Long-term ocean acidification trends in coastal waters around Japan

Abstract This 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...

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Bibliographic Details
Published in:Scientific Reports
Main Authors: Ishida, Hiroshi, Isono, Ryosuke S., Kita, Jun, Watanabe, Yutaka W.
Format: Article in Journal/Newspaper
Language:English
Published: Springer Science and Business Media LLC 2021
Subjects:
Online Access:http://dx.doi.org/10.1038/s41598-021-84657-0
http://www.nature.com/articles/s41598-021-84657-0.pdf
http://www.nature.com/articles/s41598-021-84657-0
Description
Summary:Abstract This 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 (1980sā€“2010s). The average annual ocean pH for both sites showed generally negative trends. These trends were ā€“ 0.0032 and ā€“ 0.0068 year ā€“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.