Browsing by Author "Mosey, Britney"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Culvert Length and Interior Lighting Impacts to Topeka Shiner Passage
    (Minnesota Department of Transportation, 2017-11) Kozarek, Jessica; Hatch, Jay; Mosey, Britney
    Culverts can act as barriers to fish passage for a number of reasons including insufficient water depth or excess velocity. In addition, concern is being raised over behavioral barriers where culvert conditions elicit an avoidance response that deters or slows fish movement. Long culverts can block sunlight creating a potential behavioral barrier as fish approach a long, dark culvert. Scant information exists on low light as a potential barrier to fish passage, particularly with warm water species, such as the federally endangered Topeka Shiner. As some older culverts are being replaced with longer total lengths to improve safety by extending the culvert through reengineered road embankments, information is needed to 1) determine when and if light mitigation strategies are necessary, and 2) to design appropriate light mitigation strategies if necessary. Based on literature review, field monitoring, and laboratory experiments, the effect of light on fish passage for Topeka Shiner and other small prairie stream fish was indiscernible. Therefore, no light mitigation for large box culverts (up to 150 feet in length) can be recommended for similar fish communities. Culverts that are very long or have very small openings may benefit from additional light.
  • Thumbnail Image
    Item
    Light Levels, Long Box Culverts, And The Movements Of Prairie Stream Fishes, Including The Endangered Topeka Shiner
    (2017-05) Mosey, Britney
    Many culverts physically impede fish movement by altering flow, depth, turbulence, and sediment. Longer culverts may act as behavioral barriers by reducing ambient light levels. Movement within a stream is necessary to complete important life stages, maintain genetic diversity, and ultimately prevent extirpation. I evaluated light levels and fish movement in three long box culverts and corresponding control stream reaches in Southwestern Minnesota. The area has been denoted as critical habitat for the federally endangered Topeka Shiner Notropis topeka. I marked 18,963 fish, including 456 Topeka Shiner, and recaptured 1,874, including 46 Topeka Shiner during multiple mark and recapture events. Many fishes, including Topeka Shiner passed through each culvert; however, the probability of fish movement decreased as the culvert length increased and ambient light levels decreased. The probability was significantly less than corresponding control areas for the two longest and darkest culverts. The probability of movement was reduced in Cyprinidae (most abundant family), as well as the four most abundant species. Subsequent laboratory studies using captive-raised Topeka Shiner and wild-caught Fathead Minnow in a flume were conducted to evaluate light levels while controlling for other variables: velocity, water depth, and length of passage. Light alone did not account for significant differences in the number of fish to select a shaded or an unshaded passageway or the speed at which they approached and moved through the passageways under the laboratory settings. Mitigation of light levels may not be necessary when designing and implementing culverts, but synergistic relationships with other possible barriers (velocity, water depth, habitat within culvert, and length and dimensions of culvert) are unknown and need to be explored.