Restored off-channel pond habitats create thermal regime diversity and refuges within a Mediterranean-climate watershed

Cool-water habitats provide increasingly vital refuges for cold-water fish living on the margins of their historical ranges; consequently, efforts to enhance or create cool-water habitat are becoming a major focus of river restoration practices. However, the effectiveness of restoration projects for providing thermal refuge and creating diverse temperature regimes at the watershed scale remains unclear. In the Klamath River in Northern California, the Karuk Tribe Fisheries Program, the Mid-Klamath Watershed Council, and the U.S. Forest Service constructed a series of off-channel ponds that recreate floodplain habitat and support juvenile coho salmon (Oncorhynchus kisutch) and steelhead (Oncorhynchus mykiss) along the Klamath River and its tributaries. We instrumented these ponds and applied multivariate auto-regressive time series models of fine-scale temperature data from ponds, tributaries, and the mainstem Klamath River to assess how off-channel ponds contributed to thermal regime di..., Data Collection
In July 2020, we deployed 30 temperature sensors (HOBO MX2201, Onset Corporation, Massachusetts) programmed to measure temperature every 15 minutes in ponds and creeks. We placed 1-4 sensors in each pond to capture local-scale temperature variation. Sensors were installed at approximately ⅓ the water depth (at time of placement), except for two sensors in Goodman Pond, one in Upper Lawrence Pond, and one in Lower Lawrence Pond, where sensors were placed on the bottom of the pond. We chose these locations to capture within-pond variation in thermal habitat, to maximize access and safety, and to facilitate future monitoring. We also placed 1 sensor in the creek upstream of the outlet of each pond. We placed sensors between 7 and 13 July 2020 and read them out between 11 and 13 July 2021. We removed incomplete sensor time series (n = 6 pond sensors and n = 3 creek sensors) resulting either from sensor malfunction or sensors that were no longer submerged because of drought-r..., , # Restored off-channel pond habitats create thermal regime diversity and refuges within a Mediterranean-climate watershed

This study used water temperature data to understand how human-made off-channel floodplain ponds in the Klamath River watershed in Northern California contribute to thermal regime diversity and create thermal refuge habitat. We used multivariate auto-regressive time series models and wavelet analysis to assess how ponds created thermal regime diversity in the riverscape over time. Datasets belonging to the Karuk Tribe and the Mid Klamath Watershed Council are only available upon request. Please contact the corresponding author ([[e-mail]](mailto:jessie_moravek@berkeley.e)) for assistance accessing these datasets.

## Pond Temperature Data

Pond and creek temperature data were obtained via a series of temperature sensors (HOBO MX2201) placed in 9 ponds and 2 creeks from July 2020-July 2021. Water temperature was measured every 15 minutes. Sensor...