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Technical Documentation, State of the Ecosystem Report

48 Ocean Acidification

Description: Maps and variability of regional carbonate chemistry and other oceanographic properties

Indicator category: Synthesis of published information or openly accessible datasets

Found in: State of the Ecosystem - Gulf of Maine & Georges Bank (2021+); State of the Ecosystem - Mid-Atlantic Bight (2021+)

Contributor(s): Grace Saba, Lori Garzio

Data steward: Grace Saba , Lori Garzio

Point of contact: Grace Saba , Lori Garzio

Public availability statement: Source data is available to the public (see Data Sources).

48.1 Methods

The New England Fishery Management Council (NEFMC) and Mid-Atlantic Fishery Management Council (MAFMC) have recently requested regional Ocean Acidification (OA) information in the State of the Ecosystem reports. The work included in the State of the Ecosystem 2021 report, seasonal dynamics of pH in shelf waters in the Mid-Atlantic, was synthesized from Wright-Fairbanks et al. (2020). The maps included in the State of the Ecosystem 2022 reports include a plot of bottom pH in summer over the entire U.S. Northeast Shelf (2007-2021), and glider-based pH profiles during summer 2021 in both the Mid-Atlantic Bight (MAB) and the Gulf of Maine. The plots in the State of the Ecosystem 2023 reports included maps of bottom summer aragonite saturation (ΩArag, or omega) over the entire U.S. Northeast Shelf (2007-2022) and locations where summer bottom ΩArag reached lab-derived sensitivity levels of designated target species.

The products developed for the State of the Ecosystem 2024 reports include: plots of the seasonal progression (Spring-Fall 2023) of oceanographic properties (including temperature, chlorophyll, dissolved oxygen, pH, and aragonite saturation state) on the New Jersey coastal shelf; plots summarizing a multi-stressor event in the Mid-Atlantic during summer 2023; static and animated maps of summer-time bottom pH and aragonite saturation state on the U.S. Northeast Shelf (2007-2023); and maps of locations where species sensitivity levels for aragonite saturation state were reached in bottom water during the summer (2007-2023).

Products from all State of the Ecosystem reports to date were developed using openly accessible, quality-controlled data from vessel-based discrete samples and glider-based measurements (see Data Sources), and data from published laboratory-based experimental studies (see Plotting)

48.1.1 Data sources

Glider-based observations of pH (and other variables including temperature, salinity, chlorophyll-a, and dissolved oxygen) began in the southern MAB region in May 2018 (Saba et al. 2019), and seasonal glider pH missions thereafter began in February 2019 (Wright-Fairbanks et al. 2020; although no deployments occurred in 2020 as a result of the COVID pandemic). Simultaneous measurements from the glider’s pH, temperature, and salinity sensors enable the derivation of total alkalinity and calculation of other carbonate system parameters including aragonite saturation state (ΩArag). The glider pH observation program expanded spatially and temporally, with additional deployments in the northern MAB (New York Bight) and the Gulf of Maine, starting in February 2021. A typical glider mission runs for about 4 weeks, covers 500 km, and collects data though the full water column.

For the 2023 glider data cross-section plots (2023 seasonal progression of oceanographic properties on the New Jersey coastal shelf and plots summarizing a multi-stressor event in the Mid-Atlantic during summer 2023): Full-resolution delayed-mode glider datasets from six deployments (Spring-Fall 2023) were downloaded from the RUCOOL Glider ERDDAP server. These datasets were QC’d and pH was calculated from raw variables (where applicable) using python code, and the final processed NetCDF datasets containing all relevant metadata can be found here.

For the summer 2007-2023 bottom-water pH and aragonite saturation state data synthesis (static and animated maps of summer-time bottom pH and aragonite saturation state on the U.S. Northeast Shelf [2007-2023]; maps of summer-time bottom locations where species sensitivity levels for aragonite saturation state were reached [2007-2023]): Full-resolution delayed-mode glider datasets from seven deployments were downloaded from the RUCOOL Glider ERDDAP server and the IOOS Glider DAC ERDDAP server (SBU01 2022-2023 deployments). These datasets were QC’d and pH was calculated from raw variables (where applicable) using python code, and the final processed NetCDF datasets containing all relevant metadata for each glider deployment used in the synthesis can be found here. Resulting data files containing combined summer-time bottom pH and aragonite saturation state data from glider-based (and vessel-based, see below) measurements can be found here. Vessel-based data were mined from the Coastal Ocean Data Analysis Product in North America, version v2021 (Jiang et al. 2021). This data product synthesizes two decades of quality-controlled inorganic carbon system parameters (including pH, total alkalinity, dissolved inorganic carbon) along with other physical and chemical parameters (temperature, salinity, dissolved oxygen, nutrients) collected from the North American continental shelves. Additionally, four recent vessel-based datasets that were not included in CODAP-NA (Jiang et al. 2021) were included in this synthesis. These datasets were collected during more recent NOAA NEFSC Ecosystem Monitoring (EcoMon) surveys: June 2019 (Cruise ID HB1902), August 2019 (Cruise ID GU1902), August 2021 (Cruise ID PC2104), June 2022 (Cruise ID HB2204). These datasets were downloaded via the NCEI Ocean Carbon and Acidification Data Portal. Resulting data files containing combined summer-time bottom pH and aragonite saturation state data from vessel-based (and glider-based, see above) measurements can be found here.

