Microbial diversity-informed modelling of polar marine ecosystem functions

Abstract. Heterotrophic marine bacteria utilize organic carbon for growth and biomass synthesis. Thus, their variability is key to the balance between the production and consumption of organic matter and ultimately particle export in the ocean. Here we investigate a potential link between bacterial traits and ecosystem functions in a rapidly changing polar marine ecosystem based on a bacteria-oriented ecosystem model. Using a data-assimilation scheme we utilize the observations of bacterial groups with different physiological states to constrain the group-specific bacterial ecosystem functions. We also investigate the association of the modelled bacterial and other ecosystem functions with eight recurrent modes representative of different bacterial taxonomic traits. High nucleic acid (HNA) bacteria show relatively high cell-specific bacterial production, respiration, and utilization of the semi-labile dissolved organic carbon pool compared to low nucleic acid (LNA) bacteria. Both taxonomy and physiological states of the bacteria are strong predictors of bacterial carbon demand, net primary production, and particle export. Numerical experiments under perturbed climate conditions show overall increased bacterial activity and a potential shift from LNA- to HNA-dominated bacterial communities in a warming ocean. Microbial diversity via different taxonomic and physiological traits informs our ecosystem model, providing insights into key bacterial and ecosystem functions in a changing environment.

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Modeling polar marine ecosystem functions guided by bacterial physiological and taxonomic traits

Biogeosciences ◽

10.5194/bg-19-117-2022 ◽

2022 ◽

Vol 19 (1) ◽

pp. 117-136

Author(s):

Hyewon Heather Kim ◽

Jeff S. Bowman ◽

Ya-Wei Luo ◽

Hugh W. Ducklow ◽

Oscar M. Schofield ◽

...

Keyword(s):

Nucleic Acid ◽

Net Primary Production ◽

Marine Ecosystem ◽

Ecosystem Model ◽

Physiological Traits ◽

Ecosystem Functions ◽

Climate Conditions ◽

West Antarctic ◽

Carbon Demand ◽

Particle Export

Abstract. Heterotrophic marine bacteria utilize organic carbon for growth and biomass synthesis. Thus, their physiological variability is key to the balance between the production and consumption of organic matter and ultimately particle export in the ocean. Here we investigate a potential link between bacterial traits and ecosystem functions in the rapidly warming West Antarctic Peninsula (WAP) region based on a bacteria-oriented ecosystem model. Using a data assimilation scheme, we utilize the observations of bacterial groups with different physiological traits to constrain the group-specific bacterial ecosystem functions in the model. We then examine the association of the modeled bacterial and other key ecosystem functions with eight recurrent modes representative of different bacterial taxonomic traits. Both taxonomic and physiological traits reflect the variability in bacterial carbon demand, net primary production, and particle sinking flux. Numerical experiments under perturbed climate conditions demonstrate a potential shift from low nucleic acid bacteria to high nucleic acid bacteria-dominated communities in the coastal WAP. Our study suggests that bacterial diversity via different taxonomic and physiological traits can guide the modeling of the polar marine ecosystem functions under climate change.

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Skillful prediction of tropical Pacific fisheries provided by Atlantic Niños

10.1101/2021.02.17.431587 ◽

2021 ◽

Author(s):

Iñigo Gómara ◽

Belén Rodríguez-Fonseca ◽

Elsa Mohino ◽

Teresa Losada ◽

Irene Polo ◽

...

Keyword(s):

Large Scale ◽

Southern Oscillation ◽

Marine Ecosystem ◽

Ecosystem Model ◽

Tropical Pacific ◽

Equatorial Atlantic ◽

Climate Conditions ◽

Marine Food Web ◽

Marine Ecosystem Model ◽

The Tropical Pacific

AbstractTropical Pacific upwelling-dependent ecosystems are the most productive and variable worldwide, mainly due to the influence of El Niño Southern Oscillation (ENSO). ENSO can be forecasted seasons ahead thanks to assorted climate precursors (local-Pacific processes, pantropical interactions). However, owing to observational data scarcity and bias-related issues in earth system models, little is known about the importance of these precursors for marine ecosystem prediction. With recently released reanalysis-nudged global marine ecosystem simulations, these constraints can be sidestepped, allowing full examination of tropical Pacific ecosystem predictability. By complementing historical fishing records with marine ecosystem model data, we show herein that equatorial Atlantic Sea Surface Temperatures (SSTs) constitute a superlative predictability source for tropical Pacific marine yields, which can be forecasted over large-scale areas up to 2 years in advance. A detailed physical-biological mechanism is proposed whereby Atlantic SSTs modulate upwelling of nutrient-rich waters in the tropical Pacific, leading to a bottom-up propagation of the climate-related signal across the marine food web. Our results represent historical and near-future climate conditions and provide a useful springboard for implementing a marine ecosystem prediction system in the tropical Pacific.

