DOI: 10.5061/dryad.brv15dvkp
title: Beyond latitude: Thermal tolerance and vulnerability of a broadly distributed salmonid across a habitat temperature gradient

description: Salmonid fishes are a focal point of conservation physiology due to their
 high value to humans and ecosystems, and their susceptibility to decline
 from climate change. A significant challenge in conserving these fishes is
 that populations of the same species can be locally adapted to vastly
 different habitats within their wild ranges and can therefore have unique
 tolerance or vulnerability to environmental stressors within those
 habitats. Within the state of Oregon, USA, summer steelhead (Oncorhynchus
 mykiss) inhabit both cool, coastal waters most typically associated with
 Pacific salmonids as well as arid, inland environments where temperatures
 are more extreme. Here, we utilized streamside physiological experiments
 paired with habitat temperature monitoring to assess the thermal tolerance
 and vulnerability of four populations of summer steelhead from distinct
 thermal habitats. All populations had unique responses of critical thermal
 maximum, aerobic scope, and exercise recovery to temperature. Despite
 populations from warm habitats exhibiting higher thermal tolerance than
 populations from cooler habitats, summer steelhead from warm habitats
 appear to be more vulnerable to the physiological consequences of warming
 based on the extreme temperatures they already experience during the
 summer. These results demonstrate an example of thermal physiology varying
 between populations within the same portion of their latitudinal range and
 highlight the need for habitat-specific conservation strategies for this
 species.
description: ## Beyond Latitude: Thermal Tolerance and Vulnerability of a Broadly
 Distributed Salmonid Across a Habitat Temperature Gradient This dataset
 includes respirometry data (maximum and resting metabolic rate, aerobic
 scopes, exercise recovery) and critical thermal maximum data on juvenile
 summer steelhead from 4 watersheds in Oregon, USA: John Day, Siletz, Lower
 Deschutes, and North Umpqua.
 [https://doi.org/10.5061/dryad.brv15dvkp](https://doi.org/10.5061/dryad.brv15dvkp) ## **GENERAL INFORMATION** **Title:** Beyond Latitude: Thermal Tolerance and Vulnerability of a Broadly Distributed Salmonid Across a Habitat Temperature Gradient **Authors:** Terra Dressler, Kara Anlauf-Dunn, Andrea Chandler, Erika Eliason **Principal Investigator Email:** [eliason@ucsb.edu](mailto:eliason@ucsb.edu) **Date range of data collection:** 2021-07-12 to 2022-08-12 **Location of data collection:** Oregon, USA ## **FILE OVERVIEW** **File List:** CTmax_SummerSteelhead.csv; Aerobic_Scopes_SummerSteelhead.csv; RMR_SummerSteelhead.csv; Recovery_SummerSteelhead.csv * CTmaxSummerSteelhead.csv includes critical thermal maximum (units: degrees Celsius, column name: ctmax) data for each of 4 summer steelhead populations (column name: population) held at 3-4 different fluctuating temperature treatments (treatment name column: treatment, treatment temperature column: mmr_temp). Also included is the temperature of the fish were at during the start of the trial (column name: trial_start_max, units: degrees Celsius). * AerobicScopeSummerSteelhead.csv includes mass-scaled maximum and resting metabolic rate (MMR & RMR) as well as absolute and factorial aerobic scope (AAS & FAS; column names: aas, fas; units: mgO2/kg/L) for each population (column name: population) and temperature treatment (column name: temp, units: degrees Celsius). Also includes are body weight (column name: bw, units: kg), mass-scaled MMR (column name: mmr_scaled, units: mgO2/kg/L) and RMR (column name: rmr_scaled, units: mgO2/kg/L) that were used to calculate aerobic scopes. * RMRSummerSteelhead.csv includes mass-scaled resting metabolic rate (column name: meanrmr72; units: mgO2/kg/L) data for all populations (column name: population) and treatments (column names: treatment & mmr_temp). Fish were held at fluctuating temperatures and RMR was measured at each acute temperature during the fluctuation (column name: temp; units: degrees Celsius). Also included are body weight (column name: bw, units: kg) and number of individual RMR measurements comprising mean_rmr (column name: n_rmr). * Recovery_SummerSteelhead.csv includes exercise recovery data for each fish. This is metabolic rate data measured for 1 hour after fish were chased to exhaustion (metabolic rate column name: mo2_scaled (units: mgO2/kg/L), time data column name: min_start_real (units: minutes). This file also includes date and time of each metabolic rate measurement (DateTime), body weight (column name: bw, units: kg), and coefficients for biexponential decay models (B, beta, A, alpha) fit to the relationship between metabolic rate and time for each population and temperature treatment. **Data Collection Methods:** see associated manuscript (Dressler et al., 2025 *Conservation Physiology*) Link to data analysis R code: [https://github.com/terradressler/2024_Dressler_et_al_Cons_Phys_OregonSST](https://github.com/terradressler/2024_Dressler_et_al_Cons_Phys_OregonSST)