DOI: 10.1002/2016GB005372
Scopus记录号: 2-s2.0-84981340853
论文题名: Influence of plankton community structure on the sinking velocity of marine aggregates
作者: Bach L ; T ; , Boxhammer T ; , Larsen A ; , Hildebrandt N ; , Schulz K ; G ; , Riebesell U
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2016
卷: 30, 期: 8 起始页码: 1145
结束页码: 1165
语种: 英语
英文关键词: aggregates
; ballast
; biological pump
; plankton community structure
; porosity
; sinking velocity
Scopus关键词: aggregate
; ballast water
; biological pump
; carbon fixation
; carbon sink
; coccolith
; community structure
; diatom
; fjord
; food web
; organic matter
; phytomass
; phytoplankton
; porosity
; sediment trap
; velocity profile
; Norway
; Bacillariophyta
; Emiliania huxleyi
英文摘要: About 50 Gt of carbon is fixed photosynthetically by surface ocean phytoplankton communities every year. Part of this organic matter is reprocessed within the plankton community to form aggregates which eventually sink and export carbon into the deep ocean. The fraction of organic matter leaving the surface ocean is partly dependent on aggregate sinking velocity which accelerates with increasing aggregate size and density, where the latter is controlled by ballast load and aggregate porosity. In May 2011, we moored nine 25 m deep mesocosms in a Norwegian fjord to assess on a daily basis how plankton community structure affects material properties and sinking velocities of aggregates (Ø 80–400 µm) collected in the mesocosms' sediment traps. We noted that sinking velocity was not necessarily accelerated by opal ballast during diatom blooms, which could be due to relatively high porosity of these rather fresh aggregates. Furthermore, estimated aggregate porosity (Pestimated) decreased as the picoautotroph (0.2–2 µm) fraction of the phytoplankton biomass increased. Thus, picoautotroph-dominated communities may be indicative for food webs promoting a high degree of aggregate repackaging with potential for accelerated sinking. Blooms of the coccolithophore Emiliania huxleyi revealed that cell concentrations of ~1500 cells/mL accelerate sinking by about 35–40%, which we estimate (by one-dimensional modeling) to elevate organic matter transfer efficiency through the mesopelagic from 14 to 24%. Our results indicate that sinking velocities are influenced by the complex interplay between the availability of ballast minerals and aggregate packaging; both of which are controlled by plankton community structure. ©2016. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/77831
Appears in Collections: 气候变化事实与影响
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作者单位: GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; Hjort Centre for Marine Ecosystem Dynamics, Uni Research Environment, Bergen, Norway; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; Centre for Coastal Biogeochemistry, Southern Cross University, East Lismore, NSW, Australia
Recommended Citation:
Bach L,T,, Boxhammer T,et al. Influence of plankton community structure on the sinking velocity of marine aggregates[J]. Global Biogeochemical Cycles,2016-01-01,30(8)