AgBioResearch

Healthy fish are vital to Great Lakes restoration, and Michigan State University (MSU) AgBioResearch scientist Cheryl Murphy is on a quest to learn how fish are affected by stressors at both the individual and population levels.

While working on her master’s degree from the University of Alberta, Murphy began studying fish pheromones. In identifying these, she noticed that other, different chemicals could cause similar behavioral and physiological responses. If other kinds of chemicals could cause similar responses, Murphy wondered what type of havoc contaminants that mimic natural hormones could have on fish populations. So now she is working to identify sublethal effects of contaminants and stressors on fish populations.

“So often a lot of pollutants are regulated on the basis of how many organisms they will kill or how much human consumption can be allowed before it’s too harmful,” she said. “Long before a chemical or other type of stressor kills an organism – at very low levels – we get sublethal effects.”

Sublethal effects could be in the form of slow development or reduced ability to forage for food or avoid a predator. More severe responses could even limit an individual’s reproductive ability. Murphy’s current research focuses on how sublethal stressors affect the populations of perch and lake trout in the Great Lakes, and how those fish population effects could affect the larger fish community.

Her latest work on sea lamprey parasitism could have important implications for future research. In lake trout, the adaptations to the environment in fish being preyed upon by the lamprey had a significant effect on how the animal responded; fish from habitats deeper in the lake reacted differently than fish living closer to the surface.

“When we see a lamprey attack, we see sublethal responses– we see responses related to bioenergetics and responses related to endocrine disruption, and some of these responses are different between the two types of lake trout,” she said. “It’s kind of a cool story that has lots more to explore, but it’s the start of something really interesting.”

Results from her work will be applicable to the Great Lakes.

“It’s Great Lakes restoration, so anything that can quantify the effect of the stressor on these fish populations is relevant. If you can estimate the damage, then you can start a cost-benefit analysis. You have to estimate the damage that these stressors are having on the fish populations because then you can use the information to make decisions about how much of the stressor you’re willing to have.”

Question-and-answer Profile:

Q: What's your title?
A: Assistant professor in the Department of Fisheries and Wildlife and Lyman Briggs

Q: When did you join MSU?
A: January 2008

Q: What's your educational background?
A: Bachelor’s  degree from Dalhousie University, Nova Scotia; master’s degree from the University of Alberta in Edmonton; doctorate  from Louisiana State University; post-doctorate work at the University of Toronto.

Q: What's your hometown?
A: Edmonton, Alberta, Canada

Q: Who is your muse?
A: Jean Joss from MacQuarie University in Sydney, Australia. I worked with her for a couple months while I was in Australia. She built ponds to house  lungfish, which are a highly endangered species. The passion she had for these fish was just inspirational.

Q: What's your favorite food?
A: Pasta Primavera

Q: Best song or group?
A: "Boots or Hearts" by the Tragically Hip

Q: A book you recommend?
A: The Future Eaters: An Ecological History on the Australasian Lands and People" by Tim Flannery

Q: What's the coolest gadget?
A: The iPad.

Q: What's the best invention?
A: How do you narrow it down?

Q: What's the worst invention?
A: Email.

Q: What's one thing on your bucket list?
A: I'd like to go to Africa at some point. More specifically, the African Great Lakes. I’d also like to go scuba diving in the Maldives in the Indian Ocean.

Q: Who's someone you'd like to meet?
A: Rachel Carson

Q: What was your best vacation or favorite trip?
A: I took a seven-month trip through Australia, Thailand, Laos and New Zealand before I started my Ph.D. I volunteered in fish labs in exchange for room

Q: On a Saturday afternoon, where are you most likely to be found?
A: At some sort of music event. I actually have my own concert series, and traveling musicians come and play at my house. I have 10 concerts a year, and they’re just a lot of fun.

Q: What's a research break-through you'd like to see in the next decade?
A: What I’d like to see, in my field anyway, are models about the sublethal effects that are better predictors of population changes and help protect species.