Ecosystem metabolism drives pH variability and modulates long-term ocean acidification in the Northeast Pacific coastal ocean

AbstractThis study examines long-term ocean pH data to evaluate ocean acidification (OA) trends at two coastal research institutions located on the Sea of Japan and the Pacific Ocean. These laboratories are located away from the influences of large rivers and major industrial activity. Measurements were performed daily for the past 30 years (1980s–2010s). The average annual ocean pH for both sites showed generally negative trends. These trends were – 0.0032 and – 0.0068 year–1 (p < 0.001) at the Sea of Japan and Pacific Ocean sites, respectively. The trends were superimposed onto approximately 10-year oscillations, which appear to synchronize with the ocean current periodicity. At the Sea of Japan site, the ocean pH in the summer was higher, and the rate of OA was higher than during other seasons. Our results suggest that seasonality and ocean currents influence OA in the coastal areas of open oceans and can affect the coastal regions of marginal seas.

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Ecological effects of ocean acidification and habitat complexity on reef-associated macroinvertebrate communities

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2013.2479 ◽

2014 ◽

Vol 281 (1775) ◽

pp. 20132479 ◽

Cited By ~ 126

Author(s):

K. E. Fabricius ◽

G. De'ath ◽

S. Noonan ◽

S. Uthicke

Keyword(s):

Ocean Acidification ◽

Habitat Complexity ◽

Atmospheric Carbon Dioxide ◽

Coral Cover ◽

Ecological Effects ◽

Macroinvertebrate Communities ◽

Dead Coral ◽

Marine Communities

The ecological effects of ocean acidification (OA) from rising atmospheric carbon dioxide (CO 2 ) on benthic marine communities are largely unknown. We investigated in situ the consequences of long-term exposure to high CO 2 on coral-reef-associated macroinvertebrate communities around three shallow volcanic CO 2 seeps in Papua New Guinea. The densities of many groups and the number of taxa (classes and phyla) of macroinvertebrates were significantly reduced at elevated CO 2 (425–1100 µatm) compared with control sites. However, sensitivities of some groups, including decapod crustaceans, ascidians and several echinoderms, contrasted with predictions of their physiological CO 2 tolerances derived from laboratory experiments. High CO 2 reduced the availability of structurally complex corals that are essential refugia for many reef-associated macroinvertebrates. This loss of habitat complexity was also associated with losses in many macroinvertebrate groups, especially predation-prone mobile taxa, including crustaceans and crinoids. The transition from living to dead coral as substratum and habitat further altered macroinvertebrate communities, with far more taxa losing than gaining in numbers. Our study shows that indirect ecological effects of OA (reduced habitat complexity) will complement its direct physiological effects and together with the loss of coral cover through climate change will severely affect macroinvertebrate communities in coral reefs.

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Persistent spatial structuring of coastal ocean acidification in the California Current System

Scientific Reports ◽

10.1038/s41598-017-02777-y ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 64

Author(s):

F. Chan ◽

J. A. Barth ◽

C. A. Blanchette ◽

R. H. Byrne ◽

F. Chavez ◽

...

Keyword(s):

Ocean Acidification ◽

Current System ◽

California Current ◽

Coastal Ocean ◽

California Current System ◽

Spatial Structuring

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Ocean Acidification 2.0: Managing our Changing Coastal Ocean Chemistry

BioScience ◽

10.1093/biosci/biu072 ◽

2014 ◽

Vol 64 (7) ◽

pp. 581-592 ◽

Cited By ~ 32

Author(s):

Aaron L. Strong ◽

Kristy J. Kroeker ◽

Lida T. Teneva ◽

Lindley A. Mease ◽

Ryan P. Kelly

Keyword(s):

Ocean Acidification ◽

Coastal Ocean ◽

Ocean Chemistry

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Acclimation to ocean acidification during long‐term CO 2 exposure in the cold‐water coral L ophelia pertusa

Global Change Biology ◽

10.1111/j.1365-2486.2011.02583.x ◽

2011 ◽

Vol 18 (3) ◽

pp. 843-853 ◽

Cited By ~ 155

Author(s):

Armin U. Form ◽

Ulf Riebesell

Keyword(s):

Ocean Acidification ◽

Cold Water ◽

Water Coral

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Experimental reef communities persist under future ocean acidification and warming

10.21203/rs.3.rs-640089/v1 ◽

2021 ◽

Author(s):

Christopher Jury ◽

Keisha Bahr ◽

Evan Barba ◽

Russell Brainard ◽

Annick Cros ◽

...

