1. SWAMP Team Members Contact Information Karen Taberski: Ktaberski@waterboards.ca.gov, 510-622-2424, Nelia White: NWhite@waterboards.ca.gov, 510-622-2480 Leslie Perry: Lperry@waterboards.ca.gov, Kim Harrison: Kmharrison@waterboards.ca.gov, Arnie Thompson: Athompson@ waterboards.ca.gov, and Matthew Cover: Mcover@waterboards.ca.gov Seasonal Water Temperature Study – Summer 2005 Surface Water Ambient Monitoring Program (SWAMP) – SF Bay RWQCB SWAMP Program Overview and Goals SWAMP is a statewide surface water quality monitoring program implemented in the Bay Area by the San Francisco Bay Regional Water Quality Control Board. The state established SWAMP in 2000 at the urging of a public advisory group representing citizens, land managers, environmentalists, industries, cities, and farmers. SWAMP facilitates science-based regulatory decision-making. 20 21 22 23 24 25 26 27 28 Poster prepared by Arnie Thompson, SWAMP Stations For Temperature Study Maximum recorded temperatures in west Marin were higher for the full summer (June through October) 2005 than for snapshots taken August 1-13 and 16-21, 2005 and 2002. The highest water temperatures in 2005 occurred on or near July 23. Despite the average air temperature at the Bear Valley Visitor Center in Pt. Reyes during Aug. 1-13 2002 being warmer by 1.4° C (NPS data) than the same dates in 2005, the 2002 water temperature snapshot recorded cooler maximum temperatures. Results show that long term monitoring has a better chance of capturing high temperatures than does short term monitoring. Reducing the number of measurements per watershed from 7 to 10 to two or three would free up resources to monitor additional watersheds. Results in the Wildcat Creek watershed showed that more urbanized, lower canopy cover sites toward the bottom of the watershed (BOTW) were generally close in temperature. These BOTW sites exhibited higher temperatures than parkland sites higher in the watershed. One BOTW urbanized site plus one well-chosen upstream site with average canopy cover may give us a representative view of this watershed. Weighting the HOBO with common hardware keeps it in place and on the bottom. Body of HOBO Water Temp Pro hidden, but sensor exposed, in Lagunitas Creek. Water Temperature Sensors at Work Matt Graul of East Bay Parks testing his chest waders. Amy Burgard measuring canopy cover. Arnie Thompson crimping HOBO temp sensor onto anchor. Terri Fashing measuring pool depth. Do Runs and Pools Exhibit Different Temperature Profiles? Pool and run temperatures in Lagunitas Creek at Five Brooks tracked closely during mid July through late August, the hottest time of year with the highest water temperatures. Temperatures diverged slightly in late summer, likely due to low flows in runs. Pool and run temperatures at Nicasio diverged considerably as the run dried up in late summer. In shallow deployments, HOBO should be checked and relocated if necessary to ensure continuous submersion. MWAT – Maximum Weekly Average Temperature. Defined as the highest 7-day moving average of equally spaced water temperature measurements for a given time period. A study on the Mattole River in Northern California showed that Coho salmon (Oncorhynchus kisutch) were in very low abundance when MWAT exceeded 16.8 C (Welsh et al. 2001 ). Evaluating Salmonid Habitat with MWATs SWAMP team in action Design Considerations Evaluate SWAMP Year 1 (measured in 2002) temperature exceedances: revisit some sites, establish new monitoring sites Sample for the duration of the dry season (June – October) Test deployment and retrieval procedures Key Questions Would an extended time series (full season) catch more potential problem temperatures than a 6 – 14 day snapshot? Can we reduce the number of sampling sites per watershed, allowing us to monitor more watersheds? Do pools and riffles in our study area exhibit significantly different temperature profiles? Do these creeks provide good salmonid habitat? Conclusions When it comes to monitoring, longer is better. Longer monitoring periods increase the opportunity to catch edge conditions that threaten aquatic life. Monitoring stations with similar physical characteristics and/or stations with spatial auto-correlation may result in redundant data collection. Reducing the number of stations per watershed in order to monitor more watersheds may be desirable in many cases. Creeks in Region 2 exceeded MWATs of 16.8° C. Data with exceedances should be inspected closely for duration of high temperature and fast rate of change of temperature. Long Term Monitoring v. Snapshot Monitoring Fewer Sites Per Watershed Reference: Welsh, Hartwell H., Garth R. Godgson, Bret C. Harvey and Maureen Roche. 2001. Distribution of juvenile Coho salmon in relation to water temperatures in tributaries of the Mattole River, California. North American Journal of Fisheries Management 21:464-470.