Date of Award

Spring 5-2013

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)


Marine Science

Committee Chair

Donald G. Redalje

Committee Chair Department

Marine Science

Committee Member 2

Stephan D. Howden

Committee Member 2 Department

Marine Science

Committee Member 3

Kjell Gundersen

Committee Member 3 Department

Marine Science


Potential primary production was measured for six consecutive months (July 2010 to December 201 0) at selected stations along the shoreline of the Bay of Saint Louis (BSL) estuary. Monthly surface and a series of subsurface (0.5 m) samples were taken to observe the temporal (monthly and short-term) and spatial variability in production relative to environmental variables that potentially could influence phytoplankton photosynthesis. Daily areal primary production, PP was modeled using photosynthesis-irradiance (P-E) parameters in conjunction with in situ irradiance measurements and biomass data collected during sampling. Although spatial variability was not observed, PP varied seasonally and ranged from 1.90 g C m-2 d-1 in July to 0.06 g C m-2 d-1 in December. Short-term variability also was observed. Production ranged from 0.25 to 0.84 g C m-2 d-1 over the course of a week and within-day values ranged from 0.36 to 0. 72 g C m-2 d-1 with peak production occurring at midday. Temporal variability was attributed primarily to changes in temperature (seasonal), river discharge (week-long), and incident irradiance (diurnal). Annual production for the BSL estuary was estimated at 197.3 g C m-2 d-1 and is comparable to other temperate, mesotrophic estuaries. The results from this study provide the first modeled estimates of primary production within the BSL system and will facilitate ecological research and monitoring efforts within this locally important estuary.