These data were used to examine drivers behind changes in water temperature downriver of dams across the western U.S. from 1995-2015 and the influence of such changes on rainbow trout recruitment and rainbow and brown trout adult length. First, we linked reservoir storage capacity and dam size to the warmest monthly water temperature per water year (WY) to assess the influence of low storage capacity (shallow reservoirs) on downstream water temperature. We then took results from previously published Generalized Linear Mixed Models (GLMM) that assessed the influence of physical and biological predictors (e.g., flow, trout density, reservoir metrics) on trout recruitment and adult size and added mean annual, maximum annual, and minimum annual water temperature and the warmest and coldest month in each WY to the dataset. This permitted an evaluation of the relative importance of water temperature on trout population dynamics relative to other physical and biological predictors. Detailed methods and results are reported in the manuscript associated with this data publication.

Juvenile coho salmon seek slow velocity areas as rivers rise during storm events. Studies have shown significant increase in juvenile coho salmon growth and survival when they have access to slow water refuge in off-channel ponds during these storms. In addition, off channel features also provide habitat for several other animals including reptiles, amphibians and numerous bird species. In 2014, Humboldt Redwood Company (HRC) identified an abandoned overflow channel that had the potential to become off channel habitat in Lawrence Creek located within the Van Duzen River watershed and asked the National Marine Fisheries Service (NMFS) to partner on the project. NMFS conducted the physical surveys, created the design, and a small competitive internal grant from NOAA provided funding for part of the project construction. HRC worked on the permits, donated heavy equipment and operators as well as several large logs with root wads to build the instream structures.

We used snorkel surveys in the Elwha River, conducted in consecutive years before (2007, 2008) and after (2018, 2019) dam removal to assess changes in fish distribution and density. In total, we counted 54,616 Chinook Salmon, Bull Trout, Steelhead, and trout (Rainbow Trout and Coastal Cutthroat Trout combined) in 22 common reaches spanning 65 river kilometers. The occupancy of juvenile Chinook Salmon, Coho Salmon, and trout was also assessed following dam removal.

We used snorkel surveys in the Elwha River, conducted in consecutive years before (2007, 2008) and after (2018, 2019) dam removal to assess changes in fish distribution and density. In total, we counted 54,616 Chinook Salmon, Bull Trout, Steelhead, and trout (Rainbow Trout and Coastal Cutthroat Trout combined) in 22 common reaches spanning 65 river kilometers. The occupancy of juvenile Chinook Salmon, Coho Salmon, and trout was also assessed following dam removal.

Hourly counts of all fish species observed at the Andreafsky Weir. Data are derived from weir video feed for available years 2015-2023. Counts were done hour by hour for 24 hours a day unless maintenance was required or conditions disrupted the video feed. NA delineates times in which the video feed was not active while 0 delineates that no fish were counted for that hour. All species have been standardized and counted every year since the implementation of the video feed.

Hourly counts of all fish species observed at the Andreafsky Weir. Data are derived from weir video feed for available years 2015-2023. Counts were done hour by hour for 24 hours a day unless maintenance was required or conditions disrupted the video feed. NA delineates times in which the video feed was not active while 0 delineates that no fish were counted for that hour. All species have been standardized and counted every year since the implementation of the video feed.

The Strait of Juan de Fuca Intensively Monitored Watershed (IMW) began in 2004 to test the watershed-scale response of steelhead and coho salmon to watershed restoration. The Strait IMW includes two treatment watersheds (East Twin River and Deep Creek) and one control watershed (West Twin River). Restoration treatments included LWD placement, road and culvert removal, off-channel habitat creation, and riparian planting. Monitoring of physical habitat as well as coho and steelhead parr densities began in 2004 using the EPA’s EMAP site selection and sampling protocols. Smolt and adult monitoring predates the IMW program and began as early as 1998 in some watersheds. Preliminary results suggest an increase in pool habitat and small increases in steelhead adults and smolts in East Twin River, as well as adult coho in Deep Creek. PIT tagging has revealed a large outmigration of age-0 coho in the fall that contributes to the adult return, stream swapping by juveniles, and varying return times for coho adults. Current research has answered a portion of our original questions and has raised new ones. Restoration treatments were completed fairly recently or are still in progress. As habitat typically does not respond immediately to treatment, additional years of monitoring are needed to determine watershed-scale fish response. Moving forward, analysis of otoliths to validate PIT tag data and new restoration methods such as carcass or nutrient enhancement may be merited. PIT tagging and habitat data. Includes fish weight, length, location, and PIT tag number. Habitat data includes wood measurements and stream surveys.

This dataset contains length, weight, energy density, and isotope values of fish collected in northwest Alaskan rivers during summer and fall 2015-2019.

This dataset contains length, weight, energy density, and isotope values of fish collected in northwest Alaskan rivers during summer and fall 2015-2019.

eDNA-based spatiotemporal distribution data (occupancy model format) for rainbow trout (Oncorhynchus mykiss) and bull trout (Salvelinus confluentus) within the Bruneau-Jarbidge Rivers Wilderness in southern Idaho and northern Nevada, USA. Data also include stream discharge and stream temperature data for each site. All data were collected between October 2015 and September 2016.