ScholarWorks@UA is University of Alaska's institutional repository created to share research and works by UA faculty, students, and staff

  • Population characteristics of lake trout in Walker Lake, Gates of the Arctic National Park and Preserve, Alaska

    Adams, Francis Jeffrey (1990-05)
    The population of lake trout in Walker Lake, southern Brooks Range, was investigated during summers. 1987 and 1988. Adults were most abundant at stream mouths after ice-out. Juveniles were most abundant in pelagic areas. Fingerlings preferred stream mouths. Ages ranged from 5 to 26 years. Lengths ranged from 203 to 924 mm; weights from 83 to 8,500 g. Both sexes had similar condition and matured at age 12. Fecundity increased with length and age. Females spawn every other year. Comparisons of growth curves and fecundity- at-length curves among populations in various Alaskan lakes suggested that lake trout in Walker Lake have not experienced heavy exploitation. The lake trout population in Walker Lake should be monitored in the future through angler surveys and selected studies of life history.
  • Glacier runoff influences biogeochemistry and resource availabilityin coastal temperate rainforest streams: Implications for juvenile salmon growth

    Fellman, Jason B.; Bellmore, J. Ryan; Johnson, Connor; Dunkle, Matthew R.; Hood, Eran (Association for the Sciences of Limnology and Oceanography, 2022-10-01)
    Meltwater contributions to watersheds are shrinking as glaciers disappear, altering theflow, temperature, andbiogeochemistry of freshwaters. A potential consequence of this landscape change is that streamflow patternswithin glacierized watersheds will become more homogenous, potentially altering the capacity of watersheds tosupport Pacific salmon. To assess heterogeneity in stream habitat quality for juvenile salmon in a watershed inthe Alaska Coast Mountains, we collected organic matter and invertebrate drift and measured streamwater phys-ical and biogeochemical properties over the main runoff season in two adjacent tributaries, one fed mainly byrain and the other partially by glacier ice/snowmelt. We then used bioenergetic modeling to evaluate how tem-poral patterns in water temperature and invertebrate drift in each tributary influence juvenile salmon growthpotential. Across the study period, average invertebrate drift concentrations were similar in non-glacierizedMontana (0.33 mg m 3) and glacier-influenced McGinnis Creeks (0.38 mg m 3). However, seasonal patterns ofinvertebrate drift were temporally asynchronous between the two streams. Invertebrate drift and modeledfishgrowth were generally higher in McGinnis Creek in the spring and Montana Creek in the Summer. For juvenilesalmon, tracking these resource asynchronies by moving between tributaries resulted in 20% greater growththan could be obtained within either stream alone. These results suggest that hydrologic heterogeneity withinwatersheds may enhance the diversity of foraging and growth opportunities for mobile aquatic organisms,which may be essential for supporting productive and resilient natural salmon runs.
  • Watershed Classification Predicts Streamflow Regime and Organic Carbon Dynamics in the Northeast Pacific Coastal Temperate Rainforest

    Giesbrecht, Ian; Tank, Suzanne; Frazer, Gordon W.; Hood, Eran; Gonzalez Arriola, Santiago G.; Butman, David E.; D'amore, David V.; Hutchinson, David; Bidlack, Allison Lynn; Lertzman, Ken P. (American Geophysical Union, 2022-01-28)
    Watershed classification has long been a key tool in the hydrological sciences, but few studies have been extended to biogeochemistry. We developed a combined hydro-biogeochemical classification for watersheds draining to the coastal margin of the Northeast Pacific coastal temperate rainforest (1,443,062 km2), including 2,695 small coastal rivers (SCR) and 10 large continental watersheds. We used cluster analysis to group SCR watersheds into 12 types, based on watershed properties. The most important variables for distinguishing SCR watershed types were evapotranspiration, slope, snowfall, and total precipitation. We used both streamflow and dissolved organic carbon (DOC) measurements from rivers (n = 104 and 90 watersheds respectively) to validate the classification. Watershed types corresponded with broad differences in streamflow regime, mean annual runoff, DOC seasonality, and mean DOC concentration. These links between watershed type and river conditions enabled the first region-wide empirical characterization of river hydrobiogeochemistry at the land-sea margin, spanning extensive ungauged and unsampled areas. We found very high annual runoff (mean > 3,000 mm, n = 10) in three watershed types totaling 59,024 km2 and ranging from heavily glacierized mountain watersheds with high flow in summer to a rain-fed mountain watershed type with high flow in fall-winter. DOC hotspots (mean > 4 mg L−1, n = 14) were found in three other watershed types (48,557 km2) with perhumid rainforest climates and less-mountainous topography. We described four patterns of DOC seasonality linked to watershed hydrology, with fall-flushing being widespread. Hydro-biogeochemical watershed classification may be useful for other complex regions with sparse observation networks.
  • Datasets for journal article: Contribution of fresh submarine groundwater discharge to the Gulf of Alaska

    Russo, Aeon (2023-03-08)
    *Source code with initial conditions for LPRM model (R file) *Input and output files for LPRM and GLDAS models (.csv files) *ESRI map package (.aprx file) that allows subsequent users to recreate Figures 3 and 5 using ArcGIS Pro

    Ban, Xuegang (Jeff); Abramson, Daniel; Zhang, Yiran; Lukins, Sarah; Goodrich, Kevin; Mirante, Andrea; Lambert, Rachel; Yankey, Mykala (2023-02)
    Transportation and traffic safety is a primary concern within Rural, Isolated, Tribal and Indigenous (RITI) communities in Washington State. Emerging technologies such as connected and autonomous vehicles, sensors and drones have been tested and developed to improve traffic safety, but these advances have largely been limited to urban areas. This project identified opportunities and challenges of adopting drone technologies in RITI communities, and explored context-sensitive applications to traffic safety and related goals. In three phases, the team conducted community workshops, online surveys and other outreach activities with state and county agencies responsible for emergency management and crisis response in coastal Tribal and non-tribal communities; a planning studio and Comprehensive Plan Update for the City of Westport and its surrounding South Beach community straddling two rural counties and including the Shoalwater Bay Indian Tribe; and a pilot educational program with the School District that serves it. To be effective in rural contexts, adoption of drone technology depends on a broadening of local skill development and needs to target diverse community goals. In short, it needs to be broadly embedded in the community. Taking this sociotechnical approach, we focused on long-term workforce development and designed and implemented an after-school program (October 2021 – June 2022) for Ocosta Junior High School students. The course taught students how to assemble and pilot drones and apply them to a variety of practical needs including public works inspection, search and rescue, and environmental monitoring of coastal flooding.

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