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The Seasonal Flux and Fate of Dissolved Organic Carbon Through Bacterioplankton in the Western North Atlantic

Frontiers in Microbiology ◽

10.3389/fmicb.2021.669883 ◽

2021 ◽

Vol 12 ◽

Author(s):

Nicholas Baetge ◽

Michael J. Behrenfeld ◽

James Fox ◽

Kimberly H. Halsey ◽

Kristina D. A. Mojica ◽

...

Keyword(s):

Organic Carbon ◽

Dissolved Organic Carbon ◽

North Atlantic ◽

Phytoplankton Bloom ◽

North Atlantic Ocean ◽

Net Primary Production ◽

Deep Ocean ◽

Carbon Demand ◽

Carbon Pump ◽

Biological Carbon Pump

The oceans teem with heterotrophic bacterioplankton that play an appreciable role in the uptake of dissolved organic carbon (DOC) derived from phytoplankton net primary production (NPP). As such, bacterioplankton carbon demand (BCD), or gross heterotrophic production, represents a major carbon pathway that influences the seasonal accumulation of DOC in the surface ocean and, subsequently, the potential vertical or horizontal export of seasonally accumulated DOC. Here, we examine the contributions of bacterioplankton and DOM to ecological and biogeochemical carbon flow pathways, including those of the microbial loop and the biological carbon pump, in the Western North Atlantic Ocean (∼39–54°N along ∼40°W) over a composite annual phytoplankton bloom cycle. Combining field observations with data collected from corresponding DOC remineralization experiments, we estimate the efficiency at which bacterioplankton utilize DOC, demonstrate seasonality in the fraction of NPP that supports BCD, and provide evidence for shifts in the bioavailability and persistence of the seasonally accumulated DOC. Our results indicate that while the portion of DOC flux through bacterioplankton relative to NPP increased as seasons transitioned from high to low productivity, there was a fraction of the DOM production that accumulated and persisted. This persistent DOM is potentially an important pool of organic carbon available for export to the deep ocean via convective mixing, thus representing an important export term of the biological carbon pump.

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Skillful prediction of tropical Pacific fisheries provided by Atlantic Niños

10.5194/egusphere-egu21-3190 ◽

2021 ◽

Author(s):

Iñigo Gómara ◽

Belén Rodríguez-Fonseca ◽

Elsa Mohino ◽

Teresa Losada ◽

Irene Polo ◽

...

Keyword(s):

Large Scale ◽

Southern Oscillation ◽

Marine Ecosystem ◽

Ecosystem Model ◽

Tropical Pacific ◽

Equatorial Atlantic ◽

Climate Conditions ◽

Marine Food Web ◽

Marine Ecosystem Model ◽

The Tropical Pacific

<p>Tropical Pacific upwelling-dependent ecosystems are the most productive and variable worldwide, mainly due to the influence of El Ni&#241;o Southern Oscillation (ENSO). ENSO can be forecasted seasons ahead thanks to assorted climate precursors (local-Pacific processes, pantropical interactions). However, owing to observational data scarcity and bias-related issues in earth system models, little is known about the importance of these precursors for marine ecosystem prediction. With recently released reanalysis-nudged global marine ecosystem simulations, these constraints can be sidestepped, allowing full examination of tropical Pacific ecosystem predictability. By complementing historical fishing records with marine ecosystem model data, we show herein that equatorial Atlantic Sea Surface Temperatures (SSTs) constitute a superlative predictability source for tropical Pacific marine yields, which can be forecasted over large-scale areas up to 2 years in advance. A detailed physical-biological mechanism is proposed whereby Atlantic SSTs modulate upwelling of nutrient-rich waters in the tropical Pacific, leading to a bottom-up propagation of the climate-related signal across the marine food web. Our results represent historical and near-future climate conditions and provide a useful springboard for implementing a marine ecosystem prediction system in the tropical Pacific.</p>

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Review of "Microbial diversity-informed modelling of polar marine ecosystem functions" by H. H. Kim et al.