Keyword(s):

Experimental Study ◽

Species Richness ◽

Coral Reef ◽

Coral Reefs ◽

Ocean Acidification ◽

Community Composition ◽

Functional State ◽

Reef Communities ◽

Paris Climate Agreement

Abstract Coral reefs are among the most sensitive ecosystems affected by ocean acidification and warming, and are predicted to shift from net accreting calcifier-dominated systems to net eroding algal-dominated systems over the coming decades. Here we present a long-term experimental study examining the responses of entire mesocosm coral reef communities to acidification (-0.2 pH units), warming (+ 2°C), and combined future ocean (-0.2 pH, + 2°C) treatments. We show that under future ocean conditions, net calcification rates declined yet remained positive, corals showed reduced abundance yet were not extirpated, and community composition shifted while species richness was maintained. Our results suggest that under Paris Climate Agreement targets, coral reefs could persist in an altered functional state rather than collapse.

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Carbon cycling in the North American coastal ocean: A synthesis

10.5194/bg-2018-420 ◽

2018 ◽

Cited By ~ 2

Author(s):

Katja Fennel ◽

Simone Alin ◽

Leticia Barbero ◽

Wiley Evans ◽

Timotheé Bourgeois ◽

...

Keyword(s):

Ocean Acidification ◽

North American ◽

Inorganic Carbon ◽

Co2 Flux ◽

Carbon Fluxes ◽

Coastal Ocean ◽

Open Ocean ◽

The Arctic ◽

The North ◽

Anthropogenic Carbon

Abstract. A quantification of carbon fluxes in the coastal ocean and across its boundaries, specifically the air-sea, land-to-coastal-ocean and coastal-to-open-ocean interfaces, is important for assessing the current state and projecting future trends in ocean carbon uptake and coastal ocean acidification, but is currently a missing component of global carbon budgeting. This synthesis reviews recent progress in characterizing these carbon fluxes with focus on the North American coastal ocean. Several observing networks and high-resolution regional models are now available. Recent efforts have focused primarily on quantifying net air-sea exchange of carbon dioxide (CO2). Some studies have estimated other key fluxes, such as the exchange of organic and inorganic carbon between shelves and the open ocean. Available estimates of air-sea CO2 flux, informed by more than a decade of observations, indicate that the North American margins act as a net sink for atmospheric CO2. This net uptake is driven primarily by the high-latitude regions. The estimated magnitude of the net flux is 160 ± 80 Tg C/y for the North American Exclusive Economic Zone, a number that is not well constrained. The increasing concentration of inorganic carbon in coastal and open-ocean waters leads to ocean acidification. As a result conditions favouring dissolution of calcium carbonate occur regularly in subsurface coastal waters in the Arctic, which are naturally prone to low pH, and the North Pacific, where upwelling of deep, carbon-rich waters has intensified and, in combination with the uptake of anthropogenic carbon, leads to low seawater pH and aragonite saturation states during the upwelling season. Expanded monitoring and extension of existing model capabilities are required to provide more reliable coastal carbon budgets, projections of future states of the coastal ocean, and quantification of anthropogenic carbon contributions.

