Savannah River Oxbow Fish

Savannah River Oxbow Study Update

by Jason Moak, Senior Research Manager

20150805 - Possum Eddy in Screven County (39)Phinizy Center researchers have completed their first round of fish community seasonal sampling in four oxbows along the Savannah River. In late July and early August, they collected a total of 1,044 individual fish representing 13 families, 19 genera, and 26 species.

In terms of numbers, bluegill were the dominant species captured, comprising 38% of the total number of fish captured. In terms of weight, longnose gar (57 kg) and gizzard shad (48 kg) made up the majority of the total of all fish captured (247 kg). A table listing all of the fish species captured in this sampling event is included below.

20150805 - Possum Eddy in Screven County (28)Phinizy Center sampled these fish communities using boat electrofishing and gill in collaboration with scientists from Georgia Southern University and Augusta University. The four oxbows sampled – Possum Eddy, Conyers, Miller, and Whirligig – each have an average depth of 5 feet or less and have surface areas of between 4 and 9 hectares. The lakes are located in Screven County on the Georgia DNR’s Tuckahoe Wildlife Management Area.

Oxbow lakes are remnant sections of river channels that have been cut off from the main river flow. Research on oxbows around the world has revealed their important role in supporting healthy rivers. In July 2015, Phinizy Center began a study examining the impact of various flows on the aquatic life in oxbow lakes found along the Savannah River downstream of Augusta. Our scientists are assessing the connectedness of many of the oxbows between Augusta and Savannah using high-accuracy GPS survey equipment. We are also monitoring surface and groundwater levels in four oxbows, two that are still connected to the river by surface water, and two that are disconnected. Additionally, Phinizy scientists are monitoring water quality and analyzing water samples for nutrient, algae, and zooplankton levels. This research is being funded by a grant from the South Carolina Water Resources Center at Clemson University.