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Project 5— Supplemental Water Temperature Data Collection <br />Need for Project <br />There is uncertainty regarding the degree of nearshore warming that will occur during the FSEF. <br />Korman and others (2006) found that the amount of nearshore warming increased slightly in September <br />relative to August, despite cooler air temperatures, because discharge volume and daily fluctuations <br />were lower in September. No nearshore warming occurred in October because average daily air <br />temperatures were comparable to water temperatures. However, temporal changes in nearshore warming <br />may differ during steady flows relative to what Korman and others (2006) observed during fluctuating <br />flows. The Physical Sciences and Modeling Program is developing a 2 -13 model that can be used to <br />predict water temperatures in nearshore environments. But this model cannot be parameterized for <br />steady flows in the fall because data are lacking. Detailed water temperature data will also be critical for <br />interpreting data from the nearshore ecology project. <br />If steady flows in September and October 2008 through 2012 do not strongly benefit humpback chub, it <br />may be because nearshore warming is minimal at this time of year. If this is the case, we suspect <br />managers would consider evaluating steady flows during the summer months when there is greater <br />potential for nearshore warming (Grand Canyon Monitoring and Research Center, 2008). Thermal infra- <br />red imagery collected in June 2000 during the LSSF provide rigorous quantitative data on the degree of <br />nearshore warming that can occur in June during steady flows of 8000 cfs. However, because these <br />same data have not been collected during fluctuating operations at.the same time of year, it is difficult to <br />put these data into context. That is, it is unclear whether nearshore habitat with warm water temperature <br />is gained during steady flows relative to fluctuating flows and if so, how much? <br />Scope of Work 1 <br />We propose deploying arrays of water temperature thermistors below the Little Colorado River <br />confluence (RM 61) from July 2010 through October 2010 in at least one of each of the different <br />shoreline habitat types the nearshore ecology project is evaluating. In addition, we will deploy <br />thermistors to monitor mainstem. temperature at the upstream and downstream boundaries of the <br />nearshore ecology study reach. These data would be used to determine the degree of nearshore warming <br />that occurs during steady flows in September and October and also to parameterize and calibrate the 2- <br />dimensional temperature model that the physical sciences group is developing. Deployment and <br />maintenance of thermistors would be done in collaboration with the nearshore ecology project, as they <br />will also be a primary user of these data. Thermistors would be deployed on the July 2010 nearshore <br />ecology trip and retrieved on the October 2010 trip. <br />This project will also include analysis and reporting on mainstem and nearshore temperature data that <br />were collected at up to 20 different locations from 2007 to 2010. <br />Budget <br />Biological Science Technician (GS -7- temporary): $20,000 <br />31 <br />