This is a tabular data set containing age, sex, and length measurements of Inconnu sampled from the Yukon River and tributaries in Alaska between 1990 and 2018.

This is a tabular data set containing age, sex, and length measurements of Inconnu sampled from the Yukon River and tributaries in Alaska between 1990 and 2018.

Tabular datasets containing information pertaining to fish caught during trapping effort in the Deshka River between 2019 and 2024 to sample juvenile salmon. These data collected from the field are used to assess effort and were acquired using a Survey123 data acquisition application.

Tabular datasets containing information pertaining to fish caught during trapping effort in the Deshka River between 2019 and 2024 to sample juvenile salmon. These data collected from the field are used to assess effort and were acquired using a Survey123 data acquisition application.

Tabular datasets containing information pertaining to traps set in the Deshka River between 2019 and 2024 to sample juvenile salmon. These data collected from the field are used to assess effort and were acquired using a Survey123 data acquisition application.

Tabular datasets containing information pertaining to traps set in the Deshka River between 2019 and 2024 to sample juvenile salmon. These data collected from the field are used to assess effort and were acquired using a Survey123 data acquisition application.

Chinook Salmon (Oncorhynchus tshawytscha) are an important commercial, subsistence, and recreational fishery resource in Alaska, and recent population declines have resulted in closures of some Chinook Salmon fisheries. Research into environmental factors involved in the decline of salmon stocks has exposed information gaps regarding fine-scale freshwater habitat quality known to influence Chinook Salmon productivity. We developed spatially-explicit intrinsic habitat potential models for Chinook Salmon freshwater spawning and rearing life-stages based on geomorphic stream network attributes (e.g., gradient, mean annual flow, valley bottom width). Model predictions were applied to individual stream reaches and summarized across synthetic stream networks derived from high-resolution (5-meter) digital elevation models covering the Yukon River drainage west of the US-Canada border and the entire Kuskokwim River drainage (total stream length ~667,000 km across 1.3 million km2 area). Vector spatial datasets include unique reach contributing area (uRCA) and unique reach contributing area valley bottom (uRCA VB) polygons, and confluence to confluence streamline edges derived from the NetMap synthetic streamlines product. Tabular data includes a collection of stream attributes summarized by uRCA or uRCA VB polygons, and habitat model results derived from these stream attributes. See metadata records for individual data elements for a description of input sources, software environments, data quality, processing steps, and attribute information. Approximately 87,500 and 39,500 stream km were predicted to represent moderate to high (index scores 0.6-1.0) Chinook Salmon rearing and spawning habitat suitability, respectively. Our high-resolution, spatially explicit dataset provides many options for summarizing and visualizing habitat suitability across areal units (e.g., river basins, land management boundaries) and assessing the potential for high suitability habitats outside the known distribution of Chinook Salmon at scales useful for managers and the research community.

Chinook Salmon (Oncorhynchus tshawytscha) are an important commercial, subsistence, and recreational fishery resource in Alaska, and recent population declines have resulted in closures of some Chinook Salmon fisheries. Research into environmental factors involved in the decline of salmon stocks has exposed information gaps regarding fine-scale freshwater habitat quality known to influence Chinook Salmon productivity. We developed spatially-explicit intrinsic habitat potential models for Chinook Salmon freshwater spawning and rearing life-stages based on geomorphic stream network attributes (e.g., gradient, mean annual flow, valley bottom width). Model predictions were applied to individual stream reaches and summarized across synthetic stream networks derived from high-resolution (5-meter) digital elevation models covering the Yukon River drainage west of the US-Canada border and the entire Kuskokwim River drainage (total stream length ~667,000 km across 1.3 million km2 area). Vector spatial datasets include unique reach contributing area (uRCA) and unique reach contributing area valley bottom (uRCA VB) polygons, and confluence to confluence streamline edges derived from the NetMap synthetic streamlines product. Tabular data includes a collection of stream attributes summarized by uRCA or uRCA VB polygons, and habitat model results derived from these stream attributes. See metadata records for individual data elements for a description of input sources, software environments, data quality, processing steps, and attribute information. Approximately 87,500 and 39,500 stream km were predicted to represent moderate to high (index scores 0.6-1.0) Chinook Salmon rearing and spawning habitat suitability, respectively. Our high-resolution, spatially explicit dataset provides many options for summarizing and visualizing habitat suitability across areal units (e.g., river basins, land management boundaries) and assessing the potential for high suitability habitats outside the known distribution of Chinook Salmon at scales useful for managers and the research community.

Radio telemetry was used to determine the distribution, locate spawning sites, and evaluate the tagging response of wild Chinook salmon Oncorhynchus tshawytscha returning to a large, free-flowing river basin. A total of 2,860 fish were radio tagged in the lower Yukon River and tracked upriver. Fish traveled to spawning areas throughout the basin, ranging from several hundred to over 3,000 km from the tagging site. We found similar distribution patterns across years, suggesting that the major components of the return were identified. Most spawning fish were clustered in a number of principal tributaries, although small numbers of fish were located in other spatially-isolated areas. The cumulative contribution of these minor stocks was appreciable, making up 28-31% of the tagged sample. There was suggestive evidence of mainstem spawning in upper reaches of the basin. Large-scale elevation and physiographic data were useful in categorizing spawning areas, with most fish returning to relatively entrenched upland rivers. Fish were largely absent in lowland reaches characterized by meandering, low gradient, alluvial channels often associated with main river floodplains. The fish generally responded well to the capture, handling, and tagging procedures with most (2,790, 97.6%) resuming upriver movements, although the fish initially displayed a negative tagging response, with slower migration rates observed immediately after release. The duration of this response was relatively short (several days) and less severe as the fish moved upriver. The swimming speeds of radio-tagged fish after the initial delay were comparable to estimates for untagged fish, further suggesting that the capture, handling, and tagging methods used were relatively benign. Identifying the primary components of the run (including both major and minor stocks) and determining site-specific utilization patterns can fundamentally enhance salmon management in large river basins, and facilitate research and conservation efforts.

Tabular dataset containing age, sex, and length data for Chum, Chinook, and Sockeye salmon. Sex was determined externally using visual clues such as snout shape and size. Length was measured from fork to mid-eye with a measuring board to the closest 5 mm. Strata refers to the potion of the run the fish was sampled during. Strata data is based on the size of the population rather than date since the salmon run does not start on one specific date year by year. Scales were also taken and placed on a gum card for age assessment. One scale was taken for all sampled Chum salmon and three scales were taken for all sampled Chinook salmon.