Alaska Sustainable Salmon Fund Project #52002: Climate warming effects on Chinook Salmon foraging conditions and growth ...

• Main Author: Neuswanger, Jason
• Format: Dataset
• Language: English
• Published: Dryad 2022
• Subjects: FOS Agriculture, forestry, and fisheries; Chinook salmon; Oncorhynchus tshawytsha; Alaska; Chena River; Fairbanks; Climate change; fish growth; salmon growth; salmonid; invertebrate drift; Volk; Yukon; Yukon river
• Online Access: https://dx.doi.org/10.5061/dryad.1vhhmgqvv; https://datadryad.org/stash/dataset/doi:10.5061/dryad.1vhhmgqvv

The Chena River hosts one of the largest populations of Chinook Salmon in the Alaska portion of the Yukon River drainage, which has recently experienced poor Chinook returns throughout. Past work suggests that these fish do poorly when they grow slowly due to cold, high-flow conditions during their first summer in the river as juveniles, and the population does well when juveniles experience warm, low-flow years and grow larger. Because high flow drives low water temperatures and vice versa, it was previously unclear to what extent each factor—flow and temperature—affects the fish population. We collected data to run foraging and bioenergetics models that simulate how flow and temperature affect growth. We invented two sampling devices, a suction pump to sample drifting prey and a computer vision system to measure the inedible debris that occupy most of a fish’s feeding effort. We combined our data with USGS and NOAA records to predict temperature, turbidity, prey, and debris on a daily basis throughout our ... : Temperature data were collected by placing Hobo data loggers at our study sites (see Study Site Map.png) for two years. We used a machine learning model in Mathematica (gradient-boosted trees) to predict water temperature at the USGS Two Rivers hydrograph (data available from USGS from late-2013 onward) based on streamflow, day-of-year, and air temperature at the Fairbanks airport. We then used that regression, streamflow, and air temperature as predictors for machine learning models (by the same method) to estimate daily temperature (degrees C) at all of our study sites from 1967 to present. Invertebrate drift data were collected using a suction pump as described in the associated Hydrobiologia publication: Neuswanger. J.R., Schoen, E.S., Wipfli, M.S., Volk, C.J., and Schoen, E.R. 2022. A suction pump sampler for invertebrate drift detects exceptionally high concentrations of small invertebrates that drift nets miss. Hydrobiologia (in press). DOI: 10.1007/s10750-022-04849-1. Juvenile Chinook salmon were ...