Changing structure of benthic foraminiferal communities due to declining pH: Results from laboratory culture experiments
The ocean absorbs large amounts of CO2 emitted from human activities, which results in a decrease in seawater pH. Marine calcifying organisms such as foraminifera, are most likely to be affected by this declining pH. In this study, we collected sediments from five stations of different depths (34–73 m) in a continental shelf of the Yellow Sea. The entire benthic foraminiferal communities together with sea sediments were cultured under three constant pHs (8.3, 7.8, and 7.3) for 6 and 12 weeks in the laboratory to study their responses to pH or incubation time. The microcosm’s experimental results obtained showed that most of the foraminiferal community parameters (abundance, species richness, Margalef index, and Shannon-Wiener diversity) decreased significantly (p<0.05) with the decline in pH in all the tested stations. The responses of foraminifera to the decline in pH were species-specific, for instance, Protelphidium tuberculatum and Cribroelphidiumfrigidum were highly sensitive to declining pH and were finally eliminated at low pH, while some species (e.g., Lagenammina atlantica, Verneuilinulla advena, V. propinqua, Haplophragmoides applanata, and H. canariensis) could tolerate low pH and acted as pH-tolerant species. In addition, the proportion of hyaline taxa showed a significant (p<0.05) positive correlation with pH, while agglutinated type showed a negative response. Furthermore, different incubation times (6 and 12 weeks) showed significant effects on the nearshore communities other than the offshore treatments, which were, however, entirely declined after 6 weeks’ incubation under low pH manipulation. Our results indicated that nearshore foraminiferal communities showed rather a resilience to the declining pH and the offshore foraminifera, especially those in the central area of the Yellow Sea Cold Water Mass were found to be more sensitive to the decline in pH in the continental shelf sediments of the Yellow Sea.
KeywordsBenthic foraminifera Community pH Laboratory culture experiment Yellow Sea
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We thank Lina Cao, Man Lyu, Meng Li and the crew of R/V Dongfanghong 2 for help in sampling and technical assistance. We thank two anonymous reviewers for constructive comments on the earlier version of this manuscript. The authors thank to the Jiaozhou Bay Marine Ecosystem Research Station, Chinese Academy of Sciences for sharing the voyage and providing CTD data. This work was supported by the National Natural Science Foundation of China (Grant Nos. 41630965 & 41830539), Monitoring and Protection of Ecology and Environment in the East Pacific Ocean (Granted No. DY135-E2-5), the Senior User Project of RV KEXUE (Grant No. KEXUE2018G27), the Paul Brönnimann Foundation 2014.
- Clarke K R, Gorley R N. 2006. PRIMER v6: User Manual/Tutorial. Plymouth: PRIMER-E LtdGoogle Scholar
- Di Bella L, Ingrassia M, Frezza V, Chiocci F L, Pecci R, Bedini R, Martorelli E. 2018. Spiculosiphon oceana (Foraminifera) a new bio-indicator of acidic environments related to fluid emissions of the Zannone Hydrothermal Field (central Tyrrhenian Sea). Mar Environ Res, 136: 89–98CrossRefGoogle Scholar
- Dlugokencky E, Tans P. 2018. Trends in atmospheric carbon dioxide, National Oceanic & Atmospheric Administration, Earth System Research Laboratory (NOAA/ESRL), available at http://www.esrl.noaa. gov/gmd/ccgg/trends (last access: 5 February 2018)Google Scholar
- GB/T 34656–2017. 2017. Specifications for Marine Sediment Interstitial Biota Survey, National Standard of the People’s Republic of China (in Chinese). Beijing: Standards Press of ChinaGoogle Scholar
- Kurtarkar S R, Nigam R, Saraswat R, Linshy V N. 2011. Regeneration and abnormality in benthic foraminifera Rosalina leei: Implications in reconstructing past salinity changes. Riv Ital Paleontol Stratigr, 117: 189–196Google Scholar
- Liu S, Liu C, Yan P, Huang Z, Peng T, Zhou Y, Ding H. 2013. Research of spectrophotometric pH measurements of sea waters in Jiaozhou Bay and coastal waters of Qingdao (in Chinese). Trans Oceanol Limnol: 108–114Google Scholar
- Orr J C, Fabry V J, Aumont O, Bopp L, Doney S C, Feely R A, Gnanadesikan A, Gruber N, Ishida A, Joos F, Key R M, Lindsay K, Maier-Reimer E, Matear R, Monfray P, Mouchet A, Najjar R G, Plattner G K, Rodgers K B, Sabine C L, Sarmiento J L, Schlitzer R, Slater R D, Totterdell I J, Weirig M F, Yamanaka Y, Yool A. 2005. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature, 437: 681–686CrossRefGoogle Scholar
- Saalim S M, Saraswat R, Suokhrie T, Nigam R. 2018. Assessing the ecological preferences of agglutinated benthic foraminiferal morphogroups from the western Bay of Bengal. Deep-Sea Res Part II-Top Stud Oceanogr, doi: 10.1016/j.dsr2.2018.02.002Google Scholar
- SAS Institute Inc. 2009. SAS/STAT® 9.2 User’s Guide. 2nd ed. Cary, NC: SAS Institute IncGoogle Scholar
- Wei Q, Zhan R, Zang J, Li R. 2010. Distributions and influence factors of the chemical parameters in the Southern Yellow Sea in spring (in Chinese). Mar Sci, 34: 52–60Google Scholar