Phytoplankton distributions and species composition across the Texas-Louisiana continental shelf during two flow regimes of the Mississippi River /

1993, which was a record flow year. Water samples for

Bibliographic Details
Main Author: Bontempi, Paula Susan, 1970-
Format: Thesis eBook
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1995.
Subjects:
Online Access:Link to OAKTrust copy
Description
Summary:1993, which was a record flow year. Water samples for
and May 1993, as part of a phytoplankton diversity study
and others were predominant in both years. On the middle
as dinoflagenates, microflagellates, and coccolithophorids
became more dominant. The outer shelf upper water column was
benthos supported the phytoplankton community on the middle
concentrations in May 1993 were approximately double those in
costatum (Grevifle) Grunow, which is found in a range of
cross-shelf transacts from 90.5' to 94.0'W longitude.
CTD, preserved in 1% glutaraldehyde, and analyzed using the
decreased more moving from the middle to the outer shelf.
differences were found in May 1993 due to the record river
discharge. In 1992 and 1993, the inner shelf was diatom
distribution data were assessed in relation to the
distributions from 1992 , which was an average flow year for
dominant than on the middle shelf. The diatom population
dominated, and was characterized by the highest nutrient and
dramatic shift in dominant diatom species to Skeletonema
Effects of a warm core Loop Current eddy were evident on the
found to be oligotrophic, so smaller or more motile cers such
funded by the Office of Naval Research. Phytoplankton
hydrography and physical processes on the shelf, which were
hydrography and physical processes were found on the inner,
Lower concentrations of phytoplankton were present on the
lowest safety values. River discharge and associated
maximum from Niskin bottles attached to a Sea-Bird SBE911plus
May 1992. The increased river discharge in 1993 caused a
may provide a means of supporting the phytoplankton
microflagellates, and coccolithophorids were even more
middle shelf than the inner shelf during both years. The
middle, and outer shelf during both flow regimes. Some
nutrient-poor as well during both years, and dinoflageuates,
nutrients were focused by the localized downcoast flow
of the shelf to the western part in May 1992. The opposite
outer shelf area. Upwelling processes shallower than 100 m
over the Texas-Louisiana continental shelf during May 1992
overall phytoplankton abundance in May 1993.
Phytoplankton abundance and species composition were examined
phytoplankton determinations were examined at 22 locations on
population at the chlorophyll maximum on the outer shelf.
possibility of benthic regeneration of nutrients and
predominant on the inner shelf area during the month of May.
regime was present in May 1993. Inner shelf nutrient
resuspension into the upper water column. This flux from the
salinities, temperatures, and depths. Chain-forming diatom
Samples were collected at the surface and the chlorophyll
shelf, the presence of tychopelagic diatoms reflected the
shelf, where a near-bottom chlorophyll maximum was found.
studied as part of the Texas-Louisiana Shelf Circulation and
The location of the increased volume of river water across
the Mississippi River, were compared with observations from
the shelf in May 1993 was identified based on the increase in
Transport Processes Study (LATEX A). Phytoplankton group
Unique phytoplankton distributions and regionspecific
upper 30-70 m of the water column on the middle shelf were
Uterm6hl method and the inverted-microscope technique.
Water column stability decreased moving from the eastern part
Item Description:"Major subject: Oceanography".
Vita.
Physical Description:xiii, 261 leaves : illustrations, maps ; 28 cm.
Also available online.
Issued also on microfiche from Lange Micrographics.
Bibliography:Includes bibliographical references.