Marine Mammal Ecology Lab


Holland's Blog

Holland Conwell, undergraduate student

1 September 2022

If all goes according to plan, I’ll be studying abroad in Greece by the time this blog post is up! It still sounds completely unreal as I’m writing this, but I’m so looking forward to becoming immersed in Athens and the surrounding area for the next two weeks. Since this is through the Honors College, I’ve of course had to tear through a huge stack of Homeric literature as a necessary prerequisite to my trip. This means I’ve had to really stretch myself these past few weeks when it comes to balancing readings, assignments, classes, the Summer Undergraduate Research Program, and full-time work on my projects. Needless to say, it’s been quite a busy month.

In the meantime, I’ve been hard at work on the first draft of my poster for the Summer Undergraduate Research Program. This has entailed a shift away from writing and a focus on conducting analyses, getting results, and figuring out how I wanted to communicate my findings on my poster. Aside from PERMANOVA and NMDS, I learned how to calculate Shannon indices in RStudio and display those results in bar graphs. Additionally, I ran a GLMM in hopes of finding what may be the most pronounced predictors of variations in Shannon Indices by site, with season alone as the result. I also found that Shannon diversity indices are pretty even across all sites except for Belle Chain and Fraser River. Both male and female harbor seals consume a greater diversity of prey in the late season at Belle Chain, while the opposite is true at Fraser River. On top of that, in September through December, males consume a more diverse array of prey at Belle Chain than females, while the Shannon index of males at Fraser River nears 0, which could reflect a male diet driven primarily by adult salmon at Fraser River. It’s certainly worth noting that Fraser River is composed of majority males (with a bias for salmon in the late season), making it a potential predation hot spot.

Fraser River especially stood out when I began to look specifically at diet proportions of Pacific salmon species, and it appears that male harbor seals at Fraser River eat more threatened Chinook salmon than females in the late season. In fact, visually depicting diet proportions of Pacific salmon species for my poster showed that more Pacific salmon appears to be consumed by males than females overall. While I’m only able to discuss a subsection of my results/figures on my poster, I’m still actively working on putting the bigger picture together. I’m excited to resume this work when I return!