Title: Integration of environmental variation by the marine plankton community
Abstract: Marine plankton populations often exhibit low frequency variations occurring on interannual and longer timescales. This type of variability in the plankton may be driven by external environmental variations, such as El Niño or the Pacific Decadal Oscillation. However, an alternative and still largely unsubstantiated hypothesis contends that stochastic environmental noise, after filtering through plankton food webs, can produce low-frequency population dynamics. Here, using time series data for 150 phytoplankton, microzooplankton, and mesozooplankton taxa from the English Channel, we assess the degree to which this type of ecological filtering of environmental noise occurs in marine plankton communities. Consistent with this alternative view of the drivers of plankton population dynamics, we find that marine zooplankton experience proportionally more low frequency variability than their shorter-lived phytoplankton prey. However, the capacity for internal food dynamics in the English Channel to produce low frequency variability in populations appears limited, suggesting that large and long-lived anomalies in plankton communities are driven by variations in external environmental, rather intrinsic food web, dynamics.
Bio: Andrew Barton is an Assistant Professor at the Scripps Institution of Oceanography and at the section of Ecology, Behavior and Evolution of the University of California, San Diego. His research combines observational and numerical modeling perspectives to understand the fundamental mechanisms that regulate microbial population dynamics, community structure, biogeography, and biodiversity in the ocean. Barton investigates how changes in Earth’s climate, including natural variability and long-term changes driven by human activities, have the potential to alter microbial species distributions and community composition through time. He received a B.A. in Science of Earth Systems from Cornell University (2000) and a Ph.D. in Climate Physics and Chemistry from Massachusetts Institute of Technology (2011). He was an NSF International Research Postdoctoral Fellow hosted jointly between Duke University and the University of Liverpool in the United Kingdom, and later was an Associate Research Scholar at the Geophysical Fluid Dynamics Laboratory at Princeton University.