Week 1: Jumping Right In!

In the last few decades, the Columbia River has seen a marked decrease in salmonoid populations. The cause of this decline is unknown, but the installation of hydroelectric dams in the Columbia River has changed the water clarity and sedimentation patterns, resulting in a greater contribution by pelagic phytoplankton to river primary production. This caused the food web to shift from being a macrodetritus-based food web to a phytoplankton-based food web. It is currently unknown how this shift affects Chironomids, a type of salmon prey, or the food web dynamics supporting the salmon population.

            During my time at OHSU, I will be studying the food web dynamics of the Columbia River, specifically examining the dependence of Chironomids on phytoplankton in this new phytoplankton-based food web.   A number of methods have been proposed for doing so including DNA sequence analysis of Chironomid gut samples and direct microscopic examination of their gut contents.

            I spent the first two days reviewing literature on Chironomids and their role in river systems. Because I did not know much about Chironomids prior to this project, reading other papers was very helpful for getting the necessary background information and context for the project. Additionally, the idea to study Chironomids at CMOP is relatively recent, so I am also searching for papers to give ideas for dissection protocols or taxonomic guides to both macroinvertebrates and phytoplankton.

            On Wednesday (June 11, 2014), Claudia and I went to take samples from the Camas site on the Columbia River. This was really exciting because it was my first chance to see the system I will be studying for the next 10 weeks. While there, we collected water for nutrient sampling and zooplankton samples. Though these collections will not figure prominently into my work, it was a fun outing, and it was great to see how the field research figures into the bench work.