DOI: 10.1029/2018GB005968
论文题名: Nitrogen and Isotope Flows Through the Costa Rica Dome Upwelling Ecosystem: The Crucial Mesozooplankton Role in Export Flux
作者: Stukel M.R. ; Décima M. ; Landry M.R. ; Selph K.E.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2018
卷: 32, 期: 12 语种: 英语
英文关键词: biological pump
; carbon flux
; crustacean
; ecosystem modeling
; euphotic zone
; flux measurement
; food web
; nitrogen isotope
; open ocean
; trophic structure
; upwelling
; zooplankton
; Pacific Ocean
; Pacific Ocean (Equatorial)
; Cetacea
; Costa (ostracode)
; Crustacea
; Protista
; Synechococcus
学科: biological carbon pump
; crustaceans
; diel vertical migration
; linear inverse ecosystem model
; nitrogen cycle
; nitrogen isotopes
中文摘要: The Costa Rica Dome (CRD) is an open-ocean upwelling ecosystem, with high biomasses of picophytoplankton (especially Synechococcus), mesozooplankton, and higher trophic levels. To elucidate the food web pathways supporting the trophic structure and carbon export in this unique ecosystem, we used Markov Chain Monte Carlo techniques to assimilate data from four independent realizations of δ 15 N and planktonic rate measurements from the CRD into steady state, multicompartment ecosystem box models (linear inverse models). Model results present well-constrained snapshots of ecosystem nitrogen and stable isotope fluxes. New production is supported by upwelled nitrate, not nitrogen fixation. Protistivory (rather than herbivory) was the most important feeding mode for mesozooplankton, which rely heavily on microzooplankton prey. Mesozooplankton play a central role in vertical nitrogen export, primarily through active transport of nitrogen consumed in the surface layer and excreted at depth, which comprised an average 36–46% of total export. Detritus or aggregate feeding is also an important mode of resource acquisition by mesozooplankton and regeneration of nutrients within the euphotic zone. As a consequence, the ratio of passively sinking particle export to phytoplankton production is very low in the CRD. Comparisons to similar models constrained with data from the nearby equatorial Pacific demonstrate that the dominant role of vertical migrators to the biological pump is a unique feature of the CRD. However, both regions show efficient nitrogen transfer from mesozooplankton to higher trophic levels (as expected for regions with large fish, cetacean, and seabird populations) despite the dominance of protists as major grazers of phytoplankton. ©2018. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160170
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL, United States; Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL, United States; National Institute of Water and Atmospheric Research, Wellington, New Zealand; Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United States; Department of Oceanography, University of Hawaii at Mānoa, Honolulu, HI, United States
Recommended Citation:
Stukel M.R.,Décima M.,Landry M.R.,et al. Nitrogen and Isotope Flows Through the Costa Rica Dome Upwelling Ecosystem: The Crucial Mesozooplankton Role in Export Flux[J]. Global Biogeochemical Cycles,2018-01-01,32(12)