S.C. Code Ann. § 50-5-20 – Jurisdiction of Department of Natural Resources

(A) The department has jurisdiction over all saltwater fish, fishing, fisheries, and marine resources within the salt waters of this State, including the territorial sea.
(B) The department is authorized to conduct research, surveys, and other investigations to manage fish and marine resources; to provide for protection of the salt waters and the marine habitat upon which these resources are dependent; and to provide for the development of saltwater fisheries and mariculture.
(C) Except as otherwise provided, the provisions of this chapter do not apply to fish or fishing in the freshwaters of this State.
(D) The provisions of this chapter apply to all impounded waters seaward of the freshwater/saltwater dividing line which are intermittently filled or drained by the action of the tide.
(E) Impoundments seaward of the freshwater/saltwater dividing line which are naturally occurring or are not influenced by the action of the tide are freshwaters for purposes of jurisdiction of this title.