caa a22 4500 605455430 CHVBK 20210128100212.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s10872-015-0302-8 doi (NATIONALLICENCE)springer-10.1007/s10872-015-0302-8 Calcium carbonate saturation and ocean acidification in Tokyo Bay, Japan [Elektronische Daten] [Michiyo Yamamoto-Kawai, Natsuko Kawamura, Tsuneo Ono, Naohiro Kosugi, Atsushi Kubo, Masao Ishii, Jota Kanda] From April 2011 to January 2012, seasonal variation of the aragonite saturation state (Ωar) was observed for the first time in Tokyo Bay, in order to understand the current state of ocean acidification in a highly eutrophicated bay in Japan. Ωar in the bay ranged between 1.55 and 5.12, much greater than observed in offshore waters. At the surface, Ωar was high during summer as a result of photosynthesis with some conflicting effect of freshwater input. At the bottom, Ωar was low during summer due to remineralization of organic matter. Based on an assumption that our observations represent current conditions in Tokyo Bay, it is estimated that the emission of anthropogenic CO2 has already decreased Ωar by 0.6 since the preindustrial period and will further decrease by 1.0-1.6 by the end of this century if emission of CO2 is continued at a high level [representative concentration pathway (RCP) 8.5 scenario]. With other conditions remaining the same, bottom waters of the bay will reach seasonal aragonite undersaturation by 2060-2070. However, because coastal regions have a large interannual variability, we need further observations to evaluate our estimations and future predictions presented here. Nevertheless, it should be safe to say that the larger seasonal variation in Ω causes the Tokyo Bay to reach aragonite undersaturation earlier than offshore regions and such conditions have negative consequences on the variety of calcifying organisms living in Tokyo Bay. Ocean acidification could thus give an additional stress to the ecosystem of the bay, which is now suffering from eutrophication and hypoxia. The Oceanographic Society of Japan and Springer Japan, 2015 Ocean acidification nationallicence Eutrophication nationallicence Calcium carbonate saturation nationallicence Tokyo Bay nationallicence Anthoropgenic CO2 nationallicence Yamamoto-Kawai Michiyo Center for Advanced Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, 108-8477, Tokyo, Japan aut Kawamura Natsuko Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan aut Ono Tsuneo National Research Institute of Fisheries Science, Fisheries Research Agency, Kanagawa, Japan aut Kosugi Naohiro Meteorological Research Institute, Ibaraki, Japan aut Kubo Atsushi Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan aut Ishii Masao Meteorological Research Institute, Ibaraki, Japan aut Kanda Jota Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan aut Journal of Oceanography Springer Japan 71/4(2015-08-01), 427-439 0916-8370 71:4<427 2015 71 10872 https://doi.org/10.1007/s10872-015-0302-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10872-015-0302-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yamamoto-Kawai Michiyo Center for Advanced Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, 108-8477, Tokyo, Japan aut NATIONALLICENCE 700 1- Kawamura Natsuko Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan aut NATIONALLICENCE 700 1- Ono Tsuneo National Research Institute of Fisheries Science, Fisheries Research Agency, Kanagawa, Japan aut NATIONALLICENCE 700 1- Kosugi Naohiro Meteorological Research Institute, Ibaraki, Japan aut NATIONALLICENCE 700 1- Kubo Atsushi Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan aut NATIONALLICENCE 700 1- Ishii Masao Meteorological Research Institute, Ibaraki, Japan aut NATIONALLICENCE 700 1- Kanda Jota Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan aut NATIONALLICENCE 773 0- Journal of Oceanography Springer Japan 71/4(2015-08-01), 427-439 0916-8370 71:4<427 2015 71 10872