Preliminary observations on the preservation of organic-walled algae in shallow, freshwater lakes from south–central Missouri, USA

Abstract

Algal palynomorphs can provide key ecological information about aquatic environments, yet the preservation potential for most varieties of algae is poorly understood. Cores from Pine Forest and Bray Area lakes, two man-made lakes in the Rolla area of south–central Missouri, USA, provided an opportunity to relate the algal palynomorphs in the top 9 cm of sediments to the processes that lead to preservation. By comparing algal palynomorphs in the sediments to the algal crop in the water, this study seeks to assess the effects of taphonomy on the assemblage in a palynological sample. The lakes were ecologically monitored four times in one year (late fall, spring, summer, winter) to determine the algal crop, and surficial sediment was sampled in Pine Forest Lake once in early winter. The annual average abundance of algae in the lake water was compared with sediment data, and statistical techniques (Kruskal–Wallis test, Mann–Whitney U-test and Pielou's Equitability index) were used to determine ecological stability in the sediments. While Sphaerocystis and Ceratium hirundinella did not apparently preserve well, moderate to high preservation potential was determined for Staurastrum and Botryococcus. In addition, Pediastrum simplex var. pseudoglabrum, P. integrum and P. boryanum var. pseudoglabrum were well preserved in the sediments. This preliminary study shows that a highly abundant algal species in the water may not be well preserved in the sediment. Therefore, higher resolution studies are needed to further explore the preservation potential of algae in lake sediments.

Keywords:

• freshwater
• algae
• shallow lakes
• preservation potential
• south-central Missouri

Acknowledgements

We thank the following researchers for their invaluable assistance during this study: Jack Jones, University of Missouri–Columbia (feedback and direction about nutrients); Dan Obrecht and the University of Missouri–Columbia's Fisheries and Wildlife laboratory (analytical work on nutrients); Cheryl Seeger and Pat Mulvany, Missouri Geological Survey (aerial photographic records); Dev Niyogi and Jeffrey Cawlfield, Missouri University of Science and Technology (ecological monitoring and statistical modeling); Francine McCarthy, Brock University (identification of dinoflagellate cysts); and Jiri Komarek, University of South Bohemia (identification of species of Pediastrum). Detailed feedback from two anonymous reviewers greatly improved this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors

Notes

1. The underlying research materials for this article can be accessed in the lead author's forthcoming dissertation entitled “Multi-Proxy Palynofloral Reconstructions: Case Studies from Southeast Missouri and the Côte d'Ivoire - Ghana Transform Margin” from the Missouri University of Science and Technology.

Additional information

Funding

Funding was provided in part by the National Science Foundation [grant number EAR-0719838] to Oboh-Ikuenobe.

Notes on contributors

Robert D. Haselwander

ROBERT HASELWANDER is currently a doctoral candidate at Missouri University of Science and Technology pursuing research in palynology and sedimentology. His studies in the Holocene include searching for a continuous lake record of the Pleistocene–Anthropocene from the Ozark Plateau and studying anthropogenic-mediated changes in man-made impoundments in Missouri. In addition to this work, he is also examining the Maastrichtian–Paleocene palynological records of West Africa.

Francisca E. Oboh-Ikuenobe

FRANCISCA E. OBOH-IKUENOBE is Professor and Interim Chair of the Department of Geosciences and Geological and Petroleum Engineering at Missouri University of Science and Technology. Her research interests in palynology and sedimentology spans the Phanerozoic of the USA, Western Australia, Africa and northern South America. She received BSc and MSc degrees in Geology from the University of Ife (now Obafemi Awolowo University), Nigeria and a PhD from the University of Cambridge, UK. Franca is a Fellow of the Geological Society of America, Past President of AASP – The Palynological Society and former Director of the Association for Women Geoscientists Foundation.