The Columbia River is one of the most appreciated landmarks by Oregonians; we all love its recreational potential: gorgeous scenic hikes, windsurfing, and wine tasting, among many others. The Columbia River also provides critical habitat and passageway for many organisms, including federally endangered species such as Chinook salmon and steelhead trout, both emblematic species here in the Pacific Northwest.
A fact that might surprise you is that the headwaters of the Columbia River are located in Canada! Yes, our very own Columbia River starts its course in British Columbia and travels through Idaho, Montana, Washington, and Oregon on its way to the Pacific Ocean. The Columbia River is the second largest ‘big-river’ system in the United States with a watershed size of 660,480 Km2, and it is the West Coast River that brings the largest volume of water into the Pacific Ocean.
Since early 1900’s human activity has been a major driver of ecosystem change in the Columbia River, particularly the installation of dams for flow control and hydropower generation. Without the current dam system, the Portland Metro Area would experience massive flooding during heavy rain events and during the spring “freshet”, when mountain snow melts and the water level of the river rises.
However, the presence of dams in the Columbia River has lead to major changes in the riverine food web. Before the dams where installed the Columbia River was a fast-flow, high turbidity river where sunlight could not penetrate the water column due to the high sediment load in the water. The river ecosystem was driven by detritus (dead particular organic matter), which was the main energy source for the food web. With the installation of the dams, the Columbia River turned into a slow-flow, low turbidity river, where sunlight is able to penetrate into the water column, making the river a very friendly place for photosynthetic organisms, such as phytoplankton. We can say the Columbia River has turned from “brown” (high sediment, low light, high abundance of detritus) to “green” (low sediment, high light, high abundance of phytoplankton) as direct consequence of the installation of dams. I will discuss the implications of this switch for the Columbia River food web in another blog post.
The Lower Columbia River (the river stretch between the Bonneville Dam and the Pacific Ocean) is currently at risk from inputs of emerging contaminants, which have been documented in biota and in sediments. Emerging contaminants are “new” man-made chemicals. Only recently we have realized their conspicuous presence in water systems. Their effect on biological systems is not fully characterized (along with many other aspects of their fate in the water environment). Basically, we know they are going into the water but we don’t know much about what happens to them once in the water.
Some of such contaminants are 1) common pharmaceutical and care products (e.g. acetaminophen and DEET), 2) flame retardants (e.g. applied to furniture to decrease its flammability), and 3) plasticiers (e.g. Bisphenol A, the scary chemical present in some plastic bottles, which is considered an endocrine disruptor in vertebrates).
The study of emerging contaminants in the Columbia River, and any other freshwater system, is challenged by the detection limits of current analytical tools. Emerging contaminants are present in minute concentrations in the water (in the micro- to nanomolar range) and this poses a big analytical difficulty to researchers like me, with a limited budget for sample analysis. A wide spectrum chemical analysis costs around $800 per sample, a luxury that only some governmental agencies can afford. As part of my PhD project I will work on finding cheaper approaches to the analysis of some emerging contaminants that occur in the Columbia River. The success of my thesis basically depends on it!
This is all for now! I hope this introduction to the Columbia River system taught you a few new things about our beloved Columbia and gave you a new appreciation for how human activity has shaped, and is still shaping, the health and the basic functioning of this ecosystem.
Here is a list of upcoming blog topics around the Columbia River:
- From “Brown” to “Green”: changes in the Columbia River Food Web and Implications.
- Meet the microscopic inhabitants of the Columbia River
- The Columbia River will take the spotlight from 2014-2024, why then?
- The best part of my work: a day in the field!
- 12 hours of sampling in the Lower Columbia River and Estuary
- Career day at Sunset High School
- Emerging contaminants: sources, fate, and toxic effects in the Columbia River biota.