Data from: Effects of elevated seawater pH and total alkalinity following dosing of sodium hydroxide in Calanus finmarchicus
Data files
Apr 27, 2026 version files 6.52 MB
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Dataset1_CFin_survival_escapeResponse.csv
21.13 KB
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Dataset2_CFin_MO2.csv
6.49 MB
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Dataset3_CFin_MO2_dryMass.csv
2.99 KB
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README.md
3.68 KB
Abstract
This dataset contains measurements of survival, escape performance, and oxygen consumption for the copepod Calanus finmarchicus following short-term exposure to NaOH-dosed seawater intended to simulate transient exposure during ocean alkalinity enhancement (OAE) field deployments. Late-stage copepodites (C4–C5; “juveniles”) and adult females (C6) were exposed to two elevated pH/total alkalinity (TA) conditions: pH 10.5 (~5,000 µmol kg⁻¹ TA) for 1, 5, or 10 minutes and pH 9.0 (~3,150 µmol kg⁻¹ TA) for 1, 15, or 30 minutes, alongside an ambient control: pH 8.0 (2,150 µmol kg⁻¹ TA).
Survival was recorded immediately after exposure and during subsequent monitoring through 72 hours post-exosure (hpe). Escape response (ability to initiate an escape jump) was assessed immediately post-exposure and at follow time points at 24 and 72 hpe. Routine metabolic rate was quantified via microplate respirometry as oxygen consumption following a 10-minute exposure to pH 10.5, measured immediately after exposure for both life stages and again at 12 hpe for juveniles. The dataset provides carbon chemistry measurements, survival and escape response measurements, and oxygen consumption measurements.
Dataset DOI: 10.5061/dryad.s7h44j1p1
Description of the data and file structure
We collected these data to quantify acute biological responses of the copepod Calanus finmarchicus to short, high-intensity pH and total alkalinity (TA) perturbations expected during ocean alkalinity enhancement (OAE) plume exposure. Late-stage copepodites (C4–C5; juveniles) and adult females (C6) were exposed to NaOH-dosed seawater at pH 10.5 (~5,000 µmol kg⁻¹ TA) for 1, 5, or 10 minutes and at pH 9.0 (~3,150 µmol kg⁻¹ TA) for 1, 15, or 30 minutes, with an ambient control (pH 8.0; ~2,150 µmol kg⁻¹ TA). Following exposure, individuals were assessed for immediate mortality and then monitored for survival through 72 hours post-exposure (hpe). Escape performance (ability to initiate an escape response) was measured immediately after exposure and at subsequent time points (including 24 hpe). Routine metabolic rate was quantified as oxygen consumption using microplate respirometry following a 10-minute exposure to pH 10.5, measured immediately post-exposure in both life stages and again at 12 hpe in juveniles.
Files and variables
File: Dataset1_CFin_survival_escapeResponse.csv
Description:
Variables
- trial: unique trial identifier
- life_stage: copepod life stage examined
- trial_date: start date of the trial MM/DD/YYYY
- repID: unique replicate identifier
- pH_level: pH treatment level (total scale)
- exposure_duration: exposure duration (minutes)
- treatment: combined pH level × duration treatment factor (extreme = pH 10.5; moderate = pH 9.0)
- N_copes_starting: number of copepods in each replicate vessel at the start of the trial
- time_check: time post-exposure (hours) when replicates were sampled for survival and escape response
- at_risk: number of live copepods counted at the previous evaluation time point
- surv_count: number of live copepods counted at each evaluation time point
- dead_count: number of dead copepods counted at each evaluation time point
- ER_count: number of copepods showing a successful escape response
- ER_failed_count: number of copepods that failed to show a successful escape response
- surv_ratio: survival ratio at each time point (current number alive ÷ starting number in that vessel)
- ER_ratio: escape response ratio at each time point (number with successful escape response ÷ number alive at that evaluation time point)
File: Dataset2_CFin_MO2.csv
Description:
Variables
- MO2_assay: unique respirometry assay identifier
- life_stage: copepod life stage examined
- microplate_wellID: microplate well identifier
- type: well type (blank or containing a copepod)
- sample_ID: unique sample identifier
- sample_name: full sample name
- time_seconds: time into the measurement (seconds)
- time_mins: time into the measurement (minutes)
- DO_as: dissolved oxygen concentration (percent air saturation)
- DO_umol_L: dissolved oxygen concentration (micromoles per liter)
File: Dataset3_CFin_MO2_dryMass.csv
Description:
Variables
- assay: unique respirometry assay identifier
- life_stage: copepod life stage examined
- wellID: microplate well identifier
- treatment: treatment name
- sample_name: unique sample name
- dry_mass_mg: copepod dry mass (mg)
Code/software
All analyses were conducted in R (v4.0.2) using RStudio (v1.3).