NERR - Research
Survey of Tidal Freshwater Faunal Communities
An electrofishing survey of fauna composition in South Edisto and Combahee rivers began in May 2001. The main objectives of this study are to determine relative abundance of fishes in the two rivers; compare the abundance and diversity of fishes between rivers; and determine the spatial and temporal distribution of fish species in the rivers. The riverbanks of the Combahee and S. Edisto rivers within the study area have been divided into 0.25 nautical mile segments. Each segment interval is considered a sampling site, and six sites are randomly chosen each month prior to a sampling period. Sampling is conducted monthly in conjunction with the Inshore Fisheries Section, and it occurs when the water is restricted to the river channel (mid-ebb through mid-flood tidal period).
Upper Combahee lies between the freshwater/saltwater dividing line (US Hwy 17) and the Cherokee Plantation (16 river miles upstream)
Lower Combahee lies between the freshwater/saltwater dividing line and the Chehaw Combahee Plantation (9 river miles downstream)
Upper Edisto lies between the freshwater/saltwater dividing line and US Highway 17
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A Smith-Root electrofishing boat is used to produce an electric field that flows between the conductive booms that are set forward of the bow and the aluminum hull of the boat. |
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Once shocked, finfish are removed from the electrical field using dip nets and placed into a live well holding tank in the boat until the site is completed. |
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The finfish are then removed from the holding tank, sorted by species, individually counted, measured and weighed. |