DOI: 10.5061/dryad.8sf7m0d29
title: Data from: Long-term changes in the juvenile Sockeye salmon rearing capacity of the Chignik lakes watershed

description: 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.
description: # Data from: Long-term changes in the juvenile Sockeye salmon rearing
 capacity of the Chignik lakes watershed Dataset DOI:
 [10.5061/dryad.8sf7m0d29](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 (&lt; 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](mailto: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/m^2^. 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/m^2^ #### 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