Managing Fisheries in a Changing Environment
Some scientists use test tubes to conduct their experiments. Dr. Michael Rennie uses lakes.
As Canada Research Chair in Freshwater Ecology and Fisheries, Rennie is working with national and international partners to study the effects of pollution, climate change and invasive species on our freshwater ecosystems. By using a whole-ecosystem approach—and extensive long-term data sets from pristine lakes to help interpret their findings—Rennie and his collaborators can clearly show how lakes and the fish that live in them respond to environmental stresses.
In particular, Rennie’s research focuses on how fish species respond to stress, and how their responses can affect population dynamics and entire ecosystems.
Fish often move to other regions or are replaced by more tolerant species when climate change warms their lakes and rivers, or when they are affected by human activity. But fish may also respond to environmental change in more subtle behavioural ways—for example, spending more time searching for food, or delaying spawning. Even these subtle changes can have profound effects on their growth, reproduction and, ultimately, their population size. As their population size changes, so too will the ecosystem they occupy.
By better understanding how fish respond to environmental stress, Rennie hopes to contribute to the establishment of a whole-ecosystem approach to fisheries management that will support economically and ecologically sustainable fisheries in the future.