Estimates of micro-, nano-, and picoplankton contributions to particle export in the northeast Pacific
Autor: | B. L. Mackinson, R. P. Kelly, Gillian Stewart, S.B. Moran, Michael W. Lomas |
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Rok vydání: | 2015 |
Předmět: |
0106 biological sciences
010504 meteorology & atmospheric sciences lcsh:Life Biology 01 natural sciences Ocean gyre lcsh:QH540-549.5 Phytoplankton 14. Life underwater Picoplankton Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences Earth-Surface Processes Total organic carbon geography geography.geographical_feature_category 010604 marine biology & hydrobiology lcsh:QE1-996.5 fungi Biological pump Plankton Particulates lcsh:Geology lcsh:QH501-531 Oceanography Sediment trap lcsh:Ecology sense organs |
Zdroj: | Biogeosciences, Vol 12, Pp 3429-3446 (2015) |
ISSN: | 1726-4189 |
Popis: | The contributions of micro-, nano-, and picoplankton to particle export were estimated from measurements of size-fractionated particulate 234Th, organic carbon, and phytoplankton indicator pigments obtained during five cruises between 2010 and 2012 along Line P in the subarctic northeast Pacific Ocean. Sinking fluxes of particulate organic carbon (POC) and indicator pigments were calculated from 234Th–238U disequilibria and, during two cruises, measured by a sediment trap at Ocean Station Papa. POC fluxes at 100 m ranged from 0.65 to 7.95 mmol m−2 d−1, similar in magnitude to previous results at Line P. Microplankton pigments dominate indicator pigment fluxes (averaging 69 ± 19% of total pigment flux), while nanoplankton pigments comprised the majority of pigment standing stocks (averaging 64 ± 23% of total pigment standing stocks). Indicator pigment loss rates (the ratio of pigment export flux to pigment standing stocks) point to preferential export of larger microplankton relative to smaller nano- and picoplankton. However, indicator pigments do not quantitatively trace particle export resulting from zooplankton grazing, which may be an important pathway for the export of small phytoplankton. These results have important implications for understanding the magnitude and mechanisms controlling the biological pump at Line P in particular, and more generally in oligotrophic gyres and high-nutrient, low-chlorophyll (HNLC) regions where small phytoplankton represent a major component of the autotrophic community. |
Databáze: | OpenAIRE |
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