Fish migrating up the Santee River from the Atlantic Ocean face many obstacles as they return to spawn in freshwater areas in the heart of South Carolina. These diadromous fish – those that live part of life in fresh water and part in salt water – can hit a wall at Santee Cooper’s Wilson Dam, which they cannot pass. Others reach a bottleneck about 50 miles north of Charleston at the U.S. Army Corps of Engineers’ (USACE) Cooper River Rediversion Project. Fortunately, a fish lift allows them to continue their journey into Lakes Moultrie and Marion and beyond.
Another obstacle is the swarms of predatory birds, particularly White pelicans and cormorants, that follow the migration. Other birds of prey, like Bald eagles and osprey, are in the area year-round but have been joining in an all-you-can-eat buffet at the rediversion project. Scott Hyatt, USACE Operations Division manager for the Charleston District, says this activity is typical of recent years.
“We pass 500,000 or more American Shad and Blueback herring through the fish lift each season, despite the predation from birds and other fish,” said Hyatt. “Catfish and Striped bass also consume their share, but that is part of the purpose of passing these fish upstream,” he said. “Shad and herring serve as keystone species providing a major food source for both our freshwater and marine fisheries.”
An added complication this year is the severe drought impacting the region.
“The lack of rain so far this year in South Carolina is troubling,” said Hyatt. “That’s been limiting the amount of flow Santee Cooper can release to attract the fish. “Fortunately, we have a solid partnership with the South Carolina Department of Natural Resources and Santee Cooper, which helps us sustain this ecosystem and provides the best conditions to get fish past these blockages.”
The attraction flow of water is critical for fish migration. USACE coordinates with Santee Cooper to ensure there’s enough flow to entice the fish – particularly American Shad, Blueback herring and Striped bass – to trek upstream in the rediversion canal instead of up the Santee River to the Wilson Dam. While fish cannot currently pass the dam, Santee Cooper has been testing methods for fish passage and may install a permanent structure in the future.
USACE proposed the Cooper River Rediversion Project in the early 1970s to reduce sedimentation and dredging costs in Charleston Harbor. Army engineers began construction in 1978 to redivert water flow from Lake Moultrie back to the Santee River and completed the project in March 1985. The project saves taxpayers $36 million per year in dredging costs while benefitting shipping, industrial development, hydropower, and fish and wildlife.
USACE designed the St. Stephen fish lock specifically for American shad and Blueback herring, but Striped bass, catfish, and other species also pass through it.
The fish lift is open for tours by appointment only. The South Carolina Department of Natural Resources (SCDNR) offers tours of the St. Stephen fish lock and the Bayless Hatchery. Contact the SCDNR Dennis Wildlife Center in Bonneau, S.C. at 843-825-3387 for more information. In addition to seeing fish passing by the viewing room windows, visitors can observe numerous bird species and gain a deeper understanding of how the project sustains the local ecosystem.
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