DOI: 10.25338/b8qs66
title: Interpopulation variation in growth, CTMax and metabolism among seasonal phenologies of Chinook Salmon

description: Conservation of species facing environmental change requires an
 understanding of interpopulation physiological variation. However,
 physiological data is often scarce and therefore pooled across populations
 and species, erasing potentially important variability between
 populations. Interpopulation variation in thermal physiology has been
 observed within the Salmonidae family, although it has not been associated
 with seasonally distinct migratory phenotypes (i.e., seasonal runs). To
 resolve whether thermal physiology is associated with life-history
 strategy we acclimated four Sacramento River juvenile Chinook salmon
 populations (Coleman fall-run, Feather River fall- and spring-run and
 Sacramento River Winter-run) exhibiting different seasonal migratory
 phenotypes (fall-, spring- and winter-run), at 11, 16 and 20°C and
 assessed variation in growth rate, critical thermal maxima and
 temperature-dependent metabolic traits. We identified population
 differences in the physiological parameters measured and found compelling
 evidence that the critically endangered and endemic Sacramento River
 winter-run Chinook population exhibits thermal physiology associated with
 its early-migration life-history strategy. Acclimation to warm
 temperatures limited the growth and metabolic capacity of winter-run
 Chinook salmon, highlighting the risk of future environmental warming to
 this endemic population.
description: There are two sets of metabolic data contained herein. The first
 (2022_CJFAS_Dryad_Metabolic_Dataset.csv) and the second
 (NOAA_Preliminary_Data-Winter-Run_Small.csv) were captured using different
 equipment due to their size. Metabolic data from the first dataset were
 gathered in the following way, methods for collection of the second
 dataset are appended to the bottom of this section. 
 Fish underwent metabolic trials in one of four, 5 L automated
 swim tunnel respirometers (Loligo, Denmark). The four tunnels were split
 into two paired systems with two tunnels sharing a single sump and heat
 pump. Water for each swim tunnel system was pumped (PM700, Danner USA)
 from the sump into an aerated water bath surrounding each swim tunnel, and
 then returned to the sump. Sumps were supplied with non-chlorinated fresh
 water from a designated well and aerated with air stones. The temperature
 of the sump (and therefore the swim tunnels) was maintained (±0.5°C) by
 circulating water through a heat pump (model DSHP-7; Aqua Logic Delta
 Star, USA) using a high-volume water pump (Sweetwater SHE 1.7 Aquatic
 Ecosystems, USA). In addition, each sump contained a thermostatically
 controlled titanium heater (TH-800; Finnex, USA). Swim tunnels and
 associated sump systems were cleaned and sanitized with bleach weekly to
 reduce potential for bacterial growth. Dissolved oxygen
 saturation within the swim tunnels was measured using fibre-optic dipping
 probes (Loligo OX11250) which continuously recorded data via AutoResp™
 software (version 2.3.0). Oxygen probes were calibrated weekly using a
 two-point, temperature-paired calibration method. Water velocity of the
 swim tunnels was quantified and calibrated using a flowmeter (Hontzcsh,
 Germany) and regulated using a variable frequency drive controller (models
 4x and 12K; SEW Eurodrive, USA). The velocity (precision &lt;1 cm s-1)
 for each tunnel was controlled remotely using the Autoresp™ program and a
 DAQ-M data acquisition device (Loligo, Denmark). Swim tunnels were
 surrounded by shade cloth to reduce disturbance of the fish. Fish were
 remotely and individually monitored using infrared cameras (QSC1352W;
 Q-see, China) connected to a computer monitor and DVR recorder.
 Oxygen consumption rates for both routine and maximum metabolic
 rates were captured using intermittent respirometry(Brett 1964). Flush
 pumps (Eheim 1048A, Germany) for each tunnel pumped aerated fresh water
 through the swim chamber and was automatically controlled via the
 AutoResp™ software and DAQ-M system. This system would seal the tunnel and
 enable the measurement of oxygen consumption attributable to the fish.
