| | Accession Number | 5004024 |
| | Title | Effects of instream flow depletion on biological integrity of stream fish communities |
| | Project Description | In order to construct instream flow guidelines that will protect biotic integrity of streams, managers |
| | need to understand how biotic assemblages may change when flows are variously altered to |
| | meet human needs. This research will address this need by assessing fish assemblages in a |
| | sample of Georgia streams that are variously affected by water withdrawals or upstream |
| | impoundments. The project is a cooperative effort with the Georgia Wildlife Resources Division |
| | (WRD), and will provide specific data relating the integrity of native fish assemblages to degree of |
| | streamflow alteration. We will sample fish assemblages in approximately 40 stream segments in |
| | the Piedmont ecoregion of Georgia, including reference (least impaired) streams and segments |
| | that are variously affected by water withdrawals or diversions. We also will assess instream |
| | habitat conditions in each sampled segment. Fish assemblage data will be used to score sites |
| | according to an Index of Biotic Integrity (IBI) developed for Piedmont streams by GA WRD. Total |
| | IBI scores and individual metrics (e.g., species richness, relative abundances of sensitive or |
| | intolerant species) will be plotted against measures of hydrologic alteration for each stream |
| | segment. Degree of hydrologic alteration will be assessed from the magnitude of seasonal water |
| | withdrawals expressed as a proportion of average unimpaired flows. Regression and correlation |
| | analyses will be used to describe relations between fish assemblage characteristics and |
| | hydrologic alteration. We will use results to construct predictive models of fish assemblage |
| | response to streamflow depletion. We will use measures of instream habitat at low flows to infer |
| | potential habitat-related mechanisms linking flow depletion and fish assemblage changes. |
| | Keywords | biotic integrity, hydrologic alteration, instream flow, stream fishes, |
| | Principal | Mary C Freeman, USGS Patuxent Wildlife Research Center: mary_freeman@usgs.gov; |
| | Investigators |
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