Seasonal and interannual variability in particle fluxes of carbon, nitrogen and silicon from time series of sediment traps at Ocean Station P, 1982–1993: relationship to changes in subarctic primary productivity

Wong, C. S.; Whitney, Frank A.; Crawford, David W.; Iseki, Kazuo; Matear, Richard J.; Johnson, William K.; Page, J. S.; Timothy, David A.

doi:10.1016/s0967-0645(99)00082-x

Cited by 187 publications

(120 citation statements)

References 44 publications

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“…9). In most cases, P POC decreases with depth, although in some cases, the maximum P POC in a given profile occurs at 50 or 100 m. P POC fluxes at 100 m range from 0.65 to 7.95 mmol m −2 d −1 ; they are generally higher in summer than winter, and highest at station P4, consistent with previous studies at Line P Wong et al, 1999;Timothy et al, 2013).…”

Section: Th-derived Poc Fluxessupporting

confidence: 89%

Estimates of micro-, nano-, and picoplankton contributions to particle export in the northeast Pacific

et al. 2015

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Abstract. The contributions of micro-, nano-, and picoplankton to particle export were estimated from measurements of size-fractionated particulate 234 Th, 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 234 Th-238 U 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.

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Section: Th-derived Poc Fluxessupporting

confidence: 89%

Estimates of micro-, nano-, and picoplankton contributions to particle export in the northeast Pacific

et al. 2015

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“…However, because of scatter in the data, the various treatments were not statistically different from the control. The total PIC : POC ratio at t 0 and in the control was on the order of 0.04-0.1, consistent with the lower end of values reported for shallow sediment traps at OSP (Wong et al 1999;Wong and Crawford 2002). This ratio increased to almost 0.2 in the ϩFe treatment in which PIC fixation was the highest.…”

Section: Does Addition Of Zn and Fe Together Influence Growth Comparesupporting

confidence: 86%

“…This ratio increased to almost 0.2 in the ϩFe treatment in which PIC fixation was the highest. This ratio has been observed to reach the order of 1 at OSP in sediment traps (Wong and Crawford 2002) and in 14 C uptake experiments (Crawford unpubl. data) when coccolithophores were abundant.…”

Section: Does Addition Of Zn and Fe Together Influence Growth Comparementioning

confidence: 89%

Influence of zinc and iron enrichments on phytoplankton growth in the northeastern subarctic Pacific

Crawford

Lipsen

Purdie

et al. 2003

Limnology & Oceanography

106

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Near-surface seawater from the northeastern subarctic Pacific was incubated on deck for 8 d, supplemented with (1) control, no additions (2) ϩZn (3) ϩFe (4) ϩZnϩFe. Concentrations of total Zn and Fe at time zero (t 0 ) and in the control remained at ϳ0.1-0.2 nmol L Ϫ1. In the control, chlorophyll (Ͻ0.3 mg m Ϫ3 ), 14 C uptake into POC and PIC, and inorganic nutrients all remained relatively constant. Addition of Zn slightly but significantly increased chlorophyll (p Ͻ 0.05), decreased phosphate (p Ͻ 0.01) and nitrate (p Ͻ 0.05), and in P versus E experiments, increased P m Ͼ10-fold and P 2-3-fold. The abundance of small diatoms and coccolithophores was higher in the chl m ϩZn treatment compared to the control. The ϩFe and ϩZnϩFe treatments, compared to the control, both showed Ͼ10-fold increases in chlorophyll and 14 C uptake into POC and PIC and complete removal of nitrate (Յ0.2 mmol m Ϫ3 ). However, differences were observed in size-fractionated data; the ϩZnϩFe treatment had significantly lower percent chlorophyll in the Ͼ20-m fraction (p Ͻ 0.01) and a higher percentage in the 0.2-5-m fraction (p Ͻ 0.01) than the ϩFe treatment. In P versus E experiments, both ϩFe treatments increased P m and ␣ around 100-fold and P and ␣ chl by 5-10-fold compared to the control. The ϩFe treatment showed a slightly higher ␣ chl and slightly chl m lower P than the ϩZnϩFe treatment. Abundance of large diatoms, small diatoms, small flagellates, and coccolchl m ithophores all increased substantially (ϳ7-1,000-fold) in response to Fe addition, whereas dinoflagellate abundance only doubled. The ϩZnϩFe treatment had higher abundances of small diatoms and small flagellates than the ϩFe treatment. We conclude that Zn additions had limited influence on conventional indices of phytoplankton growth compared to Fe, but that there might be subtle influences of Zn that require further attention.

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“…This assumption is reasonable as a first approximation; sediment trap data suggests that POC is the greatest contributor to export flux at 20m at Station P (Wong et al, 1999).…”

Section: Modelmentioning

confidence: 86%

“…A wealth of historical data exist, and Station P was the site of the Subarctic Ecosystem Response to Iron Enrichment Study (SERIES), a synthetic iron fertilization experiment (Boyd et al, 2004). The data show that chlorophyll remains approximately constant throughout the year despite considerable variability within the ecosystem (Wong et al, 1999). Most of the time, the ecosystem at Station P appears to be near, or fluctuating about, steady state, and thus this setting is ideal for the analysis of small perturbations to equilibrium.…”

mentioning

confidence: 99%

Perturbation dynamics of a planktonic ecosystem

Healey¹,

Monahan²,

Ianson³

2009

J Mar Res

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Planktonic ecosystems provide a key mechanism for the transfer of CO 2 from the atmosphere to the deep ocean via the so-called "biological pump".Mathematical models of these ecosystems have been used to predict CO 2 uptake in surface waters, and more recently have been embedded in global climate models. While the equilibrium properties of these models are well studied, less attention has been paid to their response to external perturbations, despite the fact that, as a result of the variability of environmental forcing, such ecosystems are rarely, if ever, in equilibrium. Human induced perturbations to these ecosystems, namely the addition of limiting nutrients (e.g. iron) to areas where nitrate is plentiful to accelerate the biological pump, have been proposed as a solution to reduce atmospheric CO 2 . In this study, linear theory is used to determine the structure of initially "unit-norm" perturbations to state variables of a five state variable ecosystem model in steady state, describing Ocean Station P (50 • N 145 • W) in summer, that optimize either instantaneous export flux of organic matter at fixed times or integrated export as the ecosystem relaxes towards equilibrium. A common feature in the optimization experiments for both instantaneous and integrated flux is the synchronization of the oscillatory behavior between two state variables. Because of these oscillations, there is an indirect contribution to the export flux that is non-intuitive. For all perturbations, it is found that the flux to higher trophic levels is the primary contributor to export flux, and, contrary to expectations, the contribution of aggregation is negligible.

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Seasonal and interannual variability in particle fluxes of carbon, nitrogen and silicon from time series of sediment traps at Ocean Station P, 1982–1993: relationship to changes in subarctic primary productivity

Cited by 187 publications

References 44 publications

Estimates of micro-, nano-, and picoplankton contributions to particle export in the northeast Pacific

Estimates of micro-, nano-, and picoplankton contributions to particle export in the northeast Pacific

Influence of zinc and iron enrichments on phytoplankton growth in the northeastern subarctic Pacific

Perturbation dynamics of a planktonic ecosystem

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