日本地球惑星科学連合2021年大会

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[E] 口頭発表

セッション記号 B (地球生命科学) » B-PT 古生物学・古生態学

[B-PT01] 生物鉱化作用(バイオミネラリゼーション)と古環境プロキシー

2021年6月6日(日) 13:45 〜 15:15 Ch.26 (Zoom会場26)

コンビーナ:豊福 高志(国立研究開発法人海洋研究開発機構)、北里 洋(国立大学法人東京海洋大学)、Bijma Jelle(アルフレッドウェゲナー極域海洋研究所)、廣瀬 孝太郎(早稲田大学  大学院創造理工学研究科 地球・環境資源理工学専攻)、座長:豊福 高志(国立研究開発法人海洋研究開発機構)、北里 洋(国立大学法人東京海洋大学)、廣瀬 孝太郎(早稲田大学  大学院創造理工学研究科 地球・環境資源理工学専攻)、Jelle Bijma(アルフレッドウェゲナー極域海洋研究所)

13:48 〜 14:03

[BPT01-02] 底生有孔虫群集の多様性を海洋景観生態学の視点から評価する試み

*北里 洋1 (1.国立大学法人東京海洋大学)

キーワード:海洋景観生態学、微小空間分布、底生有孔虫、生物多様性、生鉱物化作用

Foraminifers secrete various chemicals for chamber walls. They are calcium carbonates such as calcite, aragonite, Mg-calcite, organic compounds for agglutinated chambers and/or organic cemented test walls. Foraminiferal test walls basically form according to genetic information. However, same test group is tended to gather at specific microenvironments. For instance, turf shaped algal microhabitat such as coralline algae at rocky shore is composed of both frond and thallus parts as microhabitat. Frond part is open space where fresh seawater moves inbetween one frond and to the other. Elphidium crispum, Pararotalia nipponica and Patellina corrugate and other calcareous foraminifers dwell at frondal surface. In contrast, thallus part is muddy and high concentration of organic matters. The thallus part shows less oxygenated than frondal part as the space is close. Microbial cascades are developed at thallus part. Minor elements such as Mg or Sr are relatively high in sediment. Soft-shelled forms such as Allogromia, gromiid, agglutinated forms and miliolids groups with high magnesian calcite tests flourish at the thallus part. Most of foraminifers dwelled at muddy environments are mobile mode of life.
Microhabitat segregation and microenvironmental differences may cause similar biomineralization of benthic foraminiferal tests. I would like to stress that micro-seascape should be important to characterize benthic foraminiferal communities.