FISH 406: Parasite Ecology


Next offering: Autumn 2020

Parasites are ubiquitous: no ecosystem exists without them, and among all of Earth’s species, parasites outnumber non-parasites. But because they are usually small and hidden within their hosts, parasites can be easy to overlook. This course will introduce students to these rarely studied creatures, which span the entire tree of life, occupy all of Earth’s habitats, and influence many ecological processes.

Our material will survey all metazoan parasites, most protozoa, and some bacteria and viruses, addressing their distribution, ecology, and physiological effects on human and wildlife hosts. Because this is an ecology course, we will survey parasite diversity in light of evolutionary diversification. Phylogenetic relationships within and among groups will provide the framework for the course.

Within this phylogenetic framework, the bulk of our time will be spent exploring general disease ecology theory through relatable case studies of individual taxa. We will explore fundamental principles of parasite populations (e.g., SIR models, R0, frequency- and density-dependent transmission) and communities (e.g., co-infection dynamics, host heterogeneity). We will investigate the effects of parasites on host populations (e.g., host population regulation), communities (e.g., parasite-mediated competition), and ecosystems (e.g., nutrient availability). We will strive to put parasites into a food-web context, assessing the impacts of parasites on food webs (e.g., connectance, nestedness, energy flow, biomass, food chain length) and of food webs on parasites (e.g., dilution effect hypothesis, biodiversity-begets-biodiversity hypothesis). Finally, we will use our accumulated knowledge to make predictions for how disease transmission might respond to human impacts like biodiversity loss, climate change, and urbanization and will evaluate the interventions available for wildlife and human disease control (e.g., vaccination, culling, environmental modification, biological control).

Student feedback from official evaluations:

angel_with_ascaris“No one really talks about parasites in regular biology courses so everything was new and exciting.”

“I was so new to the world of parasites and the way Chelsea presented the information really made the concepts accessible and easy to learn.”

“Chelsea. She’s one of the most organized, well-thought out, clear speaking, receptive professors I’ve ever had. Her teaching style is very intentionally student success-focused, and it works very well. I came into this class thinking I’d be perpetually horrified and disgusted. I was, but in the best of ways. This was one of my favorite classes that I’ve taken at UW.”

“I can’t emphasize enough how much of an impact Chelsea’s teaching has on my experience with this class. I took this class on a whim to fill other needed credits, and I feel like I lucked out. Her engaged attitude and willingness to not only answer questions but find answers for those she couldn’t was amazing. The labs were awesome overall, it was such a unique experience to see the parasites in real life rather than in a textbook.”

“I love that this class is so interdisciplinary!”

“I learned so much in this class and absolutely loved it. Chelsea’s lectures are interactive and fun and packed full of great information. She asks questions of us and doesn’t just tell us the information, but encourages us to think critically and come up with solutions.”

“Dr. Wood is such a wonderful educator and this has been one of my favorite classes at SAFS! Her use of anecdotal stories to convey material was the most memorable aspect of this course. The content was utterly fascinating and her delivery made it truly enjoyable.”

“Getting down and dirty with all these parasites is the only way to go!”josie_with_schistocephalus

“This is by far one of the most intellectually stimulating classes I have ever taken. It wasn’t a challenge to do the extra assigned material because it was all so fascinating. I have recommended this class to everyone who asked.”

“The way that the term paper assignment is structured: turn in first draft, peer review, turn in second draft, prof review, turn in final graded draft, really helps with development of scientific writing skills.”

“Chelsea’s lectures are amazing. They are so engaging and inclusive of her students.”

“This class opened up an area of knowledge I have not even really considered, and it completely warped my view of how ecology works. I had always associated ecology with animals you can see, but parasites completely changed my view on how ecosystems function.”

“Chelsea’s enthusiasm and willingness to help when students were falling behind was very encouraging. I felt very supported.”

“I was always sad when the lectures ended. Chelsea is such a wonderful presenter and engages the class so well. I never felt like she uttered an unimportant word.”

“No suggestions- favorite class I have taken at UW.”


Exemplary term projects from Autumn 2018:

Jonathan Huie (undergrad), “Short- and long-term strategies for managing and mitigating the effects of Hematodinium on host species”

Emily Iversen (undergrad), “Recommendations on the control of Toxoplasma gondii infection in southern sea otters (Enhydra lutris nereis)”

Natalie Mastick (grad), “Controlling leptospirosis in California sea lions”

Kahana Pietsch (undergrad), “Report to the World Organization for Animal Health: Recommended measures to control Candidatus Xenohaliotis californiensis, the causative agent of abalone withering syndrome”


Exemplary term projects from Autumn 2017:

Ellie Davis (undergrad), “Control of Toxoplasma gondii in Enhydra lutris nereis, the southern sea otter”

Hiromi Katagiri (undergrad), “Augmentation of trematode parasite Euhaplorchis californiensis for conservation of coastal birds in California.”

Laura Spencer (grad), “Proposed measures to minimize the threat of Polydora spp. to Washington State shellfish aquaculture.”


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