Changing structure of benthic foraminiferal communities due to declining pH:Results from laboratory culture experiments  

作　　者：Shuaishuai DONG Yanli LEI Tiegang LI Zhimin JIAN 

机构地区：[1]Laboratory of Marine Organism Taxonomy and Phylogeny,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China [2]Key Laboratory of Marine Sedimentology and Environmental Geology,First Institute of Oceanography,MNR.Qingdao 266061,China [3]State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China [4]Laboratoiy for Marine Biology and Biotechnology,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266061,China [5]University of Chinese Academy of Sciences,Beijing 100049,China [6]Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China

出　　处：《Science China Earth Sciences》2019年第7期1151-1166,共16页中国科学（地球科学英文版）

基　　金：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 Bronnimann Foundation 2014。

摘　　要：The ocean absorbs large amounts of CO_2 emitted from human activities, which results in a decrease in seawater p H.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 p H 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 p H manipulation. Our results indicated that nearshore foraminiferal communities showed rather a resilience to the declining p H 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.The ocean absorbs large amounts of CO_2 emitted from human activities, which results in a decrease in seawater p H.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 p H 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 p H manipulation. Our results indicated that nearshore foraminiferal communities showed rather a resilience to the declining p H 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.

关 键 词：Benthic foraminifera COMMUNITY PH Laboratory culture experiment Yellow Sea 

分 类 号：P[天文地球]