48.1.2 Data extraction

Glider data were processed and quality-controlled by software technician Lori Garzio at Rutgers University.

CODAP-NA, Version 2021 data were accessed and downloaded on October 14, 2021.

EcoMon datasets were accessed and downloaded on October 13, 2022 (Cruise IDs HB1902, GU1902, PC2104) and November 17, 2023 (Cruise ID HB2204).

48.1.3 Data processing

For processing and quality-control procedures of glider-based data, see Wright-Fairbanks et al. (2020). For the 2023 glider data cross-section plots (2023 seasonal progression of oceanographic properties on the New Jersey coastal shelf and plots summarizing a multi-stressor event in the Mid-Atlantic during summer 2023): datasets were QC’d and pH was calculated from raw variables (where applicable) using python code, and the final processed NetCDF datasets containing all relevant metadata can be found here.

Data from CODAP-NA were filtered temporally to include only those collected during summer months (June-August) and were spatially limited to the U.S. Northeast Shelf. The resulting datasets included those from major vessel-based campaigns (East Coast Ocean Acidification, ECOA I and II cruises 2015 and 2018; The Gulf of Mexico and East Coast Carbon cruises, GOMECC 2007 and 2012; EcoMon 2012-2013, 2015-2019).

For vessel-based datasets, when ΩArag was unavailable it was calculated using PyCO2SYS (Humphreys et al. 2020) with inputs of pressure, temperature, salinity, total alkalinity, and pH.

For MAB glider datasets, total alkalinity was calculated from salinity using a linear relationship determined from in situ water sampling data taken during glider deployment and recovery in addition to ship-based water samples (Wright-Fairbanks et al. 2020). For the Gulf of Maine glider dataset, total alkalinity was calculated from temperature and salinity using Table 3 Equation IV in McGarry et al. (2021). Calculations for ΩArag were then conducted using PyCO2SYS (Humphreys et al. 2020) with inputs of pressure, temperature, salinity, total alkalinity, and pH.

Bottom water values were defined as the median of the measurements (or calculated ΩArag values) within the deepest 1m of a glider profile or, for vessel-based measurements, the deepest measurement of a vertical CTD/Rosette cast where water samples were collected, for profiles deeper than 10m. In order to validate whether the deepest depth was at or near the bottom, the sampling depth was compared to water column depth (when provided) or water depths extracted from a GEBCO bathymetry grid based on the sample collection coordinates. Any glider profiles/vessel-based casts with the deepest measurement shallower than the bottom 20% of total water column depth were removed. This allowed for a sliding scale instead of providing a strict cut off (e.g., 1 m above the bottom). Resulting data files containing combined summer-time bottom pH and aragonite saturation state data from glider- and vessel-based measurements can be found here.

48.1.4 Plotting

A set of plots was constructed for the 2024 State of the Ecosystem reports:

