CIUGULEA, IONEL I.1, DEBRA A. WATERS2*, JOHN W. DAY, JR.3, and RUSSELL L. CHAPMAN2. 1Department of Botany and Microbiology, University of Bucharest, Romania; 2Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA; 3Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana, USA. - Phytoplankton of a Mississippi River watershed in coastal Louisiana.
In July and August 2001, phytoplankton samples were collected from a
coastal marsh south of New Orleans, Louisiana. This wetland area is
usually cut off from the Mississippi River by levees and other flood
control devices, but periodically the Caernarvon Diversion is opened
to allow fresh river water to flow into the marsh. As part of a larger
project, the present study seeks to determine the affect the periodic
input of freshwater has on phytoplankton dynamics in the Caernarvon
Diversion watershed. The first phase of the project—collecting and
identifying algae during the summer when the Caernarvon Diversion is
kept closed—has been completed. 168 species from 76 genera
representing 8 phyla were identified and digital images recorded.
Little or no previously published data on the taxonomy and ecology of
phytoplankton from this area are available. Sampling in spring 2002,
when the diversion is open, will allow comparative analysis of
phytoplankton composition and productivity. In a collaborative study,
the phytoplankton data will be combined with information on nutrients,
chlorophyll a, turbidity, salinity, etc. and used in a model to
demonstrate how the ecosystem is affected by the diversion. Also, a
database of digital images is available at
www.chapman.lsu.edu/digitalalgae. In addition to the taxonomic
identification data and images, the site will eventually include
physico-chemical and GIS data on the collection sites. Supported in
part by a grant from the Office of Sea Grant Development at LSU.
Key words: Mississippi River, phytoplankton