Diatom communities in the riparian systems associated with Lagos Lagoon, Nigeria I. Seasonal and anthropogenic patterns in Majidun Creek
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Date
2016
Authors
Adesalu, T. A.
Kunrunmi, O. A.
Journal Title
Journal ISSN
Volume Title
Publisher
Schweizerbart and Borntraeger science publishers
Abstract
In this report, we describe the investigation of water samples from Majidun Creek, a
riparian system emptying into Lagos Lagoon, over a period of twelve months (February 2010–
January 2011). Samples were obtained using a 55 μm plankton net towed at low speed for
10mins. Various physico-chemical parameters were monitored; surface water temperature,
PO4-P, transparency, NO3-N, SO4
2- and silicate concentrations. All measured chemical parameters
were lower in the rainy season while surface water pH ranged from acidic to alkaline
(6.2–8.4), chlorophyll ‘a’ showed its highest value in the dry season. There was a remarkable
change in seasonal salinity values while conductivity values ranged between 0.01 and
13.15 (mS/cm) in raining and dry seasons, respectively. Fifteen different orders of diatoms
were recorded. The Naviculales dominated the diatom spectrum followed by Cymbellales,
Fragillariales, Thalassiophysales, Nitzschiales and Eunotiales. Changes in diatom communities
appear to be driven by two factors. The first, and dominant factor, is seasonality based on differences
between the rainy and dry seasons which is correlating with peak biodiversity and peak
biomass in diatom community structures. Anthropogenic impacts appear to be the second force
influencing diatom community structure with areas of high population density, showing alterations
in community composition when compared to regions with less human activity. Since
most of the monographs used by Nigerian algologists are not indigenous, this paper may assist
in solving a part of the diatom identification problems.
Description
Keywords
diatoms , SEM , creek , plankton
Citation
Adesalu, T. A. and Kunrunmi, O. A. (2016). Diatom communities in the riparian systems associated with Lagos Lagoon, Nigeria I. Seasonal and anthropogenic patterns in Majidun Creek. Algological Studies 150: 39–52