Sept. 21, 2016
Michael Wilkie has found that fish experience many unforeseen stressors in the natural world.
“Fish live in unpredictable environments,” says Wilkie, a Canadian Rivers Institute Associate and an associate professor of Biology at Laurier. “Sometimes they are affected by disease or parasites; at other times they are affected by physical changes in the water such as lack of oxygen or temperature changes. My research team looks at how different biological systems in a fish responds to these stressors.”
Wilkie and his team work to see how ammonia and oxygen deprivation alters brain function and metabolism in fish, as well as how fish gills are affected by exposure to toxins. Wilkie works with both ancient species of fish, such as sea lamprey, and modern fish such as goldfish and trout.
“Different fish species have different metabolisms and body structures depending on when they evolved from their ancient ancestors,” said Wilkie. “Their evolutionary history affects how they react to changes in conditions and chemicals found in our modern waterways.”
The lab also works to establish the toxicity of the pesticide, 3-trifluoromethyl-4- nitrophenol (TFM), which is used to control sea lamprey populations in the Great Lakes. Sea Lamprey are native to the Atlantic Ocean; however, they have colonized the Great Lakes as an invasive species. They prey upon Great Lakes fish such as trout and whitefish, often resulting in the death of thousands of host fish. The TFM pesticide is designed to specifically eliminate the lamprey and not other species of fish.
In practice, however, it has been found that TFM can adversely affect other types of fish at certain stages of their lifecycle and under certain water conditions. Wilkie’s research team is working to understand how TFM works to control lamprey populations in different water conditions, under different chemical compositions, as well as learning how fish process TFM through their bodies. This work will improve the control of lamprey in the Great Lakes.
“Some fish may thrive in environments characterized by unusual or extreme conditions; my lab aims to explore these extremes of fish health.”
Wilkie’s lab also works with fish other than lamprey. The lab recently received funding from the Natural Sciences and Engineering Research Council to study the neurophysiological basis of ammonia toxicity. Ammonia toxicity can occur in water environments where there is a large amount of dying organic matter, or in hatcheries where ammonia concentrations can get very high due to excretion by the fishes.
When a fish lives in an environment with a high concentration of ammonia, its brain can swell and the gills can be damaged, which harms the fish. However, specific fish species, such as the common goldfish, have evolved to withstand oxygen starvation, as well as tolerate environments with a high amount of ammonia. Goldfish are not negatively harmed by ammonia toxicity brain swelling – a poorly understood feature that Wilkie’s team is working to investigate.
“Some fish may thrive in environments characterized by unusual or extreme conditions. My lab aims to explore these extremes of fish health to understand why some fish thrive and others do not,” says Wilkie.
Wilkie’s approach to research involves training students in many hands-on techniques. Students that work in his lab perform tasks such as capturing fish in rivers for their studies using electrofishing and seine netting, and analyzing water samples.
“Giving students field experience though hands-on work in rivers and waterways allows them to really build their skills and appreciate the importance of our research questions,” says Wilkie. “Students thrive and find more meaning in their lab work when they can see their work applied to waterways and lakes across the Great Lakes.”
Wilkie’s lab has no shortage of challenges to address. As water temperatures increase in the Great Lakes, knowing more about how fish cope with stressors in their environment will become more and more essential for the health of our fish and the health of our waterways.
To learn more about Laurier’s water-based research activities, visit the Laurier Institute for Water Science.
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