Bear with me because blogging is a new endeavor for me. My name is Emily Russ and I am about to enter my second year as a PhD student with the University of Maryland Center of Environmental Science where I study sediment dynamics in the Chesapeake Bay under the direction of Dr. Cindy Palinkas. Basically, this means that I get to play with mud, all the time! In more scientific terms, our lab group is interested in how fluvial sediment, or sediment that is eroded from a watershed, is transported to and/or deposited various places in the Chesapeake Bay.
Currently, our lab is involved with two research projects that were both motivated, at least partly, by the infilling of the Conowingo Dam, the last dam on the Susquehanna River before it enters into the Chesapeake Bay. Historically, the Conowingo Dam effectively captured more than two thirds of the sediments transported down the Susquehanna River before they reached the Chesapeake Bay. However, several recent studies revealed that the Conowingo Dam is approaching its sediment storage capacity, which means more sediment will pass over the Dam and into the Bay.
Why is this increase in sediment a problem? Sediment particles are not alone. They absorb and carry nutrients like nitrogen and phosphorus, which are just along for the ride. In other words, more sediment means more nutrients.
Although nutrients are beneficial for growing crops, excessive amounts of nutrients can be detrimental to waters like the Chesapeake Bay. When algae consume these excess nutrients, it can cause massive algal “blooms” on the water surface. The resulting algal mats cause two major issues:
- They prevent sunlight from penetrating through the water column and reaching seagrasses, which are essential for maintaining water quality, stabilizing the bottom, and providing habitats for various aquatic species.
- Eventually, the algae die and are subsequently decomposed by bacteria. However, in order to break down the algae, bacteria need to consume huge amounts of oxygen. When the bacteria deplete the oxygen in the water, other species such as fish, crabs, and oysters are unable to breathe in the water and die.
Reservoir captured sediment and nutrients, decreasing Bay inputs, improving water quality
Decreased reservoir capacity leads to increased sediment and nutrient input into Bay, impairing water quality
Therefore, it is of great interest to understand how an increase in sediment, as a result of the Conowingo Dam infilling, will impact Chesapeake Bay ecosystems. As I mentioned earlier, our lab is working on two major research projects related to the infilling of the Conowingo Dam:
- A Maryland Sea Grant funded study that investigates how Susquehanna Flats seagrasses, at the mouth of the Susquehanna River, influence sediment dynamics.
- A large, independent project that is funded by various sources, including Exelon Corporation and the Kerr Foundation, to examine how sediments and nutrients that pass over the Conowingo Dam will impact the Chesapeake Bay.
I am excited to be a part of these projects, and my dissertation research will involve integrating these studies to better understand sediment transport connectivity between the Conowingo Dam, Susquehanna Flats, and the upper Chesapeake Bay. I plan to chronicle my research progress through this blog, and use it as a platform to communicate my findings with you. I believe that this blog will be a learning journey for all involved, and I look forward to sharing more with you all in the future.