Mesoscale Variability

### Mesoscale Variability in Biological Responses

How are biological processes and the characteristics of planktonic populations affected by mesoscale features and dynamics in the CCS?

- What physical forcing determines the strength, frequency and location of mesoscale jets and eddies?

- How and to what extent do zooplankton use the small-scale three-dimensional circulation near mesoscale fronts and eddies to modify an otherwise passive transport?

- How do differences in local transport between small and large upwelling centers impact the survival of larvae and recruitment to the adult population?

The important biological processes include primary production; growth, mortality and the genetic composition of zooplankton (holoplankton, meroplankton and ichthyoplankton); transport, retention and recruitment; and links between secondary production, especially reproductive output, and the subsequent recruitment success of fish and benthos. Mesoscale physical processes expected to control these biological variables, and subject to change with changing climate, include frontal dynamics, locally intense cross-shelf transport, eddy recirculation, stratification and vertical shear. The patterns of behavior (vertical and horizontal swimming) by which plankton use mesoscale features to modify their transport need to be understood in order to incorporate this behavior into individual based biophysical models. Only by realistically including the interaction of the mesoscale circulation with the behaviorally-modified transport of larval populations will the models be able to predict the consequences of changes in the mesoscale circulation which may accompany climate change.