Translator Disclaimer
1 March 2019 Spatiotemporal Variability in Autotrophic and Heterotrophic Microbial Plankton Abundances in a Subtropical Estuary (Galveston Bay, Texas)
Alicia K. Williams, Antonietta Quigg
Author Affiliations +

Williams, A.K. and Quigg, A., 2019. Spatiotemporal variability in autotrophic and heterotrophic microbial plankton abundances in a subtropical estuary (Galveston Bay, Texas). Journal of Coastal Research, 35(2), 434–444. Coconut Creek (Florida), ISSN 0749-0208.

The subtropical estuary Galveston Bay (Texas) is influenced by frequent riverine pulses from two important rivers in its northern sector and by ocean tides from the Gulf of Mexico in its southern sector. This study examined combinations of abiotic and biotic factors that synergistically influence spatiotemporal variability of autotrophic and heterotrophic microbial plankton abundances (0.2–20 µm). Potential nutrient limitation observed in situ was supported by in vitro enrichment bioassays. Shifts in the relative in situ abundance of autotrophs and heterotrophs, stained with SYBR Green I and enumerated on a flow cytometer, were significantly related to temperature, total nitrogen, dissolved inorganic nitrogen-to-phosphorus ratios, and total organic carbon concentrations along estuarine gradients. Observations reveal a pattern of serial colimitation of the microbial plankton community. Among the variables tested, nitrogen became the principal limiting factor for growth if phosphorous was available and temperatures were warm. In vitro nutrient enrichment bioassays performed with inorganic nitrogen (as nitrate) and Pi revealed variations in the responses between autotrophic and heterotrophic microbes under nutrient-limiting conditions, particularly during co-occurring phytoplankton blooms. The measured dynamics in planktonic relationships will have important impacts on understanding estuarine nutrient processing.

©Coastal Education and Research Foundation, Inc. 2019
Alicia K. Williams and Antonietta Quigg "Spatiotemporal Variability in Autotrophic and Heterotrophic Microbial Plankton Abundances in a Subtropical Estuary (Galveston Bay, Texas)," Journal of Coastal Research 35(2), 434-444, (1 March 2019).
Received: 4 January 2018; Accepted: 9 July 2018; Published: 1 March 2019

Estuarine microbial ecology
flow cytometry
microbial competition
microbial nutrient limitation
Get copyright permission
Back to Top