Indicators for Climate Change Impacts - Lakes in cold ecoregions, Deep lakes
Water temperature effects on cold water fish
| Stressor type | Temperature |
|---|---|
| Responding parameter group | Biological parameters |
| Responding parameter | Water temperature effects on cold water fish |
Response description
Higher water temperatures (especially in the epilimnion) lead to the progressively reduction of thermal habitats for e.g. Salvelinus namaycush. As a result, cold water species will disappear from littoral areas in spring and summer. Furthermore, higher water temperatures will reduce reproduction success of cold water species and increase parasitic and predator pressure on the egg and young life stages.
Secondary effects
Warm water species might invade cold water region lakes with subsequently changes in food webs.
Specification of relevant ecosystem type
Relevant for all small lakes in cold ecoregions.
Relevant ecoregion(s) according to Illies
Borealic Uplands (20), Tundra (21), Fennoscandian Shield (22), Taiga (23)
Suggested indicator
Summer water temperature or air temperature
Justification of indicator
Water temperature is easy to measure, but even air temperature reflects warming up of mixed layer temperature, since increases in mean mixed layer temperatures correspond to 85% of increases in air temperatures.
Reference(s)
McDonald, M.E., A.E. Hershey & M.C. Miller (1996): Global warming impacts on lake trout in arctic lakes. Limnology and Oceanography 41(5): 1102-1108. Nyberg,P., E. Bergstrand, E. Degerman & O. Enderlein (2001): Recruitment of pelagic fish in an unstable climate: studies in Sweden´s four largest lakes. Ambio 30/8: 559-564.
