Least Chub Habitat Sensitivity Study

This is a Notice of Intent to award a Grant to State of Utah, Department of Natural Resources, for the purpose of conducting a habitat sensitivity study for the Least Chub. Analyze relationships of groundwater levels, precipitation, and evapotranspiration to the volume and surface area of aquatic habitat. Assess how spring discharge rates are related to variation in the volume of water and the depth of sediments in sampling units. Analyze relationships of solute concentrations in the sampling units to groundwater levels, spring discharge rates, precipitation, and evapotranspiration. Provide a statistical model for predicting variation in the surface area of aquatic habitat in the Leland Harris Spring Complex based on variation of groundwater levels, precipitation, and estimated rates of evapotranspiration. Provide a statistical model for predicting variation in the volume of aquatic habitat in the Leland Harris Spring Complex based on variation of groundwater levels, precipitation, and estimated rates of evapotranspiration. Provide Color-coded maps showing predicting amounts of surface water (extent and depths) under multiple scenarios for reductions in groundwater levels. Evaluate Least Chub habitat requirements on a seasonal basis (considering both breeding habitat and core habitat), and assessment of how amounts of suitable habitat are likely to change with changes in spring discharge rates (which influence solute concentrations, the amount of ice-free habitat in the winter, sediment transport, and is hypothesized to influence surface water levels) and precipitation (which influences amounts of surface water in pools). Provide a summary assessment of relationships between groundwater levels and the amount of suitable habitat for Least Chub at the Leland Harris Spring Complex. Past habitat data indicate that water depth is positively related to the presence and abundance of Least Chub during relatively dry times of the year (e.g., late summer), so the amount of water of adequate depth will be one of the dependent variables considered in this assessment. Other variables that will be considered include solute concentrations and interconnectivity of bodies of water.