Mechanisms Driving Decadal Changes in the Carbonate System of a Coastal Plain Estuary

Da, Fei; Friedrichs, Marjorie A. M.; St‐Laurent, Pierre; Shadwick, Elizabeth H.; Najjar, Raymond G.; Hinson, Kyle E.

doi:10.1029/2021jc017239

Cited by 10 publications

(13 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A consideration of this alternative threshold value could help to identify habitat environments for shell-forming species in Chesapeake Bay, and to inform empirical and process-based models of mineral dissolution and precipitation in estuarine environments. Specifically, existing carbonate biogeochemistry models in Chesapeake Bay either do not fully consider calcium carbonate processes , or apply conventional saturation state thresholds initially derived and widely used in coastal and open ocean areas because of a lack of field data to quantify the occurrence and magnitude of calcium precipitation/dissolution in estuarine environments. The threshold estimated from 20 years of bay-wide water quality data in this study could be incorporated into the process-based physical-biogeochemical models, reducing the biases and uncertainties in carbonate chemistry simulations (e.g., CO 2 sink/source, climate change on estuarine pH).…”

Section: Resultsmentioning

confidence: 99%

Decoupling of Estuarine Hypoxia and Acidification as Revealed by Historical Water Quality Data

Shen

Testa

Herrmann

et al. 2022

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Hypoxia and acidification are commonly coupled in eutrophic aquatic environments because aerobic respiration is usually dominant in bottom waters and can lower dissolved oxygen (DO) and pH simultaneously. However, the degree of coupling, which can be weakened by non-aerobic respiration and CaCO3 cycling, has not been adequately assessed. In this study, we applied a box model to 20 years of water quality monitoring data to explore the relationship between hypoxia and acidification along the mainstem of Chesapeake Bay. In the early summer, dissolved inorganic carbon (DIC) production in mid-bay bottom waters was dominated by aerobic respiration, contributing to DO and pH declines. In contrast, late-summer DIC production was higher than that expected from aerobic respiration, suggesting potential buffering processes, such as calcium carbonate dissolution, which would elevate pH in hypoxic waters. These findings are consistent with contrasting seasonal relationships between riverine nitrogen (N) loads and hypoxic and acidified volumes. The N loads were associated with increased hypoxic and acidified volumes in June, but only increased hypoxic volumes in August, when acidified volume declines instead. Our study reveals that the magnitude of this decoupling varies interannually with watershed nutrient inputs, which has implications for the management of co-stressors in estuarine systems.

show abstract

Section: Resultsmentioning

confidence: 99%

Decoupling of Estuarine Hypoxia and Acidification as Revealed by Historical Water Quality Data

Shen

Testa

Herrmann

et al. 2022

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Like many other coastal areas (e.g., Scanes et al, 2020;Da et al, 2021), the nwGOM estuaries have experienced gradual but significant warming over the past decades, with the overall warming rate of 0.0428 • C yr −1 (Montagna et al, 2011b). This change alone would lead to 1-2 µatm yr −1 increase in pCO 2 and ∼0.0004-0.0006 yr −1 decrease in pH, based on the average water chemistry parameters and an average temperature of 25 • C in Supplementary Table 2.…”

Section: Spatial Heterogeneity In Carbonate System Parameters and Lon...mentioning

confidence: 99%

Long-Term Trends in Estuarine Carbonate Chemistry in the Northwestern Gulf of Mexico

McCutcheon

2022

Front. Mar. Sci.

View full text Add to dashboard Cite

A four-decade dataset that spans seven estuaries along a latitudinal gradient in the northwestern Gulf of Mexico and includes measurements of pH and total alkalinity was used to calculate partial pressure of CO2 (pCO2), dissolved inorganic carbon (DIC), saturation state of aragonite (ΩAr), and a buffer factor (βDIC, which measures the response of proton concentration or pH to DIC concentration change) and examine long-term trends and spatial patterns in these parameters. With the notable exception of the northernmost and southernmost estuaries (and selected stations near freshwater input), these estuaries have generally experienced long-term increases in pCO2 and decreases in DIC, ΩAr, and βDIC, with the magnitude of change generally increasing from north to south. At all stations with increasing pCO2, the rate of increase exceeded the rate of increase in atmospheric pCO2, indicating that these estuaries have become a greater source of CO2 to the atmosphere over the last few decades. The decreases in ΩAr have yet to cause ΩAr to near undersaturation, but even the observed decreases may have the potential to decrease calcification rates in important estuarine calcifiers like oysters. The decreases in βDIC directly indicate that these estuaries have experienced continually greater change in pH in the context of ocean acidification.

show abstract

“…Modeling studies and retrospective data analysis have shown significant but complex long-term pH trends in Chesapeake bay over the past three decades (Shen et al, 2020;Da et al, 2021). In the upper bay, where pH in near-surface waters has historically been low, there has been a long-term increase (basification), influenced by freshwater input and increasing alkalinity in the Susquehanna River (Kaushal et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Coupled Carbonate Chemistry - Harmful Algae Bloom Models for Studying Effects of Ocean Acidification on Prorocentrum minimum Blooms in a Eutrophic Estuary

Li¹,

Li²,

Glibert³

2022

Front. Mar. Sci.

View full text Add to dashboard Cite

Eutrophic estuaries have suffered from a proliferation of harmful algal blooms (HABs) and acceleration of ocean acidification (OA) over the past few decades. Despite laboratory experiments indicating pH effects on algal growth, little is understood about how acidification affects HABs in estuaries that typically feature strong horizontal and vertical gradients in pH and other carbonate chemistry parameters. Here, coupled hydrodynamic–carbonate chemistry–HAB models were developed to gain a better understanding of OA effects on a high biomass HAB in a eutrophic estuary and to project how the global anthropogenic CO2 increase might affect these HABs in the future climate. Prorocentrum minimum in Chesapeake bay, USA, one of the most common HAB species in estuarine waters, was used as an example for studying the OA effects on HABs. Laboratory data on P. minimum grown under different pH conditions were applied in the development of an empirical formula relating growth rate to pH. Hindcast simulation using the coupled hydrodynamic-carbonate chemistry–HAB models showed that the P. minimum blooms were enhanced in the upper bay where pH was low. On the other hand, pH effects on P. minimum growth in the mid and lower bay with higher pH were minimal, but model simulations show surface seaward estuarine flow exported the higher biomass in the upper bay downstream. Future model projections with higher atmospheric pCO2 show that the bay-wide averaged P. minimum concentration during the bloom periods increases by 2.9% in 2050 and 6.2% in 2100 as pH decreases and 0.2 or 0.4, respectively. Overall the model results suggest OA will cause a moderate amplification of P. minimum blooms in Chesapeake bay. The coupled modeling framework developed here can be applied to study the effects of OA on other HAB species in estuarine and coastal environments.

show abstract

Mechanisms Driving Decadal Changes in the Carbonate System of a Coastal Plain Estuary

Cited by 10 publications

References 92 publications

Decoupling of Estuarine Hypoxia and Acidification as Revealed by Historical Water Quality Data

Decoupling of Estuarine Hypoxia and Acidification as Revealed by Historical Water Quality Data

Long-Term Trends in Estuarine Carbonate Chemistry in the Northwestern Gulf of Mexico

Coupled Carbonate Chemistry - Harmful Algae Bloom Models for Studying Effects of Ocean Acidification on Prorocentrum minimum Blooms in a Eutrophic Estuary

Contact Info

Product

Resources

About