Chinese Science Bulletin

, Volume 57, Issue 9, pp 1062–1068 | Cite as

Coastal acidification in summer bottom oxygen-depleted waters in northwestern-northern Bohai Sea from June to August in 2011

  • WeiDong ZhaiEmail author
  • HuaDe Zhao
  • Nan Zheng
  • Yi Xu
Open Access
Article Oceanology


Dissolved oxygen (DO) and pH in the central part of the Bohai Sea were surveyed in late June and late August, 2011. During the June cruise, the bottom DO was in the range of 215–290 μmol-O2 kg−1 (i.e. 85%–115% of the saturation level), and the bottom pH was in the range of 7.82–8.04 on the total-hydrogen-ion scale. In August, however, both the bottom DO and the pH had significantly declined in the northwestern-northern near-shore areas, where the water depth was no more than 35 m. The lowest bottom DO was 100–110 μmol-O2 kg−1 (only 44%–47% of the June DO values) in the northern near-shore area, where the bottom pH was 7.64–7.68 on the total-hydrogen-ion scale (0.16–0.20 units lower than the June pH value). The largest decreases in DO and in pH were observed in the northwestern near-shore bottom waters, corresponding to declines of 170 μmol-O2 kg−1 (as high as 59% of the June DO value) and 0.29 pH units, respectively. The greatest pH decline of 0.29 pH units meant that the total-hydrogen-ion concentration doubled in the bottom waters from June to August. Based on field measurements of bottom DO/pH combined with a simplified model simulation, we suggest that respiration/remineralization-derived CO2 increased the acidity in the bottom oxygen-depleted waters of northwestern-northern near-shore areas in the Bohai Sea as a result of coastal red tides and/or marine aquaculture. This aquatic chemistry is suggested to be partially responsible for scallop-breeding failures in the northwestern Bohai Sea in summer 2011.


