Challenges for Diadromous Fishes in a Dynamic Global Environment

<em>Abstract</em>.-This paper presents a case study of a collaborative, watershed approach among hydroelectric utilities and natural resource agencies to restore diadromous fish stocks in the Santee River basin, a large Atlantic coast river. The basin once supported large populations of diadromous fish prior to the era of dam construction. A series of hydroelectric dams now block fish spawning migrations from the majority of the Santee River basin. Three of these hydroelectric projects are currently at various stages of the Federal Energy Regulatory Commission's relicensing process for non-federal hydroelectric dam projects. South Carolina Electric & Gas and Duke Energy Carolinas LLC, in concert with the U.S. Fish and Wildlife Service, the South Carolina Department of Natural Resources, and the North Carolina Wildlife Resources Commission, have developed the Santee River Basin Accord to address diadromous fish restoration in the basin. The Santee River Basin Accord utilizes a watershed approach to prioritize the Santee River basin's subbasins and determine the subbasin with the greatest potential for successful passage, spawning, and recruitment of diadromous fish. The process used water quality and quantity, spawning habitat, historic occurrence, quantity of riverine habitat, and the number of dams that fish must pass to access these habitats as the prioritization criteria. Based on these criteria, the Broad River subbasin was chosen as the priority subbasin. The Santee River Basin Accord will fund a 10-year restoration program for this subbasin that includes a hatchery-based restoration program, scientific studies, monitoring, and fish passage at dams that currently impeded spawning migrations. This watershed approach represents a collaborative and innovative method in the southeastern United States to manage and restore diadromous fish populations within a large river basin.