Cheakamus River Water License Requirements ... - BC Hydro

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Cheakamus River Benthic Community Monitoring, Progress Report 19 Golder Associates who, with people of the Squamish Nation, are working on stranding studies downstream of Daisy Dam (Golder 2009). Guts from fish that were caught during electrofishing in November 2008 and died during processing were removed from the body cavity, sliced open, and preserved in 10% formalin in sealed Whirlpack plastic bags. In the lab, bag contents and organisms in the gut and stomach were washed into a microscope tray. Under a dissecting microscope, biological material was identified to the lowest reliable taxon and counted. Head counts were used for the enumeration of partly digested animals. These data are presently in spreadsheets awaiting upload to the database. A second set of samples consisting of coho and steelhead fry and parr is presently being collected by Josh Korman as part of electroshocking for estimates of juvenile salmonid population size in reaches downstream of the canyon. Once received, those samples will be cued for enumeration. No further stomach samples will be accessed under terms of the present contract for benthic community monitoring. Later in 2009 and as part of final analyses in 2010, the stomach content data will be compared to benthic invertebrate assemblages to determine similarities between food produced in the Cheakamus River and organisms ingested by salmonid populations. 3.7 11BData Analysis and Modeling All raw data acquired from the summer and winter sampling is awaiting upload to an Access database that is presently under development (see Section 3.9). Once all data from the present field and lab work and past data are uploaded, standard queries will be used to access specific data for statistical analysis and modeling. Exploratory data analyses may proceed before all data is compiled but final data analysis and modeling is expected to proceed in February – April 2010. Statistical analysis and modeling as outlined in Section 1 is expected to proceed in two steps with some modification depending on findings along the way. Cluster analysis and ordination techniques (i.e. multidimensional scaling (MDS)) will be used to identify groups of samples based on the Bray Curtis measure of similarity. These groups may correspond to gradients downstream of the dam, time course change in composition and abundance of invertebrates, or both. A subsequent analysis called SIMPER, in Primer software (Clarke and Gorley 2006), will reveal what taxa are most important in defining similarities within sample groups and dissimilarities among sample groups. Those taxa will be considered key indicators of change in habitat attributes, including flow, in the Cheakamus River. The indicators may include single taxa or combinations of taxa (e.g. all mayflies or mayflies plus stoneflies plus caddisflies). Discriminant function analysis (DFA) run in Systat v11 (Systat 2004) or BEST run in Primer will then be used to examine what habitat attributes are most important in discriminating the sample groups defined by clustering and ordination. DFA produces a model that can be used to determine what assemblage of organisms would be expected Limnotek/InStream November 2009
Cheakamus River Benthic Community Monitoring, Progress Report 20 for a given set of habitat attributes. BEST finds correlations between a sample matrix of biological data and a matrix of habitat attributes to identify most important habitat variables that are correlated with variation in biological assemblages. If flow or some metric of flow (e.g. coefficient of variation of flow, maximum or minimum flow during a sampling series, mean flow, etc.) is one of the discriminating variables, the second modeling step will proceed. A regression model will be produced to show change in abundance or biomass of a biological indicator as a function of discriminating variables found from the DFA or BEST analyses. In this way the modeling will allow exploration of shifts in the complete invertebrate assemblage and thus river health with amendment of flow and related attributes and it will support analysis of relative change in key biotic indicators or performance measures (an invertebrate metric) as a function of flow or related attributes. Most importantly, the analyses will indicate the relative importance of flow in determining river health as indicated by benthic invertebrate assemblages. At present, periphyton biomass and composition is expected to be used for descriptive purposes. Because periphyton is responsive to nutrient fluxes in the river, those data will be used to examine temporal and spatial shifts in trophic state. Assessment of trophic state in combination with the invertebrate modeling will be an ideal combination for describing health of the Cheakamus River. 3.8 12BPerformance Measure Development Performance measures are defined as biological indicators of river condition. These indicators will be assemblages or individual taxa of benthic invertebrates that are known to reflect change in river health. Sometimes these indicators are called “metrics” (Karr and Chu 1999). We will call them performance measures (PM) to maintain consistency with WLR terminology. PMs will be developed using the statistical procedures outlined in Section 3.7. Briefly, SIMPER (Clarke and Gorley 2006) will reveal what taxa are most important in defining similarities within sample groups and dissimilarities among sample groups that are defined by clustering and ordination. Those taxa will be considered PMs. They will be key indicators of change in habitat attributes, including flow in the Cheakamus River. PM development will occur at the time of final statistical analyses in February – April 2010. 3.9 13BReporting and Database Compilation Following submission of this progress report, a draft project report is expected to be submitted on May 31, 2010 and a final report on July 31, 2010. In the interim, short progress notes distributed by email will be used to inform contract authorities that key Limnotek/InStream November 2009
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