교육데이터 활용•지원 서비스

Data collection, along with hydraulic and fluvial egg transport modeling, were completed along a 70.9-mile reach of the Ohio River between Markland Locks and Dam and McAlpine Locks and Dam. Data were collected during two surveys: October 27–November 4, 2016, and June 26–29, 2017. Water-quality data collected in this reach included surface measurements and vertical profiles of water temperature, specific conductance, pH, dissolved oxygen, turbidity, relative chlorophyll, and relative phycocyanin. Streamflow and velocity data were collected simultaneously with the water-quality data at cross sections and along longitudinal lines (corresponding to the water-quality surface measurements) and at selected stationary locations (corresponding to the water-quality vertical profiles). The data were collected to understand variability of flow and water-quality conditions relative to simulated reaches of the Ohio River and to aid in identifying parts of the reach that may provide conditions favorable to spawning and recruitment habitat for bighead carp (Hypophthalmichthys nobilis). A copy of an existing hydraulic model of the Ohio River was obtained from the National Weather Service and used to simulate hydraulic conditions for four different streamflows. Streamflows used for the simulations were selected to represent a range of conditions from a high-streamflow event to a seasonal dry-weather event. Outputs from the hydraulic model were used as input to the Fluvial Egg Drift Simulator (FluEgg) along with a range of five water temperatures observed in water-quality data and four potential spawning locations to simulate the extents and quantile positions of developing bighead carp, from egg hatching to the gas bladder inflation stage, under each scenario. A total of 80 simulations were run. Results from the FluEgg scenarios (which include only the hydraulic influences on survival that result from settling, irrespective of mortality from other physical factors such as excess turbulence, or biological factors such as fertilization failure, predation or starvation) indicate that the majority of the eggs will hatch, about half will die, and a quarter of the surviving larvae will reach the gas bladder inflation stage within the modeled reach. The overall average percentage of embryos surviving to the gas bladder inflation stage was 13.1 percent. Individual simulations have embryo survival percentages as high as 49.1 percent. The highest embryo survival percentages occurred for eggs spawned at a streamflow of 38,100 cubic feet per second and water temperatures of 24°C to 30°C. Conversely, embryo survival percentages were lowest for the lowest and highest streamflows regardless of water temperature or spawn location. Under low water temperature, high-streamflow conditions, some of the eggs did not hatch nor did the larvae reach the gas bladder inflation stage until passing beyond the downstream model domain. While the final quantile positions of the eggs and larvae beyond the downstream model domain are unknown, the outcomes still provide useful information.