Dwellers of the Deep
What lake trout can teach us about climate change
Since the retreat of the glaciers 10,000 years ago, the top native predator in Adirondack waters has been lake trout (Salvelinus namaycush). The large, slow-growing fish inhabits the coldest, deepest lakes of the Adirondacks. Its species name, namaycush, is believed to be an Algonquin term for “dweller of the deep.”
As the longest-lived member of the salmon family, it’s not unusual for lake trout to live 20 years or longer.
Now they are helping us learn important lessons about climate change.
Why study lake trout?
- Lake trout require very cold (colder than 55°F), clean, high-oxygen water.
- They serve as a sentinel for change, bringing to light otherwise invisible changes in water quality.
- A decline can signal stress among lesser-known species such as Cisco and round whitefish.
How will climate change affect lake trout?
Mean annual air temperature in the eastern Adirondacks warmed by 2.1°F between 1976 and 2005, according to a 2010 report by the Adirondack and Vermont chapters of The Nature Conservancy. The range of anticipated additional warming in northern New York over this century is 6–11°F. Episodes of heavy rain have been more frequent in the past four decades than in the early 1900s.
Scientists expect these factors to eliminate a significant portion of Adirondack coldwater fish habitat over this century. Smaller lakes and those impaired by invasive species and fertilizers are most vulnerable. But a reduction in habitat does not necessarily mean regional extinction.
We can take steps now to identify best bets for long-term resilience—waters with ample cold water refuge in forested watersheds—and to monitor them and minimize other stresses.
What is The Nature Conservancy doing?
- Filling gaps in knowledge with a new report that updates the status of Adirondack lake trout and identifies emerging threats.
- Working with the New York State Department of Environmental Conservation and private fisheries managers to catalog all known lake trout habitats in the Adirondack Park.
- Identifying which Adirondack lake trout lakes are vulnerable and which show potential to serve as lifeboats in a warmer, stormier future.
- Assessing the size and health of the population of lake trout and cisco in Follensby Pond, a deep, oxygen-rich lake currently owned by the Conservancy, and using the information to craft a long-term management strategy for coldwater fish in similar lakes.
What You Can Do
The solutions we find in New York may help us address climate change in other places. Support The Nature Conservancy in the Adirondacks and help ensure our long-term success here and beyond.