Increasingly ice-free winters and their effects on water quality in Sweden's largest lakes

Sammanfattning

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.

Nyckelord

climate; atmospheric deposition; ice; water chemistry; phytoplankton

Publicerad i

Hydrobiologia
2008, Volym: 599, nummer: 1, sidor: 111-118 Utgivare: Springer Verlag (Germany)

SLU författare

• Weyhenmeyer, Gesa

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

• Willén, Eva

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

Associerade SLU-program

Sjöar och vattendrag
Klimat


Globala målen

SDG6 Rent vatten och sanitet för alla


UKÄ forskningsämne

Fisk- och akvakulturforskning
Ekologi
Klimatforskning


Publikationens identifierare

DOI: https://doi.org/10.1007/s10750-007-9188-9

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/18606