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Presenters Notified: November 2012

Program Schedule Posted:November 2012

Abstracts Available: January 2013

Meeting:
17-22 February 2013

Fredrick, N. D., Northeastern University, USA, fredrick.n@husky.neu.edu
Berges, J. A., University of Wisconsin-Milwaukee, USA, berges@uwm.edu
Twining, B. S., Bigelow Laboratory for Ocean Sciences, USA, btwining@bigelow.org
Nuñez-Milland, D., University of South Carolina, USA, dnunezm@coastal.edu
Hellweger, F. L., Northeastern University, fhellweger@gmail.com

EXPLORING MECHANISMS OF P CONTENT HETEROGENEITY IN CULTURED PHYTOPLANKTON USING AGENT-BASED MODELING

There can be significant intraspecific individual-level heterogeneity in the internal P content of phytoplankton, which can affect the population-level growth rate. Several mechanisms can create this heterogeneity, including phenotypic variability in various physiological functions (e.g., nutrient uptake rate). Here we use agent-based modeling to explore the contribution of various mechanisms to the heterogeneity in phytoplankton grown in a laboratory culture. Heterogeneity is introduced by randomizing parameters (e.g., maximum uptake rate) of daughter cells at division. The model was calibrated to observations of P quota of individual cells of Thalassiosira pseudonana. Then, a number of simulations with individual mechanisms of heterogeneity turned off were performed. Comparison of the coefficient of variation (CV) of these and the baseline simulation (all mechanisms turned on) provides an estimate of the relative contribution of these mechanisms. The results show that the mechanism with the largest contribution is variability in the maximum internal cell quota parameter, which when removed results in a CV of 0.21 compared to a baseline CV of 0.37. This suggests that nutrient/element storage capabilities/mechanisms are important determinants of intrapopulation heterogeneity.

Oral presentation

Session #:GS08A
Date: 2/19/2013
Time: 10:15