10.5194/bg-2020-302-rc1 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Microbial Diversity ◽

Marine Ecosystem ◽

Ecosystem Functions

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The assessment of a global marine ecosystem model on the basis of emergent properties and ecosystem function: a case study with ERSEM

Geoscientific Model Development ◽

10.5194/gmd-9-59-2016 ◽

2016 ◽

Vol 9 (1) ◽

pp. 59-76 ◽

Cited By ~ 18

Author(s):

L. de Mora ◽

M. Butenschön ◽

J. I. Allen

Keyword(s):

Ecosystem Function ◽

Large Scale ◽

Marine Ecosystem ◽

Ecosystem Model ◽

Ecosystem Functions ◽

Emergent Properties ◽

Quantitative Metrics ◽

Marine Ecosystem Model ◽

Scale Properties ◽

Meta Analyses

Abstract. Ecosystem models are often assessed using quantitative metrics of absolute ecosystem state, but these model–data comparisons are disproportionately vulnerable to discrepancies in the location of important circulation features. An alternative method is to demonstrate the models capacity to represent ecosystem function; the emergence of a coherent natural relationship in a simulation indicates that the model may have an appropriate representation of the ecosystem functions that lead to the emergent relationship. Furthermore, as emergent properties are large-scale properties of the system, model validation with emergent properties is possible even when there is very little or no appropriate data for the region under study, or when the hydrodynamic component of the model differs significantly from that observed in nature at the same location and time.A selection of published meta-analyses are used to establish the validity of a complex marine ecosystem model and to demonstrate the power of validation with emergent properties. These relationships include the phytoplankton community structure, the ratio of carbon to chlorophyll in phytoplankton and particulate organic matter, the ratio of particulate organic carbon to particulate organic nitrogen and the stoichiometric balance of the ecosystem.These metrics can also inform aspects of the marine ecosystem model not available from traditional quantitative and qualitative methods. For instance, these emergent properties can be used to validate the design decisions of the model, such as the range of phytoplankton functional types and their behaviour, the stoichiometric flexibility with regards to each nutrient, and the choice of fixed or variable carbon to nitrogen ratios.

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The role of ecosystem function and emergent relationships in the assessment of global marine ecosystem models: a case study with ERSEM

Geoscientific Model Development Discussions ◽

10.5194/gmdd-8-6095-2015 ◽

2015 ◽

Vol 8 (8) ◽

pp. 6095-6141

Author(s):

L. de Mora ◽

M. Butenschön ◽

J. I. Allen

Keyword(s):

Ecosystem Function ◽

Large Scale ◽

Marine Ecosystem ◽

Ecosystem Model ◽

Ecosystem Functions ◽

Emergent Properties ◽

Ecosystem Models ◽

Marine Ecosystem Model ◽

Scale Properties ◽

Meta Analyses

Abstract. Ecosystem models are often assessed using quantitative metrics of absolute ecosystem state, but these model-data comparisons are disproportionately vulnerable to discrepancies in the location of important circulation features. An alternative method is to demonstrate the models capacity to represent ecosystem function; the emergence of a coherent natural relationship in a simulation is a strong indication that the model has a appropriate representation of the ecosystem functions that lead to the emergent relationship. Furthermore, as emergent properties are large scale properties of the system, model validation with emergent properties is possible even when there is very little or no appropriate data for the region under study, or when the hydrodynamic component of the model differs significantly from that observed in nature at the same location and time. A selection of published meta-analyses are used to establish the validity of a complex marine ecosystem model and to demonstrate the power of validation with emergent properties. These relationships include the phytoplankton community structure, the ratio of carbon to chlorophyll in phytoplankton and particulate organic matter, the ratio of particulate organic carbon to particulate organic nitrogen and the stoichiometric balance of the ecosystem. These metrics can also inform aspects of the marine ecosystem model not available from traditional quantitative and qualitative methods. For instance, these emergent properties can be used to validate the design decisions of the model, such as the range of phytoplankton functional types and their behaviour, the stoichiometric flexibility with regards to each nutrient, and the choice of fixed or variable carbon to nitrogen ratios.

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