SS1.04 Small-scale Biophysical Coupling in Plankton Ecology
Date: Thursday, June 13, 2002
Time: 3:15:00 PM
Location: Esquimalt
 
GrünbaumD, School of Oceanography, University of Washington, Seattle, WA, USA, grunbaum@ocean.washington.edu
 
ASSESSING THE RELATIVE IMPORTANCE OF MOVEMENT AND DEMOGRAPHY IN THE DYNAMICS OF SPATIALLY AND TEMPORALLY HETEROGENEOUS PLANKTON POPULATIONS
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Individual-level observations of foraging and other movement behaviors in copepods, dinoflagellates and other zooplankton have greatly improved our understanding of how their distributions respond to spatially and temporally variable resources. Many organisms can climb environmental gradients to locate resource patches. However, sensory and biomechanical constraints imply that some resource patches are accessible while others are not. The spatio-temporal scales at which resources occur largely determine whether patches are available to specific zooplankton consumers, and if so whether changes in consumer densities within patches are driven primarily by movement (emigration, immigration) or by demographic processes (reproduction, mortality). Integrating individual-level responses with circulation-level studies of planktonic distributions requires summarizing the cumulative effect of local-scale movement and demography (e.g, recruitment to a resource patch) on large-scale primary production and population dynamics. I present a modeling analysis that combines taxon-specific, individual-level traits (e.g. foraging behaviors) and landscape-level features (spatio-temporal characteristics of resource patches). The results are data-based indices of ecological regimes, that summarize whether consumer movement, consumer demography, and/or resource dynamics are likely to be dominant in determining overall ecological dynamics.