  1. Maps of four 2023 glider deployments on the coastal New Jersey shelf and the resulting vertical profiles of oceanographic parameters characterizing the evolution of temperature (in °C), chlorophyll, dissolved oxygen, pH, and aragonite saturation state from Spring through Early Fall. See Figure 1 in the Ocean Acidification and Other Stressors catalog page and available here.
  2. Mission tracks of three gliders deployed off the coast of New Jersey in August and September and locations of hypoxic levels of dissolved oxygen (< 3 mg/liter) and low aragonite saturation state (< 1) measured along the glider mission tracks and locations of reported fish, lobster, and/or crab mortalities. See Figure 2 in the Ocean Acidification and Other Stressors catalog page.
  3. Complete cross-sections of dissolved oxygen concentrations, pH, and aragonite saturation state measured along the associated mission tracks during the deployments of the three gliders during August and September 2023. See Figure 3 in the Ocean Acidification and Other Stressors catalog page.
  4. Animated map of summer-time bottom pH on the U.S. Northeast Shelf (2007-2023): access here. Includes all available data from 2007-2023 and includes both glider-based measurements and vessel-based discrete samples.
  5. Animated map of summer-time bottom aragonite saturation state (omega) on the U.S. Northeast Shelf (2007-2023): access here. Includes all available data from 2007-2023 and includes both glider-based measurements and vessel-based discrete samples.
  6. Individual maps (by year, 2007-2023) used to make the animated map for summer-time bottom pH on the U.S. Northeast Shelf: access here. Includes all available data from 2007-2023 and includes both glider-based measurements and vessel-based discrete samples.
  7. Individual maps (by year, 2007-2023) used to make the animated map for summer-time bottom aragonite saturation state (omega) on the U.S. Northeast Shelf: access here. Includes all available data from 2007-2023 and includes both glider-based measurements and vessel-based discrete samples.
  8. Maps of locations where species sensitivity levels for aragonite saturation state (omega) were reached in bottom water (all summer-time data 2007-2023, or by individual summers between 2007-2023): access here.
  1. Includes all available data from 2007-2023 and includes both glider-based measurements and vessel-based discrete samples.
  2. Sensitivity levels of ΩArag were defined for each species as values of ΩArag where negative responses by an organism were observed during an experimental laboratory study. Typically, these laboratory experiments measure organism responses under ocean acidification conditions (lower pH, lower ΩArag) against a control under ambient conditions (higher pH, higher ΩArag). Most laboratory experiments have used a range of ΩArag between 0.5 to 2.0, which does not encompass the full range of ΩArag observed in situ. The metrics measured (e.g., survival, growth, calcification) can be different between experiments, but negative responses could include decreased survival, reduced growth, reduced calcification rate, reduced hatching success, and malformation. Because laboratory perturbation experiments testing the responses of organisms to ocean acidification conditions are a relatively new approach and logistically quite challenging, there are currently few published studies for individual species. Recent studies have also started incorporating additional stressors, which makes defining an OA-focused sensitivity level difficult. Therefore, with additional future studies, the ΩArag sensitivity levels defined here for these species are subject to change.
  3. For the Mid-Atlantic region, designated target species included Atlantic sea scallop (Placopecten magellanicus) and Longfin squid (Doryteuthis pealeii). The sensitivity value used for Atlantic sea scallop was ΩArag ≤ 1.1 at 9 °C, based on reduced adult calcification rate observed at this level in Cameron et al. (2022). The sensitivity value used for longfin squid was ΩArag ≤ 0.96, based on embryo and paralarvae malformation, increased time to hatching and decreased hatching success, and changes to mantle length and statolith morphology observed at this level in Zafroff et al. (2019) and Zafroff & Mooney (2020). Habitat depth ranges used for plotting the observed ΩArag values ≤ sensitivity ΩArag values for Atlantic sea scallop and longfin squid were limited to 25-200 meters (NEFSC 2014) and 0-400 meters (Jacobson et al. 2005), respectively. Bottom water data collected during 2023 were incorporated to update this product for the Mid-Atlantic species, Atlantic sea scallop and longfin squid (available here).
  4. For the New England region, designated target species included Atlantic cod (Gadus morhua) and American lobster (Homarus americanus). The sensitivity value used for Atlantic cod was ΩArag ≤ 1.31 at 10 °C, based on decreased larval survival observed at this level in Stiasny et al. (2016). The sensitivity value used for American lobster was ΩArag ≤ 1.09, based on decreased stage V and VI juvenile survival observed at this level in Noisette et al. (2021). Habitat depth ranges used for plotting the observed ΩArag values ≤ sensitivity ΩArag values for Atlantic cod and American lobster were limited to 10-200 meters (Gregory et al. 2004; DeCelles et al. 2017) and 10-700 meters (Mercaldo-Allen et al. 1994), respectively. Because there were no additional 2023 bottom water aragonite saturation state data available in the Gulf of Maine to update this same product from the previous year’s report, maps for Atlantic cod and American lobster are not included in this year’s catalog page. However, the maps for the individual years between 2007-2022 and the combined map for this same time period are available for these species here.

Data processing code can be found on Github here, and all data files use in these analyses and syntheses can be found here.

catalog link https://noaa-edab.github.io/catalog/ocean_acidification.html