side by side with living net-plankton estimated qualitatively, the result showing that most of the species were in largest numbers in summer with a maximum in August-September. Only Dinobryon sertularia formed a maximum in June.