Primary productivity by phytoplankton : temporal, spatial and tidal variability in two North Carolina tidal creeks
- UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
- Virginia L. Johnson (Creator)
- Institution
- The University of North Carolina Wilmington (UNCW )
- Web Site: http://library.uncw.edu/
- Advisor
- Michael Mallin
Abstract: Tidal creeks along the Coastal Plain are subject to rapid increases in
urbanization and the associated pollution can have profound effects on
ecosystem processes. Temporal, spatial and tidal variability of one such
process, phytoplankton primary productivity, was examined in two tidal creeks in
southeastern North Carolina. Physical, chemical and biological data were used
to assess the factors regulating phytoplankton productivity and the magnitude
with which urbanization has affected ecosystem function within these systems.
Annual phytoplankton productivity in un-canopied high tide waters was
approximately 91 gC m-3 in Futch Creek and approximately 246 gC m-3 in
Hewletts Creek. Elevated primary productivity corresponded with the summer
chlorophyll a maxima in both creeks, but was significantly higher in the creek with
greater watershed development, Hewletts Creek, during summer months.
Spatial variability in primary productivity in Hewletts Creek indicated upper
oligohaline to mesohaline reaches were characteristically more productive during
summer months than lower euhaline creek areas. Although there were defined
temporal trends in phytoplankton productivity in the lesser developed Futch
Creek, spatial variability between creek reaches was not as pronounced.
Primary productivity was generally higher at low tide when compared to high tide
in both creeks. Decreased water column irradiance occurred periodically in the
upper reaches of both creeks, especially following meteorological events.
Nutrient concentrations in Hewletts Creek, especially ammonium and
orthophosphate, were generally higher than in Futch Creek and were elevated at upstream sites and seasonally during summer months. Regression analyses
indicated that 83% of the variability in phytoplankton primary production was
explained by variations in temperature and phytoplankton biomass. The data
suggest that the physical environmental forces of a dynamic tidal creek system
govern basic seasonal, spatial and tidal patterns, but sediment and nutrient
inputs from upland development could have a pronounced effect on the
magnitude of a key ecosystem process, phytoplankton primary productivity.
Comparative analysis indicates that volumetric phytoplankton productivity in local
tidal creeks was on par or greater than other larger North Carolina estuaries.
This suggests that tidal creeks should be valued as a coastal resource and
management efforts should be implemented to preserve and possibly restore
environmental integrity.
Primary productivity by phytoplankton : temporal, spatial and tidal variability in two North Carolina tidal creeks
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Additional Information
- Publication
- Thesis
- A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfillment of the Requirements for the Degree of Master of Science
- Language: English
- Date: 2009
- Keywords
- Freshwater ecology--North Carolina, Freshwater phytoplankton--North Carolina--Futch Creek, Freshwater phytoplankton--North Carolina--Hewletts Creek, Phytoplankton--North Carolina
- Subjects
- Freshwater phytoplankton -- North Carolina -- Futch Creek
- Freshwater phytoplankton -- North Carolina -- Hewletts Creek
- Freshwater ecology -- North Carolina
- Phytoplankton -- North Carolina