 Oxygen saturation levels were not allowed to drop below 80% and restored
 within three minutes once the flush pump was activated. Oxygen saturation
 data from AutoResp™ was transformed to oxygen concentration using the
 following equation: Where %O2Sat is the oxygen
 saturation percentage reported from AutoResp™; αO2 is the coefficient
 temperature-corrected oxygen solubility (mgO2 L-1 mmHg-1); and BP is the
 barometric pressure (mmHg). Oxygen concentration (milligrams of oxygen per
 liter) was measured every second and regressed over time, the coefficient
 of this relationship (milligrams of oxygen per liter per second) was then
 converted to metabolic rate (milligrams of oxygen per kilogram per minute,
 Equation 3). Where R is the calculated coefficient of
 oxygen over time; V is the volume of the closed respirometer; M is the
 mass of the fish in kilograms and ’60’ transforms the rate from per second
 to per minute. An allometric scaling exponent was not incorporated due to
 similarity in fish sizes and to maximize comparability with metabolic data
 from the Mokelumne Hatchery (CA) fall-run population (Poletto et al.
 2017). Routine Metabolic Rate Prior
 to routine metabolic rate (RMR) trials fish were fasted to ensure a
 post-prandial state. Fish reared at 16 or 20°C were fasted for 24 hours,
 while fish acclimated to 11°C were fasted for 48 hours. Fish were then
 transferred into a swim tunnel respirometer between 13:00 and 17:00. After
 a 30-minutes at their acclimation temperature the temperature was adjusted
 at 2°C h-1 to the test temperature (8 – 26°C). Automated intermittent flow
 respirometry began 30 minutes after the test temperature was achieved and
 continued overnight. Measurement periods ranged from 900 to 1800 seconds
 in duration, flush periods were 180-300 seconds. Periods varied in length
 in response to fish size and test temperature to ensure oxygen saturation
 was kept high (&gt;80%) during the trial. A small circulation pump
 (DC30A-1230, Shenzhen Zhongke, China) ensured that water was mixed without
 disturbing the fish. Fish activity was monitored by overhead infra-red
 cameras and measurement periods when the fish were active were discarded.
 RMR was calculated by averaging the three lowest RMR values(Poletto et al.
 2017). RMR measurements were concluded by 08:00 ± 40 min.
 Maximum Metabolic Rate A modified critical
 swimming velocity protocol was used to elicit maximal metabolic rate
 (MMR)(Poletto et al. 2017). Tunnel speed was increased gradually from 0 to
 30 cm s-1 over an ~2 min period and held there for 20 min. For each
 subsequent 20-min measurement period, tunnel velocity was increased 10% up
 to a maximum of 6 cm s-1 per step. Fish were swum until exhausted and
 unable to swim. Swimming metabolism was measured by sealing the tunnel for
 approximately 16 minutes of the 20-minute measurement period. When a fish
 became impinged upon the back screen (&gt;2/3 of body in contact with
 screen) the tunnel velocity was stopped for ~1 minute and then gradually
 returned to the original speed over 2 minutes. A fish was determined to be
 exhausted if it became impinged twice within the same velocity step. At
 this point the tunnel impellor was stopped to allow for recovery. The
 highest metabolic rate measured over a minimum of 5 minutes during active
 swimming was taken as the MMR. Post-experiment, the
 tunnel was returned to the acclimation temperature and fish were
 transferred to a recovery tank and monitored. In seeking evidence of
 metabolic collapse at near-critical temperatures, some metabolic trials
 were conducted at temperatures exceeding the tolerance of the fish. These
 mortality events represent potential lethal upper limits for sub-acute
 thermal persistence (Fig. S1). Data from fish which did not survive the
 trial or recovery were not used in analysis. After a 24-hour recovery
 period fish were euthanized in a buffered solution of MS-222 (0.5g/L).
 Measurements for mass (g), fork length (cm) and total length (cm) were
 taken, and Fulton’s condition factor was calculated.
 Aerobic scope (AS) was calculated as the difference between a
 fish’s RMR and MMR. Thermal optimums (TOPT) were defined as the
 temperature when aerobic scope was maximized, and calculated as the
 root-value of the derivative of the quadratic function describing the
 relationship between AS and test temperature.  Growth
 Data Growth measurements were initiated in mid to late
 spring when all populations would still be rearing prior to outmigration.
