SEMINAR: SEMINAR MBF 602 - Adam Greer - Friday 2-4-11, 1 pm S/A 103

["Adam T. Greer" <agreer@rsmas.miami.edu>]

Fine scale sampling of Thin Layers in Monterey Bay and Massachusetts Bay using the In Situ Ichthyoplankton Imaging System

Abstract:

Variation in larval survival can have a direct influence on recruitment, and therefore adult population abundance. Larval fishes, as well as their predators and prey, are distributed non-randomly, but these patches and the physical features influencing them are not well described due to the low sampling resolution of plankton net systems. Thin layers are small-scale biophysical features (centimeters to five meters in the vertical thickness) consisting of high concentrations of plankton, and they may be sites of increased larval fish feeding and/or predation.  In order to describe the spatio-temporal relationships of organisms in the presence of thin layers, we deployed the In Situ Ichthyoplankton Imaging System (ISIIS) in two separate locations: Monterey Bay and Massachusetts Bay.  These two study locations were chosen for their different hydrographic regimes, reflecting the diversity of environments in which thin layers can form.  Preliminary data from Monterey Bay shows vertically-discrete, high concentrations of chlorophyll fluorescence, which correspond to high backscatter signal from the 200 kHz acoustic data.  There was also an abrupt change in marine snow characteristics with depth, as described by image histogram statistics from the ISIIS imagery.  In Massachusetts Bay, ISIIS captured a thin layer of copepods as dense as 150,000 per m³ located approximately 10 m above the chlorophyll maximum. The composition of the thin layers, and their location relative to the chlorophyll maximum, demonstrates that different biological processes may be at work between these two sites.  Future work will be aimed to understand the changes in meso-zooplankton and larval fish communities over the different time periods of sampling and relating the information extracted from images to bongo and acoustic data.

 
Adam Greer

B.A. Ecology, Evolution, and Organismal Biology, Vanderbilt University 2007

Entered PhD program Fall of 2008

Advisor: Bob Cowen

 

-- 
Adam T. Greer
Graduate Research Assistant
Rosenstiel School of Marine and Atmospheric Science
University of Miami
221 South Grosvenor
agreer@rsmas.miami.edu