By Jamie Sykes, Fisheries Biologist, U.S. Army Corps of Engineers Savannah District
April 13 marked the official start of the fish spawning season in the Savannah River Basin. That means Savannah District water managers started adjusting water management actions to accommodate optimal spawning conditions for fish in the reservoirs. The annual fish spawning management period typically lasts between four to six weeks.
Our objective is to maintain water levels with no more than a 6-inch drop in water level elevation to benefit fish that spawn in shallow water. This benefits many fish species, particularly the Largemouth bass, which is the most popular sportfish in the Savannah River lakes.
If the water should fall during this critical spawning period, fish will often abandon their nests, allowing nest predators to eat the eggs. A stable water level also creates flooded shoreline cover that provides juvenile fish protection for avoiding predators after they leave the nest.
This year there is an abundance of flooded cover at Hartwell and Thurmond reservoirs as a result of the vegetation that grew up on the shoreline during the extended drought period. With rising lake levels, this cover is now flooded and is providing conditions that usually result in high spawning success for our fisheries, such as Largemouth bass and Black crappie.
Managing the water during this critical period is the most significant thing that the Corps of Engineers can do to maintain sustainable fish populations for our current and future visitors. Our water managers do an excellent job of maintaining lake levels as stable as possible while continuing to meet the minimum water release requirements in the Savannah River.
While the objective of the spawning water level management is to provide optimal spawning conditions in the lakes, we must remain mindful that this is also a critical period for fish such as American shad and Striped bass that are spawning in the Savannah River below the dams. Just like managing other issues in the basin, managing lake and river fisheries is also a balancing act.