Data from: Long-term changes in the juvenile Sockeye salmon rearing capacity of the Chignik lakes watershed
Data files
Feb 12, 2026 version files 6.99 MB
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Juvenile_Sockeye_Length_Mass.csv
2.74 MB
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Lake_Temperatures.csv
3.92 MB
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README.md
2.32 KB
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Resident_Fish_Catch.csv
190.02 KB
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Zooplankton_Density.csv
135.05 KB
Abstract
Freshwater ecosystems respond rapidly to perturbations in climate, geomorphology, and population abundances. For migratory species in interconnected habitat networks, local habitat conditions can control the productivity of individual populations. Asynchronous variation in habitat quality can simultaneously stabilize ecological processes at broad scales but also complicate the understanding of ecosystem dynamics. We investigated habitat-specific trends in indicators of the rearing capacity for juvenile sockeye salmon in a remote watershed in Alaska over the last ~60 years. The motivation of this effort was to understand if the collapse of the local salmon fishery in 2018 could be traced to changes in habitat quality within the nursery watershed. Our analyses describe high variability in the habitat conditions across both spatial and temporal scales, yet do not suggest a decline in the overall sockeye salmon rearing capacity of the watershed. We observed increasing maximum water temperatures in a shallow lake but more stable conditions in a deep lake, an improvement in zooplankton prey resources in the deep lake, and increased juvenile sockeye salmon growth rates throughout the watershed. Although we detected no long-term decline in rearing habitat quality, there was a decrease in juvenile sockeye salmon abundance from 2013-2016, suggesting high early life stage mortality prior to the period of juvenile rearing leading up to the fishery collapse.
Dataset DOI: 10.5061/dryad.8sf7m0d29
Description of the data and file structure
Metadata for
Authors: C. Gammelin, D.E. Schindler
Title: "Long-term Changes in the Juvenile Sockeye Salmon Rearing Capacity of the Chignik Lakes Watershed"
Year: 2025
Journal: PLOS-ONE
Files:
- "Juvenile_Sockeye_Length_Mass.csv" : Length and mass for juvenile sockeye salmon (Oncorhynchus nerka) collected in the Chignik Lakes watershed, AK between 1961-2024.
- "Lake_Temperatures.csv" : Summer (June, July, August) Lake surface (< 10 m) water temperatures collected in the Chignik Lakes watershed, AK between 1929-2024.
- "Resident_Fish_Catch.csv" : Juvenile sockeye salmon (Oncorhynchus nerka), pond smelt (Hypomesus olidus), three-spine stickleback (Gasterosteus aculeatus), and nine-spine stickleback (Pungitius pungitius) catches in the Chignik Lakes watershed, AK between 1961-2024.
- "Zooplankton_Density.csv" : Zooplankton (Daphnia, Bosmina, cyclopoid copepod, and calanoid copepod) densities in the Chignik Lakes watershed, AK between 1961-2024.
Data Collection:
Data were collected by Cirque Gammelin (cirqug@uw.edu) and the University of Washington Alaska Salmon Program. Juvenile sockeye salmon and resident fish were sampled via townet. Fork length measured to the nearest mm and mass if taken to the nearest 0.1 g. Zooplankton densities were measured in 100s of individuals/m2. Methods are detailed in the associated article.
Files and variables
File: Zooplankton_Density.csv
Description:
Variables
- Lake: Lake sampled
- Date: mm/dd/yy
- Species: taxa
- Density: unit = 100s of individuals/m2
File: Resident_Fish_Catch.csv
Description:
Variables
- Lake: Lake sampled
- Year: yyyy
- Date: mm/dd/yy
- Species: common name
- Catch: number of inidviduals
File: Juvenile_Sockeye_Length_Mass.csv
Description:
Variables
- Lake: Lake sampled
- DateSampled: mm/dd/yy
- Length: unit = mm
- Mass: unit = g
File: Lake_Temperatures.csv
Description:
Variables
- Lake: Lake sampled
- Date: mm/dd/yy
- Depth: unit = m
- Temp: unit = Degrees Centigrade
