Microzooplankton regulation of surface ocean POC:PON ratios

Talmy, David; Martiny, Adam C.; Hill, Chris; Hickman, Anna E.; Follows, Michael J.

doi:10.1002/2015gb005273

Cited by 29 publications

(43 citation statements)

References 91 publications

(187 reference statements)

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“…This does not, however, preclude the likelihood that over glacial‐interglacial timescales, the impact on atmospheric CO 2 could be substantially larger as has been suggested by box models (Galbraith & Martiny, ). We also note that as PISCES‐QUOTA zooplankton are considered to have fixed stoichiometry, which may not be the case on the centennial timescale considered (Talmy et al, ), the model may be underestimating the potential contribution of zooplankton to more efficient future carbon export.…”

Section: Discussionmentioning

confidence: 99%

The Impact of Variable Phytoplankton Stoichiometry on Projections of Primary Production, Food Quality, and Carbon Uptake in the Global Ocean

Kwiatkowski

Aumont

Bopp

et al. 2018

Global Biogeochemical Cycles

104

116

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Ocean biogeochemical models are integral components of Earth system models used to project the evolution of the ocean carbon sink, as well as potential changes in the physical and chemical environment of marine ecosystems. In such models the stoichiometry of phytoplankton C:N:P is typically fixed at the Redfield ratio. The observed stoichiometry of phytoplankton, however, has been shown to considerably vary from Redfield values due to plasticity in the expression of phytoplankton cell structures with different elemental compositions. The intrinsic structure of fixed C:N:P models therefore has the potential to bias projections of the marine response to climate change. We assess the importance of variable stoichiometry on 21st century projections of net primary production, food quality, and ocean carbon uptake using the recently developed Pelagic Interactions Scheme for Carbon and Ecosystem Studies Quota (PISCES‐QUOTA) ocean biogeochemistry model. The model simulates variable phytoplankton C:N:P stoichiometry and was run under historical and business‐as‐usual scenario forcing from 1850 to 2100. PISCES‐QUOTA projects similar 21st century global net primary production decline (7.7%) to current generation fixed stoichiometry models. Global phytoplankton N and P content or food quality is projected to decline by 1.2% and 6.4% over the 21st century, respectively. The largest reductions in food quality are in the oligotrophic subtropical gyres and Arctic Ocean where declines by the end of the century can exceed 20%. Using the change in the carbon export efficiency in PISCES‐QUOTA, we estimate that fixed stoichiometry models may be underestimating 21st century cumulative ocean carbon uptake by 0.5–3.5% (2.0–15.1 PgC).

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Section: Discussionmentioning

confidence: 99%

The Impact of Variable Phytoplankton Stoichiometry on Projections of Primary Production, Food Quality, and Carbon Uptake in the Global Ocean

Kwiatkowski

Aumont

Bopp

et al. 2018

Global Biogeochemical Cycles

104

116

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“…et al, 2011) as well as the 200 priming effect (Bianchi, 2011). Zooplankton, phytoplankton and high nutrient levels also reduce POC/PON in coastal waters (Koeve, 2006;Martiny et al, 2013b;Watanabe and Kuwae, 2015;Talmy et al, 2016). The relatively high POC/PON ratio in offshore water is primary caused by small phytoplankton, which is the dominant contributor to POC levels at the ocean surface and has a high POC/PON ratio (Richardson and Jackson, 2007;Puigcorbé et al, 2015).…”

Section: Variations In Poc Pon and Poc/pon With Offshore Distancementioning

confidence: 99%

“…Phytoplankton and microzooplankton growing in low temperatures (subzero) may regulate POC/PON, keeping 285 the value low (Crawford et al, 2015;Talmy et al, 2016), and nitrogen (NO 3 -and NH 4 + ) uptake and light may also play a role (Yun et al, 2012). The impact of temperature on POC/PON in the southern hemisphere (r=-0.31) is relatively low when compared to the northern hemisphere ( Figure 7C).…”

Section: Temperaturementioning

confidence: 99%

“…The impact of temperature on POC/PON in the southern hemisphere (r=-0.31) is relatively low when compared to the northern hemisphere ( Figure 7C). This may indicate that the mineralization of organic carbon occurs at a much higher rate than organic nitrogen with increasing temperature or that terrestrial organic carbon, which has a high POC/PON ratio, is more efficiently kept than phytoplankton-and 290 microzooplankton-derived organic carbon, which has a low POC/PON ratio, with increasing temperature (Sharma, et al, 2015;Porcal et al, 2015;Watanabe and Kuwae, 2015;Crawford et al, 2015;Talmy et al, 2016). …”

Section: Temperaturementioning

confidence: 99%

“…Other factors that regulate C/N on a regional scale include microzooplankton (Talmy et al, 2016), heterotrophic 60 microbes (Crawford et al, 2015) and terrestrial organisms (Jiang, 2013). This variation in C/N increases the uncertainty of global carbon and nitrogen estimation (Babbin, 2014).…”

Section: Introduction 30mentioning

confidence: 99%

See 2 more Smart Citations

Variation pattern of particulate organic carbon and nitrogen in oceans and inland waters

Huang¹,

Ye²,

Hao³

et al. 2017

Preprint

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Modeled Chl:C ratio and derived estimates of phytoplankton carbon biomass and its contribution to total particulate organic carbon in the global surface ocean

Arteaga

Pahlow

Oschlies

2016

Global Biogeochemical Cycles

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Chlorophyll (Chl) is a distinctive component of autotrophic organisms, often used as an indicator of phytoplankton biomass in the ocean. However, assessment of phytoplankton biomass from Chl relies on the accurate estimation of the Chl:carbon(C) ratio. Here we present global patterns of Chl:C ratios in the surface ocean obtained from a phytoplankton growth model that accounts for the optimal acclimation of phytoplankton to ambient nutrient, light, and temperature conditions. The model agrees largely with observed/expected global patterns of Chl:C. Combining our Chl:C estimates with satellite Chl and particulate organic carbon (POC), we infer phytoplankton C concentration in the surface ocean and its contribution to the total POC pool. Our results suggest that the portion of POC corresponding to living phytoplankton is higher in subtropical latitudes and less productive regions (∼30–70%) and decreases to ∼10–30% toward high latitudes and productive regions. An important caveat of our model is the lack of iron limiting effects on phytoplankton physiology. Comparison of our predicted phytoplankton biomass with an independent estimate of total POC reveals a positive correlation between nitrate concentrations and nonphotosynthetic POC in the surface ocean. This correlation disappears when a constant Chl:C is applied. Our analysis is not constrained by assumptions of constant Chl:C or phytoplankton:POC ratio, providing a novel independent analysis of phytoplankton biomass in the surface ocean. These results highlight the importance of accounting for the variability in Chl:C and its application in distinguishing the autotrophic and heterotrophic components in the assemblage of the marine plankton ecosystem.

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Microzooplankton regulation of surface ocean POC:PON ratios

Cited by 29 publications

References 91 publications

The Impact of Variable Phytoplankton Stoichiometry on Projections of Primary Production, Food Quality, and Carbon Uptake in the Global Ocean

The Impact of Variable Phytoplankton Stoichiometry on Projections of Primary Production, Food Quality, and Carbon Uptake in the Global Ocean

Variation pattern of particulate organic carbon and nitrogen in oceans and inland waters

Modeled Chl:C ratio and derived estimates of phytoplankton carbon biomass and its contribution to total particulate organic carbon in the global surface ocean

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