Influence of Instream Physical Habitat and Water Quality on the Survival and Occurrence of the Endangered Cape Fear Shiner
Author:
Publisher:
Published: 2003
Total Pages:
ISBN-13:
DOWNLOAD EBOOKThe Cape Fear shiner Notropis mekistocholas is a recently described cyprinid fish endemic to the Cape Fear River Basin of North Carolina. Only five declining populations of the fish remain, and therefore, it has been listed as endangered by the U.S. Government. Determining habitat requirements of the Cape Fear shiner, including physical habitat and water quality, is critical to the species' survival and future restoration. This study integrated the sciences of toxicology and conservation biology, and simultaneously assessed ecosystem level influences of habitat (water and physical environments) on survival, growth, occurrence, and distribution of the Cape Fear shiner. I conducted an instream microhabitat suitability analysis among five sites on the Rocky and Deep rivers to (1) quantify Cape Fear shiner microhabitat use, availability, and suitability in extant habitats, (2) determine if physical habitat alterations are a likely cause of extirpation of the Cape Fear shiner at historical locations and if instream habitat is a limiting factor to occurrence and survival of the species in extant habitats and at potential reintroduction sites, and (3) estimate population density at selected extant sites. I used an in situ 28-day bioassay with captively propagated Cape Fear shiners to (1) determine if water quality is a limiting factor to the occurrence, growth, and survival of the Cape Fear shiner, (2) document habitat suitability by assessing inorganic and organic contaminants through chemical analyses and review of existing data, and (3) assess the protectiveness of water quality standards for primary pollutants based on comparisons of laboratory, field toxicity, and water chemistry data. Cape Fear shiners most frequently occupied riffles and velocity breaks (i.e., areas of swift water adjacent to slow water), moderate depths, and gravel substrates. They used habitat non-randomly with respect to available habitat, and habitat use was similar between post-spawning and spa.
