Technical Work Group Meetings 2009

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' Glen Canyon Dam Technical Work Group Page 3 DRAFT Minutes of July 16 -17, 2008, Meeting Park" (Attachment 3a) and said it's under Goal 6 in the workplan. He then reviewed several posters (Attachment 3b) and identified what the program stored and what it meant in terms of looking at all the combined information. He encouraged people to look at the second poster as it depicts the best outcome of ' the computerized modeling. It looks at the 2002 overflight data that was used to produce the information and is broken up reach. Remote Sensing. Glenn Bennett said he wanted to talk about DASA which is line item D6. They did R &D building, the types of surface classification which gives coarseness or roughness all the way up to boulders. He said their basic full tool is to automate so it can be used over multiple years. There should be a method paper available by the end of the year. Glenn added that Reclamation is setting up a huge biological database and taking input from other agencies. The goal is to come up with a full dataset that goes across the agencies. It looks like a good start with BLM, BOR, NPS, FWS, etc., and he thinks GCMRC's program will contribute to their database. LSSF Workshop Update Matthew Andersen said in August 2007 a synthesis workshop was held to discuss the 2000 flows which were also referred to as the LSSF. This is in Goal 12. This has been done in a couple of stages and brings together the original workplan and those that have been completed. In the meantime, it was proposed to have two different workshops. The first of the workshops is scheduled for August 12 -14 and the emphasis will be on the physical and biological sciences. 1 � Workshop. u 1 GMCRC will provide a list of documents the TWG should review in preparation for the LSSF Rainbow Trout Diet/Predation Study. Mike Yard gave a PPT Presentation entitled, "Foraging Ecology of Nonnative Trout in the Colorado River, Grand Canyon Predation on Native Fishes and the Effects of Turbidity" (Attachment 4). He provided the following conclusions on rainbow and brown trout: Rainbow Trout Brown Trout Detect ability rather than food availability appear to explain Highly piscivorous, but the least abundant trout differences in rainbow spatial distribution and condition factors. Drift feeing appears to be an inadequate strategy for Brown trout distribution and condition are not providing daily rations correlated to increased turbidity High electivity for larger prey items Diet is not correlated with invertebrate drift availability Foraging strategy may shift from visual sight feeding to a Incidence of piscivory is correlated with prey more mobile, searching strategy under increased turbidity availability of native fish At high densities cumulative effects from piscivory may Incidence of piscivory is not influenced by exceed brown trout turbidity Brown trout use a mobile foraging strategy that includes a ibenthic feeding and piscivory. ' Q: 1 was wondering in the analysis you've done, can you help us in making tradeoffs and Mark's earlier question. There is a learning and research component. (Kubly) A: There are a number of information gaps that are not going to come out of this. It's really the brown that is the piscivorous one. It doesn't appear that they're independently reproducing. (Yard) C: Their recommendation was to keep the RBT population low. When they get high, they can have a negative effect. We were getting many fewer fish in the samples we were pulling in. (Andersen) : Kurt said a presentation on the native origin of rainbow trout would be put on the next TWG agenda. ' Near Shore Ecology /Fall Steady Flows. Matthew Andersen said GCMRC and others have been concerned about nearshore ecology and fall steady flows and possibly combining the two studies. In working with the cooperator, they realized it would be difficult to start that study and have a completed draft to NPS for