Weyhenmeyer, Gesa
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
Research article2008Peer reviewed
Weyhenmeyer, Gesa A.; Westoeoe, Anna-Karin; Willen, Eva
Mean global air temperatures have steadily increased during recent decades, resulting in an earlier timing of lake ice breakup. In Sweden's largest lakes, Vanern and Vattern, the breakup of ice has occurred considerably earlier since 1979 and ice-free winters have become more frequent. Comparison between the years when the lakes were ice covered with those when they remained ice-free in terms of 37 lake variables revealed significant differences in water temperatures, sulphate concentrations and the biomass of diatoms in May after ice breakup (P < 0.01). In particular, the biomass of the genus Aulacoseira increased significantly, which may explain increasing complaints about algae that clog fishing-nets, filter-beds and micro-strainers in waterworks in Vanern and Vattern. We assume that Aulacoseira is mainly affected by changes in climate-driven water circulation patterns. In contrast, other observed water quality changes such as changes in sulphate concentration might rather be attributed to changes in atmospheric deposition. To explain water quality changes in Sweden's largest lakes it is important to consider changes in both climate and atmospheric deposition as well as catchment measures.
climate; atmospheric deposition; ice; water chemistry; phytoplankton
Hydrobiologia
2008, volume: 599, number: 1, pages: 111-118
Publisher: Springer Verlag (Germany)
Lakes and watercourses
Climate
SDG6 Clean water and sanitation
Fish and Aquacultural Science
Ecology
Climate Research
https://res.slu.se/id/publ/18606