Modeling the collective behavior of unsteadily swimming zooplankton, Research Area 3.3 Biomathematics
Technical Report,01 Jan 2016,30 Apr 2017
University of Hawaii - Research Services Honolulu United States
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Major Goals Predicting the large-scale and long-term collective behavior of a population of swimming organisms in terms of their small-scale intermittent movement is a major challenge in biomathematics. This project took a mechanistic approach toward understanding the unsteady dynamics of zooplankton known as copepods. Major goals of the project were to i develop a mathematical model that accounts for sudden changes in velocity as commonly observed in the behavior of zooplankton ii perform laboratory experiments to assess the validity of themodel assumptions and predictions iii to gain a general understanding of the dynamics across different length and time scales. The initial plan was to represent each swimming organism as an individual agent alternating randomly between two arbitrary speeds in the model. The objective was to obtain analytical expressions for important statistical quantities such as the effective diffusivity. A careful analysis of the model led to an exciting discovery that the results could be obtained in a more general setting, where individuals switch stochastically not only between two but any number of distinct speeds. However, preliminary experiments showed that the changes in speed are not entirely random as initially assumed. Instead they are governed importantly by sensory cues from the external environment. Thus the focus of the project shifted toward identifying the key sensory cues that trigger behavioral responses and how such responses in turn modify the external environment.
- Statistics and Probability