Reproduction of Resident Striped Bass in Santee-Cooper Reservoir, South Carolina

Abstract

An unprecedented sport fishery for striped bass, Roccus saxatilis (Walbaum), has developed in the Santee-Cooper Reservoir within the past 10 years. From a creel census from September 1, 1954, to August 31, 1955, the annual harvest was conservatively estimated to exceed 64,000 striped bass; this species accounted for 6.7 percent of the total harvest (by number) of all game fish caught. Exchanges between the reservoir population and those making seasonal runs in lower Cooper River is restricted to the navigation lock at Pinopolis Dam. Two methods were used during 1954 and 1955 to determine the extent of movement. Year-round fishing with a large trammel net indicated very limited use of the lock by striped bass. In 1954, a total of 606 striped bass were captured, tagged, and released in the Tailrace Canal below Pinopolis Dam. Out of 37 recaptures 33 were caught downstream, revealing a seasonal migratory trend, and only 4 had moved through the lock into the reservoir. To determine sexual maturity of striped bass in the reservoir, 165 male and 243 female fish were examined between February 16, and June 1, 1955. Most of the males were ride by the end of March. Changes in the ratio of gonad to body weight, were used to classify the stage of maturity of the females. A small percentage of the females were mature at 20 inches, total length. More than 88 percent of all females over 24 inches long had maturing, mature, or spent ovaries. The principal spawning grounds in the reservoir were located in 1954 by the collection of eggs in large plankton nets. In 1955 a more intensive study revealed that the spawning period started during the first week of April and reached a peak between April 21 and May 5. The minimum temperature for spawning was 58° F. Most of the striped bass in Santee-Cooper Reservoir are land-locked and apparently are able to complete a full life cycle in freshwater.