Ocean Ecosystems and Ecology

Main content

global coccolithophore biomass  
global coccolithophore biomass (ugC/L) modeled using an artificial neural network analysis based environmental variables and species observations from microscopy (O'Brien, C., unpublished)

Planktonic marine ecosystems today face a host of environmental perturbations, both natural and anthropogenic. The ability to accurately quantify and forecast effects of modern climate change on ocean ecology is still in its nascent stages, not only due to limited spatial and temporal global coverage of ecological field data, but also due to a fragmented understanding of how plankton communities both respond to, and influence, the biogeochemistry of the marine environment. Phytoplankton communities are increasingly categorized with respect to their “functional” biogeochemical roles, such as “silicifiers” (e.g., diatoms), “calcifiers” (e.g., coccolithophores), “nitrogen fixers” (e.g., cyanobacterium Trichodesmium), “DMS-producers” (e.g., haptophyte Phaeocystis), in order to reduce complexity and constrain the biogeochemical dynamics of plankton in global models. However, even such classifications may overlook aspects of biodiversity in planktonic ecosystems that are vulnerable to environmental change, the feedbacks of which substantially impact primary production, grazing and export of organic carbon.

In the Ocean Ecosystems and Ecology group we investigate distribution, diversity and dynamics of plankton on species-level to functional group scales, and on regional to global scales. Our current projects employ a range of data, statistical tools and models to explore the coupling between plankton biogeography, marine ecosystem functioning and global biogeochemical cycles, including potential feedbacks to the climate system. In parallel, our efforts entail the application and improvement of global and regional marine ecosystems models as part of the Marine Ecosystem Model Intercomparison Project (MAREMIP) and Regional Ocean Modeling System (ROMS) communities. All of our current projects rely on the use of global marine biomass data from the Marine Ecosystem Data atlas (MAREDAT), which was in part assembled by members of this group.

Current projects:

  • Statistical modeling of global coccolithophore diversity and biomass
  • Construction of global climatologies of phytoplankton community structure from chemotaxonomic analysis of global HPLC pigment data
  • Investigation of the susceptibility and biogeochemical impact of diatom-coccolithophore coexistence under changing environmental conditions in the past, present and future Southern Ocean using ROMS coupled to the Biogeochemical Elemental Cycling (BEC) model
  • Species Distribution Modeling of ecological niches of marine phytoplankton to provide a theoretical description of plankton diversity in models
  • Intercomparison of marine ecosystem model performances to investigate controls on export production
  • Investigation of plankton functional type dominance from Dynamic Green Ocean Models and remote sensing algorithms

Key publications:

Laufkoetter, C., Vogt, M., Gruber, N., 2013. Long-term trends in ocean plankton production and particle export between 1960 – 2006. Biogeosciences, 10, 7373-7393, doi:10.5194/bg-10-7373-2013.

Le Quere, C., Harrison, S., et al., 2005. Ecosystem dynamics based on plankton functional types for global ocean biogeochemistry models. Glob. Change Biol. 11, 2016 – 2040.

O’Brien, C. J., Peloquin, J. A., Vogt, M., et al., 2013. Global marine plankton functional type biomass distributions: coccolithophores. Earth Syst. Sci. Data, 5, 259 – 276, doi:10.5194/essd-5-259-2013.

Peloquin, J., Swan, C., Gruber, N., et al., 2014. The MAREDAT global database of high performance liquid chromatography marine pigment measurements. Earth Syst. Sci. Data 5, 109 – 123, doi:10.5194/essd-5-109-2013.

Vogt, M., O’Brien, C., Peloquin, J., et al., 2012. Global marine plankton functional type biomass distributions: Phaeocystis spp. Earth Syst. Sci. Data 4, 107 – 120, doi:10.5194/essd-4-107-2012.

 
 
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