Here in the Pacific Northwest, we hear a lot about threatened salmon populations. Depending on the perspective of the speaker, the blame is usually placed on any of a half-dozen external hazards including power-generating dams, over-fishing, and habitat destruction. Todd Sandell is looking at endangered salmon from the inside. He is studying the pathogen that causes bacterial kidney disease in Pacific salmon populations to find out how it affects populations, where it does the most damage, and what can be done to limit its impact.
Todd received the 2006-07 Flyfisher's Club of Oregon Graduate Fellowship for his many years of work in fish health. He has been combining the studies of salmon and immunology since 1998, when he first came to OSU for his master's degree. After completing that degree, he spent several years in the field, and then returned in 2005 to begin a Ph.D. in microbiology.
"People on my master's committee were somewhat amused to find out I was coming back to school when I swore I never would," he says. "What drew me back was the desire to teach at the college level. To me, the combination of research and teaching feels very constructive — something I can do to feed back into society."
Todd's research focuses on one of the most devastating pathogens of Pacific salmon, Renibacterium salmoninarum. He's studying the dynamics of infection in juvenile coho and Chinook salmon as they migrate from the Columbia River system into the near-shore environments of Oregon, Washington, and British Columbia. This research should lead to a better understanding of the influences of the pathogen on growth and survival of salmon and on interactions between hatchery and wild salmon stocks. Ultimately, it may help fisheries managers to curb bacterial kidney disease in hatchery salmon and limit transmission to wild salmon, aiding in the recovery of endangered Chinook and coho salmon stocks.
At age 37, Todd is older than most students in his program, and brings a richly varied work history to his post. His first job out of college was as a high school biology teacher. He then spent several years studying autoimmune diabetes, but left because he didn't like the climate in human medical research, which he found overly competitive and egoistic.
"I also made the decision based on the fact that humans are not in danger of going extinct any time soon, and a lot of other things are, including salmon. I've always thought fish were fascinating organisms, and I was happy to find a program where I could marry two of my biggest interests."
From his early enthusiasm for cellular immunology, Todd has been gradually drawn toward a broader focus on ecology and the enormous role of parasites and pathogens in ecosystems. The field of parasitology is changing to encompass the concept of disease ecology, including how environmental variables can impact the spread and severity of diseases.
"The most recent push in the field is looking at how climate change is likely to impact host-parasite relationships," he says. "That's really interesting stuff. I think I'd gotten to the point where I was spending a little too much time with the microscopes and pipettes, and it's been great for me to broaden my view."
In the first phase of his dissertation research, Todd established how many juvenile Chinook and coho salmon in near-shore Oregon and Washington ocean waters are infected with Renibacterium salmoninarum. With funding from the Flyfisher's Fellowship and a Mamie Markham Research Award, he has begun a second level of analysis to quantify how severe the infection is in each fish. This very specific information will help to explain the role the environment plays in patterns of infection.
Todd shares the goals of the Flyfisher's Club not only in his professional activities but also in his recreation. His advisors joke that when he's not in the lab or on a research cruise, he's probably thigh-deep in the nearest stream. "Flyfishing is very meditative," he says. "It's a nice way to get a deeper perspective on things."