CELS rising senior gains hands-on experience working with shellfish populations


Research fellow: Joe Barnes
Hometown: Suffield, CT
School: University of Rhode Island
Majors: Aquaculture and Fisheries Technology, Biology

Scientists know what happens with climate change — increased ocean temperatures, heavier rainfalls in shorter periods of time, higher emissions of greenhouse gases, and bigger loads of nutrients flushing into coastal waters.

The question remains, however, exactly what will be the cascading effects on marine life and ecosystems?

As a Summer Undergraduate Research Fellow (SURF) with Rhode Island NSF EPSCoR, Joseph Barnes, College of the Environment and Life Sciences (CELS), gets a firsthand look on the frontlines of investigation with the lab of Associate Professor Serena Moseman-Valtierra. At the same time, the rising senior gains the unique opportunity to help advance the body of science and bring greater understanding to the impact of these environmental changes on shellfish populations.

“Humans add a lot of nitrogen into the environment through waste management and fertilizer,” Barnes explains. “Oysters intercept the nitrogen and facilitate the process of denitrification, which converts it into a nonreactive gas. We’re looking at how different nitrogen loads and varying temperatures of water affect how efficiently oysters convert the nitrogen to a gas.”

Specifically, the project explores the impact on the eastern oyster, Crassostrea virginica, and blue mussel, Mytilus edulis, in regard to pathogen resistance, rates of nitrogen removal, and nitrous oxide production and/or consumption. Rhode Island has a vested interest in the eastern oyster with well established aquaculture and restoration efforts that continue to grow; the blue mussel enjoys an increasing commercial market within state waters.

If the oysters completely convert the nitrogen into a gas, says Barnes, the result is not harmful. However, he notes, increased amounts of nitrogen and higher water temperatures can interrupt the process and produce nitrous oxide, which is a greenhouse gas harmful to the environment.

For Barnes, the project allows him to work alongside Moseman-Valtierra and master’s student Ashley Hogan, and involves controlled lab experiments with contrasting  temperatures (18 and 24 degrees Celsius) and a gradient of nitrogen levels (20µM, 40µM, 70µM, 100µM), and testing rates of denitrification and nitrous oxide production of oysters maintained under these conditions. In the field, the researchers monitor two different points in Narragansett Bay, one coastal and another more inland, to gauge the the effects of water quality and tidal mixing on the health and function of oysters…[Read more]