 Growth data were gathered every two weeks by measuring a sample of 30 fish
 from each treatment (n=15 per tank, n = 1528 total measurements). Fish
 were not individually marked and therefore growth rate was calculated
 across individuals. Fish were arbitrarily netted from their treatment tank
 and transferred to an aerated five-gallon bucket until measured. Fish were
 air exposed for ~15-20 seconds to measure mass (± 0.01 grams, Ohaus
 B3000D) and fork length (± 0.1 cm) and then placed into a second bucket
 for recovery before returning to their original treatment tank. Fish were
 netted and measured by the same experimenter across all sampling
 days. Condition factor was calculated as Fulton's
 condition factor (K) using the equation K = 100*Mass/Fork
 Length^3. Critical Thermal Maxima
 Critical Thermal Maximum (CTMax) values were quantified according
 to established methods, briefly described below1. We placed six 4L Pyrex
 beakers in a fiberglass bath tray (1m x 2m x .2m). Beakers were aerated
 with an air stone to ensure both adequate oxygen saturation and
 circulation of water within the beaker. The volume of water in each
 individual beaker (approx. 2.5 L) was calibrated to ensure even heating
 across all CTMax beakers (0.33°C/min). Two pumps (PM700, Danner USA) were
 used to circulate water: one pump recirculated water across three heaters
 (Process Technology S4229/P11), while the other distributed heated water
 through the CTMax bath via a distribution manifold. Experiments began with
 water temperature set at the fish’s acclimation temperatures (11, 16 or
 20°C). Fish of appropriate size (n = 377, 12.4 ± 0.83
 cm) were arbitrarily selected from treatment tanks and transferred to
 separate tanks for fasting. To ensure fish were in a similar postprandial
 state, fish reared at 20°C and 16°C were fasted for 24 hours and 11°C fish
 were fasted for 48 hours to account for their slower metabolic rate. Once
 fasted, fish were individually netted and transferred into individual
 beakers within the CTMax heat bath. Fish were given 30 minutes to
 acclimate to their CTMax beaker after which the CTMax trial
 began. During the CTMax trial, beaker temperature was
 taken every 5 minutes using a thermocouple (Omega HH81A). Thermocouple
 measurements were calibrated to a Fisherbrand® NIST certified mercury
 thermometer following each trial. Fish were observed continually for signs
 of distress and loss of equilibrium. The CTMax trial endpoint was loss of
 equilibrium, at which point the temperature of the CTMax beaker was
 recorded2,3. Fish were then removed and retuned to a recovery bath at
 their acclimation temperature. Fish that did not fully recover within
 24-hours were not included in analysis (6% of individuals). After the
 24-hr recovery, fish were weighed (wet mass ± 0.01g) and measured (fork
 length ± 0.1 cm). N ≥ 20 for all treatments (population
 x. acclimation temperature) except for winter-run fish reared at 16 (n=
 17) or 20°C (n=9). Winter-run reared at 20°C were limited due to a
 mortality event.  On October 17th 2018, an outbreak of Columnaris in a
 single tank of winter-run Chinook salmon rearing at 20°C resulted in the
 mortality of the remaining tank population (n=7). Necropsy of the salmon
 indicated empty stomachs. The mortality of this population is hypothesized
 to be a result of thermal stressed after being reared at 20°C for so long
 (202 days). CTM data for the 20°C acclimation group was limited to 9 fish
 tested 41 days prior to the mortality event. Metabolic
 Data for Small Winter-Run Chinook Salmon
 (NOAA_Preliminary_Data_Winter-Run_Small.csv) Fish
 underwent metabolic trials in one of two, 1.5 L automated swim tunnel
 respirometers (Loligo, Denmark). Each tunnel had its own sump and heat
 pump. Water for each swim tunnel system was pumped from the sump into an
 aerated water bath surrounding each swim tunnel, and then returned to the
 sump. Sumps were supplied with non-chlorinated fresh water from a
 designated well and aerated with air stones. The temperature of the sump
 (and therefore the swim tunnels) was maintained (±0.5°C) by circulating
 water through a heat pump using a water pump. In addition, each sump
 contained a thermostatically controlled titanium heater (TH-500; Finnex,
 USA). Swim tunnels and associated sump systems were cleaned and sanitized
 with bleach weekly to reduce the potential for bacterial growth.
