Drinking water reservoirs confronted with global change

Faculty Seed Grant Projects

Managing human needs and ecosystem services in drinking water reservoirs confronted with global change

Investigators:

Dr. Cayelan Carey, Biological Sciences
Dr. John Little, Civil & Environmental Engineering
Dr. Madeline Schreiber, Geosciences
Dr. Quinn Thomas, Forest Resources & Environmental Conservation

Warmer summers are increasing thermal stratification in reservoirs, triggering greater hypolimnetic anoxia and sediment release of metals and nutrients limiting for phytoplankton. As a result, southestern U.S. reservoirs are experiencing both increased toxic cyanobacterial blooms and higher metal concentrations, threatening the long-term sustainability of water quality. Despite this challenge, reservoir models are unable to predict the effects of anoxia on metals and cyanotoxins over different time scales (minutes to decades) because there are few mechanistic datasets available to inform model calibration.
Our team will examine the effects of altered climate on nutrient cycling and food web dynamics of four drinking-water reservoirs that supply Roanoke. We will leverage our long-term partnership with the WVWA to experimentally manipulate anoxia with oxygenation systems to determine whole-ecosystem effects of increased metals, nutrients, and cyanotoxins. We will then use the field data to calibrate a model forced by regional climate scenarios to predict future water quality.

careylab — Members of the Carey Lab pose with a new weather station which was purchased using GCC Seed Grant funds. The station is now deployed at Falling Creek Reservoir.

Our project has three aims that capitalize on our interdisciplinary expertise:

examine minute-scale changes in the internal loading of metals in response to anoxia with new sensor technology
determine the trophic transfer of cyanotoxins from phytoplankton to fish in reservoir food webs
use the data from the first two aims to parameterize a reservoir water quality model to examine the effects of a suite of climate scenarios for years 2015-2100. Our research will revolutionize the understanding of how linked food webs and aquatic biogeochemical cycles respond at different time scales to global change.

This project leverages a strong, existing collaboration among five GCC faculty members with expertise in freshwater science, engineering, global change ecology, ecotoxicology, and biogeochemistry, and has a high likelihood of generating successful proposals and publications. With these data and models, we anticipate submitting multiple proposals for further funding, as this work is novel and relevant to drinking water, public health, and climate change science.