Articles | Volume 13, issue 6
Biogeosciences, 13, 1767–1786, 2016
Biogeosciences, 13, 1767–1786, 2016
Reviews and syntheses
23 Mar 2016
Reviews and syntheses | 23 Mar 2016

Reviews and Syntheses: Ocean acidification and its potential impacts on marine ecosystems

Khan M. G. Mostofa1,2,9, Cong-Qiang Liu2, WeiDong Zhai3, Marco Minella4,5, Davide Vione4,5, Kunshan Gao6, Daisuke Minakata7, Takemitsu Arakaki8, Takahito Yoshioka9,a, Kazuhide Hayakawa10, Eiichi Konohira9,b, Eiichiro Tanoue9,11, Anirban Akhand12, Abhra Chanda12, Baoli Wang2, and Hiroshi Sakugawa13 Khan M. G. Mostofa et al.
  • 1Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
  • 2State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
  • 3Institute of Marine Science and Technology, Shandong University, Ji-nan 250100, China
  • 4Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy
  • 5Centro Interdipartimentale NatRisk, Via Leonardo da Vinci 44, 10095 Grugliasco (TO), Italy
  • 6State Key Laboratory of Marine Environmental Science (B-606), Xiamen University, Daxue Rd 182, Xiamen, Fujian 361005, China
  • 7Department of Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA
  • 8Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru, Nishihara-cho, Okinawa 903-0213, Japan
  • 9Institute for Hydrospheric–Atmospheric Sciences, Nagoya University, Nagoya, Japan
  • 10Lake Biwa Environmental Research Institute, Shiga Prefecture, Ohtsu 520-0806, Japan
  • 11Hydrospheric Atmospheric Research Center, Nogoya University, Nagoya, Japan
  • 12School of Oceanographic Studies, Jadavpur University, Jadavpur, Kolkata 700032, West Bengal, India
  • 13Graduate School of Biosphere Science, Department of Environmental Dynamics and Management, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima 739-8521, Japan
  • aPresent address: Field Science Education and Research Center, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
  • bPresent address: DLD inc., 2435 Kamiyamada, Takatomachi, Ina, Nagagano 396-0217, Japan

Abstract. Ocean acidification, a complex phenomenon that lowers seawater pH, is the net outcome of several contributions. They include the dissolution of increasing atmospheric CO2 that adds up with dissolved inorganic carbon (dissolved CO2, H2CO3, HCO3, and CO32−) generated upon mineralization of primary producers (PP) and dissolved organic matter (DOM). The aquatic processes leading to inorganic carbon are substantially affected by increased DOM and nutrients via terrestrial runoff, acidic rainfall, increased PP and algal blooms, nitrification, denitrification, sulfate reduction, global warming (GW), and by atmospheric CO2 itself through enhanced photosynthesis. They are consecutively associated with enhanced ocean acidification, hypoxia in acidified deeper seawater, pathogens, algal toxins, oxidative stress by reactive oxygen species, and thermal stress caused by longer stratification periods as an effect of GW. We discuss the mechanistic insights into the aforementioned processes and pH changes, with particular focus on processes taking place with different timescales (including the diurnal one) in surface and subsurface seawater. This review also discusses these collective influences to assess their potential detrimental effects to marine organisms, and of ecosystem processes and services. Our review of the effects operating in synergy with ocean acidification will provide a broad insight into the potential impact of acidification itself on biological processes. The foreseen danger to marine organisms by acidification is in fact expected to be amplified by several concurrent and interacting phenomena.

Final-revised paper