dissolved oxygen pH coastal hypoxia coastal acidification Bohai Sea 


  1. 1.
    Díaz R J, Rosenberg R. Spreading dead zones and consequences for marine ecosystems. Science, 2008, 321: 926–929CrossRefGoogle Scholar
  2. 2.
    Rabalais N N, Turner R E, Justic D, et al. Characterization of Hypoxia: Topic 1 Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico. NOAA Coastal Ocean Program Decision Analysis Series No.15. Silver Spring (MD): NOAA Coastal Ocean Program, 1999Google Scholar
  3. 3.
    Li D J, Zhang J, Huang D J, et al. Oxygen depletion off the Chang-jiang (Yangtze River) Estuary. Sci China Ser D-Earth Sci, 2002, 45: 1137–1146CrossRefGoogle Scholar
  4. 4.
    Zhang J, Gilbert D, Gooday A J, et al. Natural and human-induced hypoxia and consequences for coastal areas: Synthesis and future development. Biogeosciences, 2010, 7: 1443–1467CrossRefGoogle Scholar
  5. 5.
    Wu R S S. Hypoxia: From molecular responses to ecosystem responses. Mar Pollut Bull, 2002, 45: 35–45CrossRefGoogle Scholar
  6. 6.
    Vaquer-Sunyer R, Duarte C M. Thresholds of hypoxia for marine biodiversity. Proc Natl Acad Sci USA, 2008, 105: 15452–15457CrossRefGoogle Scholar
  7. 7.
    Díaz R J, Breitburg D L. The hypoxic environment. In: Richards J G, Farrell A P, Brauner C J, eds. Hypoxia. Fish Physiology, Vol. 27. Burlington: Academic Press, 2009. 1–23Google Scholar
  8. 8.
    Vaquer-Sunyer R, Duarte C M. Temperature effects on oxygen thresholds for hypoxia in marine benthic organisms. Glob Change Biol, 2011, 17: 1788–1797CrossRefGoogle Scholar
  9. 9.
    Zhu B H, Wang G C, Huang B, et al. Effects of temperature, hypoxia, ammonia and nitrate on the bleaching among three coral species. Chin Sci Bull, 2004, 49: 1923–1928Google Scholar
  10. 10.
    Dickson A G, Sabine C L, Christian J R. Guide to best practices for ocean CO2 measurements. PICES Spec Publ 3. 2007Google Scholar
  11. 11.
    Marion G M, Millero F J, Camões M F, et al. pH of seawater. Mar Chem, 2011, 126: 89–96CrossRefGoogle Scholar
  12. 12.
    Pelletier G J, Lewis E, Wallace D W R. CO2SYS.XLS: A calculator for the CO2 system in seawater for Microsoft Excel/VBA. Version 14. Olympia (Washington): Washington State Department of Ecology. 2007Google Scholar
  13. 13.
    Gao K S, Aruga Y, Asada K, et al. Calcification in the articulated coralline alga Carollina pilulifera, with special reference to the effect of elevated CO2 concentration. Mar Biol, 1993, 117: 129–132CrossRefGoogle Scholar
  14. 14.
    Zeebe R E, Zachos J C, Caldeira K, et al. Carbon emissions and acidification. Science, 2008, 321: 51–52CrossRefGoogle Scholar
  15. 15.
    Yuan Y X, Chen J F, Chen B J, et al. Study on adaptability of scallop Chlamys farreri to environment: Effects of salinity and pH on survival, respiration, ingestion and digestion (in Chinese). J Fish Sci Chin, 2000, 7: 73–77Google Scholar
  16. 16.
    Hall-Spencer J M, Rodolfo-Metalpa R, Martin S, et al. Volcanic carbon dioxide vents show ecosystem effects of ocean acidification. Nature, 2008, 454: 96–99CrossRefGoogle Scholar
  17. 17.
    Munday P L, Dixson D L, McCormick M I, et al. Replenishment of fish populations is threatened by ocean acidification. Proc Natl Acad Sci USA, 2010, 107: 12930–12934CrossRefGoogle Scholar
  18. 18.
    Domenici P, Allan B, McCormick M I, et al. Elevated carbon dioxide affects behavioural lateralization in a coral reef fish. Biol Lett, 2011, doi: 10.1098/rsbl.2011.0591Google Scholar
  19. 19.
    Feely R A, Alin S R, Newton J, et al. The combined effects of ocean acidification, mixing, and respiration on pH and carbonate saturation in an urbanized estuary. Estuar Coast Shelf Sci, 2010, 88: 442–449CrossRefGoogle Scholar
  20. 20.
    Byrne R H, Mecking S, Feely R A, et al. Direct observations of basin-wide acidification of the North Pacific Ocean. Geophys Res Lett, 2010, 37: L02601CrossRefGoogle Scholar
  21. 21.
    Cai W J, Hu X P, Huang W J, et al. Acidification of subsurface coastal waters enhanced by eutrophication. Nat Geosci, 2011, 4: 766–770CrossRefGoogle Scholar
  22. 22.
    Lin F A, Lu X W, Luo H, et al. History, status and characteristics of red tide in Bohai Sea (in Chinese). Mar Environ Sci, 2008, 27(Suppl 2): 1–5Google Scholar
  23. 23.
    Zu T T, Bao X W, Xie J, et al. Distribution and variation trends of the environmental factors in the central section of the Bohai Sea (in Chinese). Period Ocean Univ Chin, 2005, 35: 889–894Google Scholar
  24. 24.
    Ning X R, Lin C L, Su J L, et al. Long-term environmental changes and the responses of the ecosystems in the Bohai Sea during 1960–1996. Deep-Sea Res II, 2010, 57: 1079–1091CrossRefGoogle Scholar
  25. 25.
    Zhou F, Huang D J, Su J L. Numerical simulation of the dual-core structure of the Bohai Sea cold bottom water in summer. Chin Sci Bull, 2009, 54: 4520–4528CrossRefGoogle Scholar
  26. 26.
    Chen C C, Chiang K P, Gong G C, et al. Importance of planktonic community respiration on the carbon balance of the East China Sea in summer. Global Biogeochem Cycles, 2006, 20: GB4001CrossRefGoogle Scholar
  27. 27.
    Cui Y, Chen B J, Chen J F. Evaluation on self-pollution of marine culture in the Yellow Sea and Bohai Sea (in Chinese). Chin J Appl Ecol, 2005, 16: 180–185Google Scholar

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© The Author(s) 2012

Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.

Authors and Affiliations

  1. 1.Key Laboratory for Ecological Environment in Coastal Areas (State Oceanic Administration)National Marine Environmental Monitoring CenterDalianChina
  2. 2.State Key Laboratory of Marine Environmental ScienceXiamen UniversityXiamenChina

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