 Dissolved oxygen saturation within the swim tunnels was measured
 using fibre-optic dipping probes (Loligo OX11250) which continuously
 recorded data via AutoResp™ software (version 2.3.0). Oxygen probes were
 calibrated weekly using a two-point, temperature-paired calibration
 method. Water velocity of the swim tunnels was quantified and calibrated
 using a flow tracking system (DPTV, Loligo, DE) and regulated using a
 variable frequency drive controller. The velocity (precision &lt;1 cm
 s-1) for each tunnel was controlled manually using precision knobs on the
 drive controller. Swim tunnels were surrounded by shade cloth to reduce
 disturbance of the fish. Fish were remotely and individually monitored
 using infrared cameras connected to a computer monitor and DVR
 recorder. Oxygen consumption rates for both routine and
 maximum metabolic rates were captured using intermittent
 respirometry(Brett 1964) in the same manner as the larger tunnels
 described above. Routine Metabolic Rate
 Prior to routine metabolic rate (RMR) trials fish were fasted for
 48-hours to ensure a post-prandial state. Fish were then transferred into
 a swim tunnel respirometer between 13:00 and 17:00. After a 30-minutes at
 their acclimation temperature the temperature was adjusted at 2°C h-1 to
 the test temperature (8 – 26°C). Automated intermittent flow respirometry
 began 30 minutes after the test temperature was achieved and continued
 overnight. Measurement periods ranged from 900 to 1800 seconds in
 duration, flush periods were 180-300 seconds. Periods varied in length in
 response to fish size and test temperature to ensure oxygen saturation was
 kept high (&gt;80%) during the trial. A small circulation pump
 (DC30A-1230, Shenzhen Zhongke, China) ensured that water was mixed without
 disturbing the fish. Fish activity was monitored by overhead infra-red
 cameras and measurement periods when the fish were active were discarded.
 RMR was calculated by averaging the three lowest RMR values(Poletto et al.
 2017). RMR measurements were concluded by 08:00 ± 40 min.
 Maximum Metabolic Rate A modified critical
 swimming velocity protocol as described above was used to elicit maximal
 metabolic rate (MMR)(Poletto et al. 2017). Tunnel speed was increased
 gradually from 0 to 20 cm s-1 over an ~2 min period and held there for 20
 min. For each subsequent 20-min measurement period, tunnel velocity was
 increased 10% up to a maximum of 3 cm s-1 per step. Fish were swum until
 exhausted and unable to swim. Swimming metabolism was measured by sealing
 the tunnel for approximately 16 minutes of the 20-minute measurement
 period. When a fish became impinged upon the back screen (&gt;2/3 of
 body in contact with screen) the tunnel velocity was stopped for ~1 minute
 and then gradually returned to the original speed over 2 minutes. A fish
 was determined to be exhausted if it became impinged twice within the same
 velocity step. At this point the tunnel impellor was stopped to allow for
 recovery. The highest metabolic rate measured over a minimum of 5 minutes
 during active swimming was taken as the MMR.
 Post-experiment, the tunnel was returned to the acclimation
 temperature and fish were transferred to a recovery tank and monitored. In
 seeking evidence of metabolic collapse at near-critical temperatures, some
 metabolic trials were conducted at temperatures exceeding the tolerance of
 the fish. Data from fish that did not survive the trial or recovery were
 not used in analysis. After a 24-hour recovery period fish were euthanized
 in a buffered solution of MS-222 (0.5g/L). Measurements for mass (g), fork
 length (cm) and total length (cm) were taken. Aerobic
 scope (AS) was calculated as the difference between a fish’s RMR and MMR.
 Thermal optimums (TOPT) were defined as the temperature when aerobic scope
 was maximized, and calculated as the root-value of the derivative of the
 quadratic function describing the relationship between AS and test
 temperature.  Missing values: Only
 fish that successfully completed the Critical Thermal Maximum (CTMax)
 trials are included in this dataset. Fish that did not recover from the
 trial were excluded from analysis, and therefore this dataset. The CTMax
 trial is designed to be survived and therefore failure to recover fully is
 reflective of an abnormality in the fish’s physiology or experimenter
 error, both of which could bias the ultimate results.
 1. Becker, C. D. & Genoway, R. G. Evaluation of the
 critical thermal maximum for determining thermal tolerance of freshwater
 fish. Environmental Biology of Fishes 4, 245–256 (1979).
 2. Beitinger, T. L., Bennett, W. A. & McCauley, R. W.
 Temperature tolerances of North American freshwater fishes exposed to
 dynamic changes in temperature. Environmental Biology of Fishes 58,
 237–275 (2000). 3. Fangue, N. A., Hofmeister, M.
 & Schulte, P. M. Intraspecific variation in thermal tolerance and
 heat shock protein gene expression in common killifish, Fundulus
 heteroclitus. Journal of Experimental Biology 209, 2859–2872
 (2006). 4. Poletto, Jamilynn B., Dennis E. Cocherell,
 Sarah E. Baird, Trinh X. Nguyen, Valentina Cabrera-Stagno, Anthony P.
