LONG-TERM GOALS

Localized concentrations of plankton (i.e. patches) alter the optical and acoustical properties of the water column and can have significant ramifications for the ecological dynamics of marine communities. The goal of this research is to develop a mechanistic understanding and predictive capability of the relative importance of biological in the formation, persistence, and decline of plankton patches. This goal is addressed by concurrent characterization of physical water column structure, advective fluid flow, and plankton population rates of growth and grazing. OBJECTIVES The objective of the funded work is to quantify the relative importance of environmental and ecological processes to plankton patch formation in the coastal ocean. These objectives are addressed by simultaneously quantifying (1) spatial and temporal characteristics of large plankton patches (2) fluid flow associated with the patches using Lagrangian drifters, and (3) the plankton population dynamics through simultaneous measurements of phytoplankton growth and mortality rates as measured by changes in Chl a and (4) statistical analysis of environmental and biological factors associated with phytoplankton patch presence and intensity. APPROACH The methodological approach of this research is to combine high-resolution analysis of in-situ plankton distributions and the chemical, physical and biological conditions they occur in with laboratory-based measurements of plankton abundance, productivity, and grazer-induced mortality rates. Upon discovery, plankton patches are seeded with Lagrangian drifters and revisited at daily intervals to track the horizontal position of patches and quantify the rates of advection. This research utilizes methods widely used in biological oceanography as well as more recent approaches establishe