Central Alaska Network flowing waters monitoring program: 2011 annual report

Simmons, Trey

The 2011 field season marked the sixth year of development and implementation of the flowing waters portion of the Central Alaska Network (CAKN) Vital Signs Inventory and Monitoring Program and the first year in which data were collected in all three network parks — Wrangell-St. Elias National Park and Preserve (WRST), Denali National Park and Preserve (DENA) and YukonCharley Rivers National Preserve (YUCH). The program goals for 2011 were to 1) continue to refine field protocols and logistics related to the collection of relevant data in network streams and rivers, 2) implement a multi-panel sampling design in WRST and DENA, 3) begin sampling GRTS-selected synoptic sites in YUCH, and 4) implement the long-term flowing water monitoring program. The data collected included biological (benthic macroinvertebrate and diatom samples), physical (channel geometry, substrate size, etc.) and chemical (collected in situ as well as in water samples for later analysis of chemical constituents and stable isotopes) information. Data were collected during a total of 101 site visits at 43 unique sites across the three park units. Individual sites were visited anywhere from one to five times during the open-water season, although the full suite of data was not collected at every visit. Continuously recording temperature data loggers were deployed at 24 sites in DENA and WRST. Preliminary analysis of these data reveals considerable variation in temperature regime within and among streams, but no discernable trends. It was the fourth year of active-layer depth measurements and collection of continuous soil temperature data at the two Circumpolar Active Layer Measurement (CALM) plots established in WRST. In DENA, another seven previously unreported macroinvertebrate taxa were documented, bringing the five-year total of newly-documented taxa in that park to 50. Network-wide, the program has now documented 166 unique macroinvertebrate taxa and 460 diatom species. Of these, 16 invertebrate taxa and 20 diatom species were first documented in samples collected in 2011. The fifth year of data collected from streams involved in the Long-Term Ecological Monitoring (LTEM) program in DENA confirmed earlier indications that there are incompatibilities between data collected using LTEM methodologies and those collected using CAKN methodologies. Some preliminary analyses were conducted on the year-to-year variability of water chemistry and macroinvertebrate data collected since 2006. A substantial portion of within-site temporal variation in water chemistry appears to be attributable to differences in discharge among sampling events. Grouping sampling events by season substantially reduces this variation by partially accounting for differences in discharge, which is not typically measured at each sampling visit. Year-to-year variation in macroinvertebrate composition at most streams appears to be moderate by comparison, and nearly two thirds of the apparent variation is likely due to sampling error. No directional trends in invertebrate community composition were apparent at any of the 14 streams with at least three years of data. Invertebrate and environmental data collected in 2010 and 2011 were used to refine the preliminary RIVPACS predictive biological assessment model that was first constructed for network streams using data collected from 2006 to 2009. The addition of new data improved the performance of the model, with precision and bias of the mode

Central Alaska Network flowing waters monitoring program: 2011 annual report

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