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https://console.cloud.google.com/storage/browser/nmfs_odp_afsc/RACE/SAP/Long%3B%20Effects%20of%20ocean%20acidification%20on%20respiration,%20feeding,%20and%20growth%20of%20juvenile%20red%20and%20blue%20king%20crabs%20%28Paralithodes%20camtschaticus%20and%20P.%20platypus%29; |
https://console.cloud.google.com/storage/browser/nmfs_odp_afsc/RACE/SAP/Long%3B%20Effects%20of%20ocean%20acidification%20on%20respiration,%20feeding,%20and%20growth%20of%20juvenile%20red%20and%20blue%20king%20crabs%20%28Paralithodes%20camtschaticus%20and%20P.%20platypus%29; |
Note: Dataset migrated by Dan Woodrich (AFSC data management coordinator) on 12/16/2021.
Contact: Daniel.woodrich@noaa.gov |
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https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords |
GCMD Keyword Forum Page |
Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 22. Greenbelt,
MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard
Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA).
URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords |
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https://www.afsc.noaa.gov |
Website |
Website for this organization |
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https://www.fisheries.noaa.gov/inport/item/36615 |
Full Metadata Record |
View the complete metadata record on InPort for more information about this dataset. |
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https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/afsc/dmp/pdf/36615.pdf |
NOAA Data Management Plan (DMP) |
NOAA Data Management Plan for this record on InPort. |
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During the experiment, crabs were held in individual cells made out of PVC pipe with
mesh bottoms that were placed in three larger experimental tubs. Cells each received
flow-through water and were large enough to not cause stress to the animals. Crab
were fed Gelly Belly (above) three times a week to excess during the experiment.
The temperature was maintained at 5°C, which is well within the thermal tolerance
range for both species (Long and Daly in review), in each tub using a recirculating
chiller. Each of the tubs was fed with flow through seawater at one of three pHs.
To acidify seawater, CO2 was bubbled into seawater to reduce the pH to 5.5. This
water was mixed with ambient filtered seawater into treatment head tanks. The flow
rate of pH 5.5 water was controlled via feedback from pH probes in the head tanks
that adjusted the speed of peristaltic pumps.
Three pH treatments were used, ambient (pH ~8.1), pH 7.8 (pH expected in global surface
waters in ~2100) and pH 7.5 (~2200). The pH and temperature were measured in a randomly
selected cell in each treatment once a day using a Durafet III pH probe that was calibrated
daily in TRIS buffer. Weekly water samples from each treatment were taken, poisoned
with mercuric chloride, and sent to an analytic laboratories for dissolved inorganic
carbon (DIC) and total alkalinity (TA) analysis.
DIC and TA were determined using a VINDTA 3C (Marianda, Kiel, Germany) coupled to
a 5012 Coulometer (UIC Inc., Joliet, IL) using Certified Reference Material from the
Dickson Laboratory.
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In this experiment, we measured respiration and feeding ration crabs both immediately
after exposure to treatment water and after 3 weeks acclimation period in treatment
water. Three weeks exposure time was selected, in part, because, after that, the mortality
rate of juveniles in the lowest pH treatment was likely to result in too low a sample
size.
Sample size was 6 crabs per species per treatment except for red king crab at pH 7.5
which we increased to 10 crabs in anticipation of a higher mortality rate
at that treatment. As no more than five respirometry measurements could be made per
day, trials for individual crabs were staggered and crabs were started in a random
order.
Part way through beginning the experiment, an equipment failure caused mass mortality
in the pH 7.5 treatment. The affected crabs were replaced with new one and the initial
respiration/feeding trials re-run. Each crab was starved for 1 day prior to measuring
the respiration and feeding ration to standardize hunger levels.
Each day the respiration trials for that day would be performed and the crabs placed
into their cells in the experimental tubs. Respiration was measured in a 5 ml Plexiglas
cell with an integrated Clark electrode oxygen sensor that recorded the O2 concentration
continually. The sensor was calibrated daily with a two point calibration procedure.
The cell was jacketed in by a secondary chamber that allowed flow-through water to
maintain the cell at a constant temperature and the whole apparatus was placed inside
a temperature controlled room at 5°C.
To measure respiration rates, crabs were placed into the cell with a known volume
of water at the treatment pH. Trials were run for 1.25-1.5 h. Immediately after
the trial the crab was removed from the chamber it was blotted dry and the wet mass
was determined. The rate of oxygen consumption in the cell was determined by determining
the slope of the oxygen concentration over time once the trend became linear and was
normalizing to the mass of each crab.
After the respiration trials, the crab were placed in their holding cells in the experimental
tubs. Feeding ration was determined the same day as respiration measurements were
taken. A pre-massed piece of squid mantle (blotted dry) ~50% of the mass of the crabs
was placed into each cell and the crab was allowed to feed for 24 h after which the
remaining food was collected, blotted dry, and massed. As the red king crab were
smaller than the blue king crab the mass of food given to each species differed accordingly.
Control trials without crabs were performed in each pH treatment for each species
(to account for any potential difference in the initial mass of the samples) with
3 replicates of each pH/species combination. On average, the mass of squid increased
by 0.8 ± 7.8% (SE) and did not differ among either pH treatments (2-way ANOVA, F2,13
= 0.184, p = 0.834) or species (2-way ANOVA, F1,13 = 1.318, p = 0.272) so the overall
mean was used when calculating the feeding ration. The mass of food consumed was determined
and the feeding ration calculated as the percent of the crab?s mass consumed corrected
for mass change in control trials.
The crabs were held in their treatment water for ~21 days (range 20-24 d) and checked
daily for moults or mortalities. Then the respiration and feeding ration for each
crab was determined a second time in the same way as above.
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The pH treatment the crab was in or the observation was made in. Control = pH of ambient
water coming into the Kodiak Lab; pH 7.8- water adjusted to a pH 0f 7.8 with CO2.
pH 7.5- water adjusted to a pH of 7.5 pH was taken using Durafet pH probe, accuracy
between 0.01 and 0.03.
Salinity values represented in practical salinity units. Blank cells indicate no data
was taken or missing data. Alkalinity values represented in micromoles per kilogram.
Blank cells indicate no data was taken or missing data.
DIC (dissolved inorganic carbon) is also known as the total CO2 and is represented
in micromoles per kilogram. Blank cells indicate no data was taken or missing data.
Species: BKC = blue king crab; RKC = red king crab. Time Indicates whether the measurement
was made at the beginning (Initial) or end (Final) of the experiment. Initial = measurement
made immediately after crab was exposed to treatment water. Final = measurement made
after crab was exposed to treatment water for approximately 3 weeks.
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