JpGU-AGU Joint Meeting 2017

講演情報

[EJ] ポスター発表

セッション記号 A (大気水圏科学) » A-CG 大気水圏科学複合領域・一般

[A-CG48] [EJ] 北極域の科学

2017年5月24日(水) 15:30 〜 17:00 ポスター会場 (国際展示場 7ホール)

コンビーナ:森 正人(東京大学先端科学技術研究センター)、津滝 俊(宇宙航空研究開発機構)、鄭 峻介(北海道大学 北極域研究センター)、漢那 直也(北海道大学 北極域研究センター)

[ACG48-P16] Interannual variability of bottom oxygen concentration and primary production in the southern Chukchi Sea biological hotspot

*藤原 周1西野 茂人1平譯 享2菊地 隆1 (1.国立研究開発法人海洋研究開発機構、2.北海道大学)

キーワード:生物学的ホットスポット、基礎生産、底層溶存酸素濃度

Hope valley located in the southern Chukchi Sea is known as one of the biological hotspot (southern Chukchi Sea hotspot, SCH). Large benthic biomass in the SCH is supported by high primary productivity of the water column. The dissolved oxygen (DO) sharply decreases at the bottom toward fall as a result of the high sediment community oxygen consumption in the benthic fauna, while it is saturated during winter. We examined annual/inter-annual variability of bottom DO and its mechanisms analyzing ship-board and mooring hydrographic data, satellite derived primary production, and ecosystem model.
The bottom DO showed large interannual variability (104–300 µM) and it was negatively and significantly correlated with cumulative primary production (r = -0.66, p < 0.05). Such negative correlation suggests organic carbon flux to the sea floor drives the activity of the benthic community. Environmental process of decreasing in DO was assessed using one box ecosystem model optimized for the SCH bottom layer. The model also captured bottom DO is sensitive to the flux of primary production from the upper layer. Our results suggest inter-annual variability of primary production is a key factor determining the recent changes in biomass and distribution of the benthic organisms.