Food and Feeding of Young Striped Bass in the Lower Roanoke River and Western Albemarle Sound, North Carolina, 1990-1991
Rulifson, Roger; Stanley, D.W.; Cooper, John E.
This study was conducted during the springs of 1990 and 1991 to provide information on possible causes of the decline in the Roanoke/Albemarle striped bass stock. Striped bass in this system migrate approximately 130 miles upstream in the spring (April through June) to spawn in the main channel of the Roanoke River. This location is the primary and only documented spawning ground for this stock. Spawning activity, and subsequent passage of developing eggs and larvae downstream, is directly influenced by water releases from Roanoke Rapids Reservoir at River Mile 137, which controls 87% of the lower River instream flow. A number of environmental factors have been suggested as potential contributors to stock decline: channelization, dredge and fill projects, dams and impoundments, industrial water intakes and discharges, chemical pollution, turbidity, low oxygen levels, sewage outfalls, poor timing of water release from reservoirs upstream, reduced spawning habitat, reduced nursery habitat, poor food availability, generally poor water quality, and spawning grounds too accessible to fishermen. All these factors in combination may cause a number of biological problems for striped bass such as reduced egg viability, poor survival of larvae during downstream drift from spawning grounds to nursery areas, and poor survival of juveniles on the nursery grounds. The objective of the study was to collect information about the food chain in the lower River, Delta and western Albemarle Sound during April through June and how it changes under prevailing environmental conditions, especially river flow. Data sets on water quality, larvae, and zooplankton generated by this study will be used by the U.S. Geological Survey to assist in calibrating the hydrological models being developed for the lower River and Albemarle Sound (i.e., providing concurrent biological data with their hydrographic modeling efforts). An understanding of the transit times and resultant distributions of zooplankton and larvae within the watershed under different flow regimes could assist resource managers in controlling river flows in the spring to increase chances of successful striped bass recruitment.
Completion Report for Projects 90-2 and 91-2 to: North Carolina Striped Bass Study Management Board, and North Carolina Wildlife Resources Commission ICMR Contribution Series, NO. ICMR-92-06
East Carolina University