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Climate changes affecting big river fish populations

June 20, 2019

Biology News Press releases Stories

No fish tale here — let our experts explain the mystery behind a rare, 100-year-old fish that was caught in Minnesota

Recently in Brainerd Lake … one lucky fisherman reeled in quite the catch. What looked like a giant goldfish was in fact a very old and very rare bigmouth buffalo fish.

The catch left a lot of people confused — what was it and how did it get there?

And that’s where our experts can wade in to help.

“We’re starting to study them more, and they’re living far longer than we ever thought possible,” explained Dr. Josh Lallaman, assistant professor of biology at Saint Mary’s University, and large river fish expert. “It shows the importance of not always focusing on popular species; there are other species out there that need to be researched.

“It’s often difficult for my students to understand that in fish identification color can be variable. Two individuals of the same species can look very different. That coloration (of the golden bigmouth buffalo) was pretty unique. It’s one of those situations similar to albinism. Every once in a while a rare set of genetic conditions makes species look very different from others. That’s what makes my job really interesting. There are these rare exceptions you don’t know are out there.”

Climate change is definitely putting more pressure on fish and wildlife populations. If their habitat changes, then their ability to survive in that habitat changes. It relates to this story in that if there are these unique or old lived species, then climate change is a threat to these unique individuals.

“In the end, we are decreasing species diversity within the populations. Climate change increases the temperature of the water, and it may not increase it more than a couple of degrees, but how quickly it changes has big impact on food availability. Fish are adapted to very specific seasonal changes.

Warmer water, even a couple of degrees, increases their metabolism so they’re hungrier and need more oxygen to survive but warmer water decreases the amount of oxygen in water. So it’s a double hit because they’re less active.

It’s synergistic. That stress, but also new and synthetic chemicals being introduced to in the water, as well as flooding and navigation — all of this combines together to harm fish populations a lot more than we realize,” he said.

  • Are you covering climate change and its impact on fish and other wildlife?
  • Do you need to know more about fish populations in rivers and lakes across America?
  • And what does the future look like for species and their ecosystems as the impacts of climate change starts to be seen and felt?

There are a lot of questions, and that’s where our experts can help.

Dr. Josh Lallaman is an assistant professor of biology at Saint Mary’s University, and large river fish expert. Josh is available to speak with media; simply click on his profile below to arrange an interview.

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Dr. Josh Lallaman, Ph.D.

Expertise: Big River Fish
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