TY - JOUR
T1 - Phaeodaria
T2 - An Important Carrier of Particulate Organic Carbon in the Mesopelagic Twilight Zone of the North Pacific Ocean
AU - Ikenoue, Takahito
AU - Kimoto, Katsunori
AU - Okazaki, Yusuke
AU - Sato, Miyako
AU - Honda, Makio C.
AU - Takahashi, Kozo
AU - Harada, Naomi
AU - Fujiki, Tetsuichi
N1 - Funding Information:
We are grateful to the captain, officers, and crews of the research vessel and S1 S8 S2 Hakuho Maru . We also thank the staff of Marine Works Japan Ltd. and Global Ocean Development Inc. for their support during sample collection. All data used in this manuscript are presented in Tables – . Hydrographical data in Table are derived from JAMSTEC data search portal ( http://www.godac.jamstec.go.jp/darwin/cruise/hakuho_maru/kh‐15‐j01/e ). This study was supported by a Sasakawa Scientific Research Grant (29‐701) from The Japan Science Society and by Grants‐in‐Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) 12J04155 to T.I., 26740006 to T.I., and 17K00539 to T.I.
PY - 2019/8/1
Y1 - 2019/8/1
N2 - Phaeodaria, which comprise one group of large, single-celled eukaryotic zooplankton, have been largely ignored by past marine biological studies because Phaeodaria and their delicate skeletons are liable to collapse. As a result, collection and quantification of specimens are difficult, and seasonal changes of phaeodarian abundance have not been thoroughly studied. The transport of biogenic elements by sinking phaeodarians has been estimated for only a few representative species. Sinking particles >1 mm in size and swimmers have traditionally been excluded when estimating sinking particle fluxes. The focus of this study is the large number of phaeodarians among the >1-mm sinking particles collected in the western North Pacific from June 2014 to July 2015. Careful sorting by microscopic examination and chemical analyses revealed that phaeodarians accounted for up to about 10% of the organic carbon in all sinking particles and accounted for a mean of 33% of the organic carbon in the >1-mm sinking particles. The high-standing stocks of phaeodarians at depths of 150–1,000 m in the mesopelagic twilight zone suggested that particles sinking from the euphotic zone as aggregates and fecal pellets can be efficiently exported to the deep sea by the ballasting effect of large phaeodarian particles rich in organic carbon.
AB - Phaeodaria, which comprise one group of large, single-celled eukaryotic zooplankton, have been largely ignored by past marine biological studies because Phaeodaria and their delicate skeletons are liable to collapse. As a result, collection and quantification of specimens are difficult, and seasonal changes of phaeodarian abundance have not been thoroughly studied. The transport of biogenic elements by sinking phaeodarians has been estimated for only a few representative species. Sinking particles >1 mm in size and swimmers have traditionally been excluded when estimating sinking particle fluxes. The focus of this study is the large number of phaeodarians among the >1-mm sinking particles collected in the western North Pacific from June 2014 to July 2015. Careful sorting by microscopic examination and chemical analyses revealed that phaeodarians accounted for up to about 10% of the organic carbon in all sinking particles and accounted for a mean of 33% of the organic carbon in the >1-mm sinking particles. The high-standing stocks of phaeodarians at depths of 150–1,000 m in the mesopelagic twilight zone suggested that particles sinking from the euphotic zone as aggregates and fecal pellets can be efficiently exported to the deep sea by the ballasting effect of large phaeodarian particles rich in organic carbon.
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U2 - 10.1029/2019GB006258
DO - 10.1029/2019GB006258
M3 - Article
AN - SCOPUS:85071452269
VL - 33
SP - 1146
EP - 1160
JO - Global Biogeochemical Cycles
JF - Global Biogeochemical Cycles
SN - 0886-6236
IS - 8
ER -