High-Frequency Dynamics of Ocean pH: A Multi-Ecosystem Comparison

By Gretchen E. Hofmann, J. Smith, Kenneth S. Johnson, U. Send, L. Levin, Fiorenza Micheli, A. Paytan, N. Price, B. Peterson, Y. Takeshita and 8 more. PLoS ONE, 2011

971 citations recorded by the source corpus.

The effect of Ocean Acidification (OA) on marine biota is quasi-predictable at best. While perturbation studies, in the form of incubations under elevated pCO2, reveal sensitivities and responses of individual species, one missing link in the OA story results from a chronic lack of pH data specific to a given species' natural habitat. Here, we present a compilation of continuous, high-resolution time series of upper ocean pH, collected using autonomous sensors, over a variety of ecosystems ranging from polar to tropical, open-ocean to coastal, kelp forest to coral reef. These observations reveal a continuum of month-long pH variability with standard deviations from 0.004 to 0.277 and ranges spanning 0.024 to 1.430 pH units. The nature of the observed variability was also highly site-dependent, with characteristic diel, semi-diurnal, and stochastic patterns of varying amplitudes. These biome-specific pH signatures disclose current levels of exposure to both high and low dissolved CO2, often demonstrating that resident organisms are already experiencing pH regimes that are not predicted until 2100. Our data provide a first step toward crystallizing the biophysical link between environmental history of pH exposure and physiological resilience of marine organisms to fluctuations in seawater CO2. Knowledge of this spatial and temporal variation in seawater chemistry allows us to improve the design of OA experiments: we can test organisms with a priori expectations of their tolerance guardrails, based on their natural range of exposure. Such hypothesis-testing will provide a deeper understanding of the effects of OA. Both intuitively simple to understand and powerfully informative, these and similar comparative time series can help guide management efforts to identify areas of marine habitat that can serve as refugia to acidification as well as areas that are particularly vulnerable to future ocean change.

Subfields: Ecology, Oceanography

View Paper: https://www.semanticscholar.org/paper/56022bce797e62a7931dc9b6ac6b9ab5b949bddb

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Citations in the corpus

Interactive effects of ocean acidification and temperature on two scleractinian corals from Moorea, French Polynesia (2012, background): “rus would likely undergo relative shifts in species abundance depending on the regimes of temperature and pCO2, neither of which are stable over space or time in shallow water (e.g., Leichter et al., 2006; Gagliano et al., 2011; Hofmann et al., 2011).”
How good are we at assessing the impact of ocean acidification in coastal systems? Limitations, omissions and strengths of commonly used experimental approaches with special emphasis on the neglected role of fluctuations (2016, background): “Biological activities such as respiration and photosynthesis lead to fluctuations at frequencies of seconds toweeks (Hofmann et al. 2011; Buapet et al. 2013).”
Biological mechanisms supporting adaptation to ocean acidification in coastal ecosystems (2015, neutral): “Coastal oceans are characterized by large variability in carbonate chemistry (Aufdenkampe et al., 2011; Hofmann et al., 2011; Mercado and Gordillo, 2011; Duarte et al., 2013), which may span”
Interactive effects of elevated temperature and pCO2 on early-life-history stages of the giant kelp Macrocystis pyrifera (2014, methodology): “The high pCO2 treatment reflects extreme records reported for natural environmental conditions during upwelling events (Hofmann et al., 2011); in this case, ~1800 μatm of pCO2 (pH ~7.5) was the high exposure level and ~370 μatm (pH ~8.0) was used to represent the lower exposure level.”
Resiliency of juvenile walleye pollock to projected levels of ocean acidification (2012, background): “…the results from laboratory exposures to elevated CO2 for predicting species’ responses to ocean acidification, it is critical to consider life history and natural patterns of environmental variation experienced by the species or population (Hofmann et al. 2011, Mc Elhaney & Busch in press).”
Appropriate pCO2 treatments in ocean acidification experiments (2013, background): “Equating current and projected atmospheric pCO2 concentrations with OA scenarios could lead to misleading interpretations of experimental results (Andersson and Mackenzie 2011; Hofmann et al. 2011).”
Offspring sensitivity to ocean acidification changes seasonally in a coastal marine fish (2014, background): “…a growing number of publications, our study highlighted the importance of diel and seasonal CO2 fluctuations that many ecologically and economically important organisms regularly experience in coastal habitats (Hendriks et al. 2010, Hofmann et al. 2011, McElhany & Busch 2012, Duarte et al. 2013).”
Adaptation and the physiology of ocean acidification (2013, neutral): “2, Hofmann et al. 2011).”
Impact of ocean acidification and warming on the Mediterranean mussel (Mytilus galloprovincialis) (2014, background): “Moreover, all these studies considered stable pH and/or temperature conditions although large daily and/or seasonal variations in these parameters are common features of coastal sites (Hofmann et al., 2011).”
Effects of ocean acidification on hatch size and larval growth of walleye pollock (Theragra chalcogramma) (2013, background): “Midwater pelagic areas are more physiochemically stable than shallow coastal waters which can exhibit significant natural, short-term variation in CO2 levels (Hofmann et al., 2011; McElhany and Busch, 2012).”
Understanding the responses of ocean biota to a complex matrix of cumulative anthropogenic change (2012, background): “Ocean chemistry often differs in fundamental ways from that of fresh - water, e.g. carbonate chemistry in the ocean is highly buffered (Dickson 1992) and hence pH variability is less than in most freshwater systems (Toupin 2005, Hofmann et al. 2011).”
Applying organized scepticism to ocean acidification research (2016, background): “…seasonal (blooms), interannual (higher temperatures), horizontal (coastal upwelling areas, high turbidity zones), and vertical (deep vs. surface waters) ranges in these can be extensive (e.g. Wootton et al., 2008; Hofmann et al., 2011; Waldbusser and Salisbury, 2014; Kapsenberg et al., 2015).”
Effects of seawater pCO2 and temperature on shell growth, shell stability, condition and cellular stress of Western Baltic Sea Mytilus edulis (L.) and Arctica islandica (L.) (2013, background): “Considering the different coastal areas in sum, a large number of the World’s coastal regions are subject to at least occasionally strong natural acidification (Hofmann et al. 2011).”