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The Use of Chlorophyll Fluorescence Lifetime to Assess Phytoplankton Physiology within a River-Dominated EnvironmentChlorophyll a fluorescence lifetime was measured for phytoplankton populations inhabiting the three physical zones surrounding the Mississippi River's terminus in the Gulf of Mexico. Observations of river discharge volume, nitrate + nitrite, silicate, phosphate, PAR (Photosynthetically Active Radiation) diffuse attenuation within the water column, salinity, temperature, SPM, and chl a concentration were used to characterize the distribution of chl fluorescence lifetime within a given region within restricted periods of time. 33 stations extending from the Mississippi River plume to the shelf break of the Louisiana coast were surveyed for analysis of chlorophyll fluorescence lifetime during two cruises conducted March 31 - April 6, 2000, and October 24 - November 1, 2000. At each station, two to three depths were chosen for fluorescence lifetime measurement to represent the vertical characteristics of the water column. Where possible, samples were taken from just below the surface and from just above and below the pycnocline. All samples collected were within the 1% light level of the water column (the euphotic zone). Upon collection, samples were transferred to amber Nalgene bottles and left in the dark for at least 15 minutes to reduce the effects of non-photochemical quenching and to insure that photosynthetic reaction centers were open. Before measurements within the phase fluorometer were begun, the instrument was allowed to warm up for no less than one hour.
Document ID
20040000683
Acquisition Source
Stennis Space Center
Document Type
Preprint (Draft being sent to journal)
Authors
Hall, Callie M.
(NASA Stennis Space Center Stennis Space Center, MS, United States)
Miller, Richard L.
(NASA Stennis Space Center Stennis Space Center, MS, United States)
Redalje, Donald G.
(University of Southern Mississippi Bay Saint Louis, MS, United States)
Fernandez, Salvador M.
(Ciencia, Inc. East Hartford, CT, United States)
Date Acquired
September 7, 2013
Publication Date
January 5, 2002
Subject Category
Life Sciences (General)
Report/Patent Number
SE-2002-03-00018-SSC
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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