Did you know that brook trout are declining across Ontario in both numbers and habitat range?

This means that the brook trout species is in big trouble.

Local management agencies have recently acknowledged the decline in brook trout. They are starting to push for research to find solutions.

Karl Weise is a graduate student from Sault Ste. Marie in the Environmental and Life Sciences (ENLS) program at Trent University working towards a Masters of Science.

Karl’s research is investigating the role that stream rehabilitation, habitat fragmentation, and genetic testing have on the future of brook trout conservation in Ontario.


Focusing on stream populations, Karl’s research will address this issue and inform future management.

Using an Aquatic Ecosystem Classification (AEC) system, Karl is creating a local “indicator” of brook trout presence and seasonal habitat use in Haliburton County, Ontario.

Using this indicator, it can help us find our dwindling populations of brook trout and track their health and population dynamics.

During Karl’s field data collection he is employing techniques such as:

  • Environmental DNA (eDNA) sampling
  • Backpack electrofishing;
  • and physical stream characteristic quantification.

GIS mapping will enhance the applicability of this system and make it possible for other areas across Ontario to utilize the same methods.


Brook trout in Ontario have declined rapidly over the past two decades.

Karl has observed that many streams in Haliburton County that previously contained brook trout no longer do.

Furthermore, the streams that still do contain brook trout usually have them isolated to a few pockets within the watershed.


This research is critical.

Without it, we could see this beautiful species completely disappear from Ontario.

Losing the brook trout has many consequences, like:

  • Loss of ecosystem function and health;
  • Reduction in recreational fishing opportunities;
  • Elimination of tourism from many districts; and
  • Removal of economic boost that fishing anglers bring


We know that Karl’s research at Trent University can help conserve the brook trout in Ontario and keep fishermen and fisherwomen happy!!

His results will be useful in many ways and will help ensure this species survives.

Karl says,

“Trent University and my Supervisor, Dr. Tom Whillans, have provided me with an amazing opportunity to further my career and research goals. This hands on experience in Haliburton County is on the leading edge of research for the province and it wouldn’t be possible for me to get this anywhere else. The support and guidance, especially from Dr. Whillans, has been phenomenal and I couldn’t ask for better.”



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