FISH TISSUE Sample Clauses

FISH TISSUE. The objectives of the fish monitoring are described in Section 1.3. The present section describes the analyses that will be conducted to address those objectives. Specifically, the June 2017 letter from the SFBRWQCB: Questions to be resolved: • What is the temporal trend in fish tissue mercury concentrations in remediation effectiveness indicators in Lake Almaden, ▇▇▇▇▇▇▇▇▇, Almaden, and ▇▇▇▇▇▇ Reservoirs, Alamitos and ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, and the ▇▇▇▇▇▇▇▇▇ River? • Is there a temporal trend in fish tissue mercury concentrations at reference sites, and if so, how does it inform interpretation of remediation effectiveness indicators? The fish tissue data to be included in the annual reports will include those data collected by the Tetra Tech/WRA team and those fish tissue results concurrently obtained from the District’s reservoir sampling program. The Water Board anticipates collecting additional fish mercury data from both Stevens Creek and Lexington Reservoirs in 2019. These data will be included in the annual report if fish tissue sampling is conducted by WRA in creeks during 2019. Otherwise, those data will be included in the District’s biennial report. The first step in analyzing the data on temporal changes in fish tissue concentrations will be to plot the data. All individual fish tissue data will be tabulated and plotted, including data collected for the TMDL staff report and data from Cycle 1. These graphs will allow a visual assessment of any potential trends as well as providing an estimate of the variability associated with fish tissue concentrations of mercury. Several plot types will be used to assess the mercury concentrations in fish tissue. Typical plots will include: • Box-and-whisker plots of tissue mercury concentration by each survey location for the survey year. • Scatter (x-y) plots of individual fish mercury concentrations for each stream sampling point and reservoir against time. • Fish tissue mercury concentrations will be plotted against fish length for each sampling location to assess the effect of length on concentration. Analysis of Variance (ANOVA) will be used to test for differences between survey locations, or between years at a given location. If a relationship between fish length and mercury concentration is evident, or fish lengths between samples are different, an analysis of covariance (ANCOVA) will be conducted to remove the effect of fish length on the results. The analyses will include an evaluation of the distributio...