 Farrell, and Nann A. Fangue. “Unusual Aerobic Performance at High
 Temperatures in Juvenile Chinook Salmon, <em>Oncorhynchus
 Tshawytscha</em>.” <em>Conservation Physiology</em> 5,
 no. 1 (2017): 1–13.
description: # Interpopulation Variation in growth, CTMax and Metabolism among seasonal
 phenologies of Chinook Salmon --- There are 4 datasets. One that pertains
 to growth measurements, one that pertains to CTMax data and the third
 contains data regarding metabolic performance. These first three were used
 in the 2022 CJFAS paper. The fourth dataset contains metabolic data for
 small Winter-run Chinook Salmon (2-3g), these data were gathered on the
 same cohort of fish as those used in the other datasets. These fish were
 only acclimated to 11C, whereas fish in the other datasets were acclimated
 to 11, 16, or 20C. The columns and descriptions for these three datasets
 are below. Only fish used in the analysis for the CJFAS manuscript are
 included in this data. This excludes fish that did not recover from the
 metabolic or CTMax trials or fish from other populations that were
 measured during the same experimental seasons, which leads to gaps in the
 individual numbering of trial fish ## Column Specs:
 CJFAS\_2022\_Dryad\_CTM\_Data.csv SEQ: Numerical number, runs from 1 to
 the end of the dataset, each row gets its own value FISH_NUM: Unique fish
 identification number, gaps in sequence are due to fish which did not
 survive recovery, or data from other populations not included in the
 publication associated with this dataset. HATCHERY: Hatchery
 identification for each fish, Coleman: Coleman National Fish Hatchery,
 Winter-Run: Sacramento River Winter-run from Livingston Stone National
 Fish hatchery, Feather Fall: Feather Fall-run population from the feather
 river hatchery, Feather Spring: Spring-run population from the Feather
 River hatchery ACCLIMATION_TEMPERATURE: Temperature at which each fish was
 acclimated, 11 16 or 20 TANK_ID Rearing tank identity for each fish. As
 tanks were reused between years the tank ID code is formatted as
 TANK_POPULATON_YEAR: Population codes are CO: Coleman, WR: Winter-run, FF:
 Feather Fall and FS: Feather Spring MASS: Fish mass measured in grams
 STANDARD_LENGTH: Standard length from snout to start of caudal fin,
 measured in mm. Fish from the Coleman population were not measured for
 Standard Length and therefore are NA. FORK_LENGTH: Fork length from snout
 to fork in caudal fin, measured in mm TOTAL_LENGTH: Total length from
 snout to furthest extremity of caudal fin, measured in mm
 CONDITION_FACTOR: Fulton's condition factor calculated using the
 equation K = mass*100/(FL^3) CTM_CHAMBER: Specific CTM chamber that a fish
 was trialed in, each CTM chamber was assigned a letter identifier,
 A,B,C,D,E,F or G CTM_DATE: mm/dd/yy of the CTMax Trial AGE_AT_CTMAX: Age
 of the fish at the CTMax trial (Days) ## Column Specs:
 CJFAS\_2022\_Dryad\_Growth\_Data.csv SEQ: Numerical number, runs from 1 to
 the end fo the dataset, each row gets its own value HATCHERY: Hatchery
 identification for each fish, Coleman: Coleman National Fish Hatchery,
 Winter-Run: Sacramento River Winter-run from Livingston Stone National
 Fish hatchery, Feather Fall: Feather Fall-run population from the feather
 river hatchery, Feather Spring: SPring-run population from the Feather
 River hatchery ACCLIMATION_TEMPERATURE: Temperature at which each fish was
 acclimated, 11 16 or 20 TANK_ID: Tank ID as a concatenation of the
 specific tank code (e.g., I4, E3, H1) and the hatchery a fish came from
 DATE: Date that a specific fish was measured (mm/dd/yyyy) DAYS: Days into
 the growth measurement window, starts at 0 YEAR: Year of the growth
 measurements (2017, 2018 or 2019) MASS: Fish mass measured in grams
 STANDARD_LENGTH: Standard length from snout to start of caudal fin,
 measured in mm. Fish from the Coleman population were not measured for
 Standard Length and therefore are NA. FORK_LENGTH: Fork length from snout
 to fork in caudal fin, measured in mm TOTAL_LENGTH: Total length from
 snout to furthest extremity of caudal fin, measured in mm