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Shell mineralogy of a foundational marine species, Mytilus californianus, over half a century in a changing ocean

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2004769118 ◽

2021 ◽

Vol 118 (3) ◽

pp. e2004769118

Author(s):

Elizabeth M. Bullard ◽

Ivan Torres ◽

Tianqi Ren ◽

Olivia A. Graeve ◽

Kaustuv Roy

Keyword(s):

Ocean Acidification ◽

Historical Data ◽

Mineralogical Composition ◽

Marine Species ◽

Mytilus Californianus ◽

Negative Effects ◽

Saturation State ◽

Long Term Changes ◽

Time Periods

Anthropogenic warming and ocean acidification are predicted to negatively affect marine calcifiers. While negative effects of these stressors on physiology and shell calcification have been documented in many species, their effects on shell mineralogical composition remains poorly known, especially over longer time periods. Here, we quantify changes in the shell mineralogy of a foundation species, Mytilus californianus, under 60 y of ocean warming and acidification. Using historical data as a baseline and a resampling of present-day populations, we document a substantial increase in shell calcite and decrease in aragonite. These results indicate that ocean pH and saturation state, not temperature or salinity, play a strong role in mediating the shell mineralogy of this species and reveal long-term changes in this trait under ocean acidification.

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Ocean carbonate system variability in the North Atlantic Subpolar surface water (1993–2017)

Biogeosciences ◽

10.5194/bg-17-2553-2020 ◽

2020 ◽

Vol 17 (9) ◽

pp. 2553-2577

Author(s):

Coraline Leseurre ◽

Claire Lo Monaco ◽

Gilles Reverdin ◽

Nicolas Metzl ◽

Jonathan Fin ◽

...

Keyword(s):

Surface Water ◽

Ocean Acidification ◽

North Atlantic ◽

Subpolar Gyre ◽

The North ◽

Short Period ◽

North Atlantic Subpolar Gyre ◽

The North Atlantic ◽

Co2 Sink

Abstract. The North Atlantic is one of the major ocean sinks for natural and anthropogenic atmospheric CO2. Given the variability of the circulation, convective processes or warming–cooling recognized in the high latitudes in this region, a better understanding of the CO2 sink temporal variability and associated acidification needs a close inspection of seasonal, interannual to multidecadal observations. In this study, we investigate the evolution of CO2 uptake and ocean acidification in the North Atlantic Subpolar Gyre (50–64∘ N) using repeated observations collected over the last 3 decades in the framework of the long-term monitoring program SURATLANT (SURveillance de l'ATLANTique). Over the full period (1993–2017) pH decreases (−0.0017 yr−1) and fugacity of CO2 (fCO2) increases (+1.70 µatm yr−1). The trend of fCO2 in surface water is slightly less than the atmospheric rate (+1.96 µatm yr−1). This is mainly due to dissolved inorganic carbon (DIC) increase associated with the anthropogenic signal. However, over shorter periods (4–10 years) and depending on the season, we detect significant variability investigated in more detail in this study. Data obtained between 1993 and 1997 suggest a rapid increase in fCO2 in summer (up to +14 µatm yr−1) that was driven by a significant warming and an increase in DIC for a short period. Similar fCO2 trends are observed between 2001 and 2007 during both summer and winter, but, without significant warming detected, these trends are mainly explained by an increase in DIC and a decrease in alkalinity. This also leads to a pH decrease but with contrasting trends depending on the region and season (between −0.006 and −0.013 yr−1). Conversely, data obtained during the last decade (2008–2017) in summer show a cooling of surface waters and an increase in alkalinity, leading to a strong decrease in surface fCO2 (between −4.4 and −2.3 µatm yr−1; i.e., the ocean CO2 sink increases). Surprisingly, during summer, pH increases up to +0.0052 yr−1 in the southern subpolar gyre. Overall, our results show that, in addition to the accumulation of anthropogenic CO2, the temporal changes in the uptake of CO2 and ocean acidification in the North Atlantic Subpolar Gyre present significant multiannual variability, not clearly directly associated with the North Atlantic Oscillation (NAO). With such variability it is uncertain to predict the near-future evolution of air–sea CO2 fluxes and pH in this region. Thus, it is highly recommended to maintain long-term observations to monitor these properties in the next decade.

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