Central Alaska Network flowing waters monitoring program: 2010 annual report

Simmons, Trey

The 2010 field season marked the fifth year of development of the flowing waters portion of the Central Alaska Network (CAKN) Inventory and Monitoring Program, also known as the Vital Signs Program. Data collection occurred in both Wrangell-St. Elias National Park and Preserve (WRST) and in Denali National Park and Preserve (DENA). The purposes of the study were to 1) continue to refine field protocols and logistics related to the collection of relevant data in DENA and WRST streams and rivers; 2) implement a multi-panel sampling design in WRST; 3) begin sampling GRTS-selected synoptic sites in DENA, and 4) implement the long-term flowing water monitoring program. The data collected included biological (benthic macroinvertebrate and diatom samples, fish identity and size, riparian vegetation type), physical (channel geometry, substrate, etc.) and chemical (collected in situ as well as in water samples for later analysis) information. Data were collected during a total of 73 site visits across the two park units; 42 unique sites were sampled. Continuously recording temperature data loggers were deployed at 15 sites across the network. Near-record flooding occurred in late July in the Nabesna area. Very high flows led to the loss of two pressure transducers in Jack Creek, as well as causing substantial channel change in some streams. In DENA, another four previously unreported macroinvertebrate taxa were documented, bringing the four-year total of newly-documented taxa to 42. Network-wide, the program has now documented 150 unique macroinvertebrate taxa and 440 diatom species. Of these, nine invertebrate taxa and 44 diatom taxa were first reported in 2010. The fourth year of data collected from streams involved in the Long-Term Ecological Monitoring program in DENA confirmed earlier indications that there are incompatibilities between data collected using LTEM methodologies and those collected using CAKN methodologies. Some analyses were conducted on the year-to-year variability of water chemistry and macroinvertebrate data collected since 2006. A substantial portion of the temporal variation in water chemistry, at least for some streams and some constituents, appeared to be attributable to differences in discharge among sampling events. 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. Invertebrate and environmental data collected in 2010 were used to refine the preliminary RIVPACS predictive biological assessment model that was constructed for network streams last year. The addition of new data improved the performance of the model, with precision and bias of the models comparable to that seen in other large-scale models.

Central Alaska Network flowing waters monitoring program: 2010 annual report

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