 CONDITION_FACTOR: Fulton's condition factor calculated using the
 equation K = mass*100/(FL^3) ## Column Specs:
 CJFAS\_2022\_Dryad\_Metabolic\_Dataset.csv SEQ: Numerical number, runs
 from 1 to the end fo the dataset, each row gets its own value FISH_ID:
 Unique fish identification number, gaps in sequence are due to fish which
 did not survive recovery, or data from other populations not included in
 the publication associated withthis dataset. AS_EXP: Four aerobic scope
 trials could be conducted at once, one in each swim tunnel. This value
 keeps track of which trials were conducted concurrently. HATCHERY:Hatchery
 identification for each fish, Coleman: Coleman National Fish Hatchery,
 Winter-Run: Sacramento River Winter-run from Livingston Stone National
 Fish hatchery, Feather Fall: Feather Fall-run population from the feather
 river hatchery, Feather Spring: SPring-run population from the Feather
 River hatchery ACCLIMATION_TEMPERATURE:Temperature at which each fish was
 acclimated, 11 16 or 20 C TEST_TEMPERATURE: Temperature at which metabolic
 trials were conducted at. (8, 10, 12, 14, 16, 18, 20, 22, 23, 24,25 26C)
 TANK_ID:Rearing tank identity for each fish. As tanks were reused between
 years the tank ID code is formatted as TANK_POPULATON_YEAR. Population
 codes are CO: Coleman, WR: Winter-run, FF: Feather Fall and FS: Feather
 Spring TUNNEL_ID: Which of four swim tunnels a fish was trialed in. Trials
 which share a cardinal direction (East vs. West) were connected via a
 shared sump system and therefore test temperatures of fish trialed in
 shared systems were the same. RMR: Routine Metabolic Rate (mgO2/kg/hr)
 MMR: Maximum Metabolic Rate (mgO2/kg/hr) AS: Aerobic Scope (MMR - RMR;
 mgO2/kg/hr) MASS: Fish mass measured in grams STANDARD_LENGTH: Standard
 length from snout to start of caudal fin, measured in mm. Fish from the
 Coleman population were not measured for Standard Length and therefore are
 NA. FORK_LENGTH: Fork length from snout to fork in caudal fin, measured in
 mm TOTAL_LENGTH: Total length from snout to furthest extremity of caudal
 fin, measured in mm CONDITION_FACTOR: Fulton's condition factor (K)
 calculated using the equation K = mass*100/(FL^3) AGE_AT_TRIAL: Age of the
 fish at the CTMax trial (Days) ## Column Specs:
 NOAA\_Preliminary\_Data\_Winter-Run\_Small.csv FISH_ID: Unique fish
 identification number, gaps in sequence are due to fish which did not
 survive recovery, or data from other populations not included in the
 publication associated withthis dataset.\ HATCHERY: Hatchery
 identification for each fish, there is only one value, Winter-run.\
 ACCLIMATION_TEMPERATURE:Temperature at which each fish was acclimated, 11
 16 or 20 C\ TEST_TEMPERATURE: Temperature at which metabolic trials were
 conducted at. (8, 10, 12, 14, 16, 18, 20, 22, 23, 24,25 26C) MASS: Fish
 mass measured in grams\ STANDARD_LENGTH: Standard length from snout to
 start of caudal fin, measured in mm. Fish from the Coleman population were
 not measured for Standard Length and therefore are NA.\ FORK_LENGTH: Fork
 length from snout to fork in caudal fin, measured in mm\ TOTAL_LENGTH:
 Total length from snout to furthest extremity of caudal fin, measured in
 mm\ AS_NUM: Four aerobic scope trials could be conducted at once, one in
 each swim tunnel. This value keeps track of which trials were conducted
 concurrently. RMR_DATE: Date of the RMR trial (m/d/y)\ TUNNEL_ID: Which of
 two 5l Loligo swim tunnels a fish was trialed in.\ RMR: Routine Metabolic
 Rate (mgO2/kg/hr)\ MMR: Maximum Metabolic Rate (mgO2/kg/hr)\ AS: Aerobic
 Scope (MMR - RMR; mgO2/kg/hr) EXP_YEAR: Calendar year when the trial was
 conducted (only value is 2018) LOCATION: Location of source population
 (only value is CA)\ LAT: Latitude of source population (only value is
 40.7162) LONG: Longitude of source population (only value is -122.425
 ELEVATION: Elevation of source population (only value is 179, meters)
 MIGRATION: Distance of source population from San Fancisco Delta (only
 value is 307.4, miles)\ AGE_AT_TEST: Age of the fish at the Metabolic
 trial (Days) ## Sharing/access Information Contact Ken Zillig
 for questions about this data.