Fish
Fish are a keystone species for the Kezar Lake fishing community, who have relied on abundant populations of cold water fish for their recreational enjoyment. These cold water fish species are extremely sensitive to changes in water temperature and chemistry. Cold water fish will seek cold, deep areas of lakes, ponds, and streams to avoid warm surface waters in late summer. This can be problematic in productive lakes that have depleted oxygen in bottom waters, leaving little habitat for these fish species to survive.
pH is particularly critical to fish species and other aquatic life as it affects their metabolic functioning and reproductive capacity. This is a concern for Kezar Lake and its ponds given the naturally-low buffering capacity of the soil and water in the watershed. Low-pH rain (5.0) temporarily decreases the pH of surface waters, placing significant stress on aquatic organisms residing in those waters.
If climate change enhances the frequency and duration of precipitation events, then sensitive fish populations may face high disturbance, low pH environments that may be fatal. Because of this, fish can be a good indicator of climate change and should be monitored.
As an invasive species in Maine, the northern pike is a voracious predator of other fish, frogs, crayfish, small animals, and birds. It was originally introduced into the Belgrade Lakes and resembles the native chain pickerel. There are no effective control mechanisms for this sport fish other than catch and kill. A compilation of invasive species of concern in Maine is provided in Appendix B of the 2018 CCO Annual report, which provides a description and image of these invaders and lists sources for more information on each species’ identification and mitigation.