Littoral Vegetation and Physico- Chemical Characteristics of the Owabi  Lake in Ghana

Martin  Abed Arkoh; Alexander Kofi Anning

doi:10.4314/just.v41i2.1562

Mr. Martin Abed Arkoh Department of Theoretical and Applied Biology in the Faculty of Biosciences of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Prof. Alexander Kofi Anning Department of Theoretical and Applied Biology of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

DOI: https://doi.org/10.4314/just.v41i2.1562

Keywords: Littoral zone, Owabi lake, Physico-chemical parameters, Algae, Concentrations

Abstract

The littoral zone of water bodies serves as a habitat for plants and food source for fishes but could
be detrimental to the longevity of the lake if the growth and spread of plants are not controlled.
The littoral zones of the Owabi Lake is influenced by four river inlets that bring into the lake a
lot of sediments and other pollutants. Though these may be detrimental to the water body, they
also serve as nutrient source for the littoral vegetation. No work has been done previously on the
characteristics of the littoral vegetation of the Owabi Lake. The study thus assessed the general
floristic characteristics and the water quality of the Owabi Lake. The littoral perimeter of the lake
was divided into zones of 78 plots with 5 m X 5 m quadrats at 50 m intervals. The plant species
within each plot was assessed and enumerated. Additionally, the physico-chemical characteristics
of the littoral zone were determined using standard protocols. The study yielded a total of 30
plant species which belonged to 25 families. Acrocera zizanioides recorded the highest density of
91.21% but relative frequency of 16.08%. An algae, Lemna minor registered the highest relative
frequency of 16.35% but a relative cover of 0.013%. Acrocera zizanioides had the highest IVI of
107.30 with the herbs Chromlaena odorata and Lugwigia alata indicating an IVI of 0.27. Species
from the Asteraceae family had the lowest relative density (<1%). The lower portion of the lake
recorded higher plant cover with H and 1-D alpha diversity analysis indicating lower diversity
within the plants species (H<2.0), with the evenness being significantly different (p=0.03) between
the lower and upper portion of the lake. The physico-chemical characteristics of the lake indicated
higher concentrations at the lower portion, and that influenced the inward growth of plants into
the lake. The values obtained were within the WHO limits with only the light intensity being very
low at the upper portion due to shades from tree covers. The higher concentrations of nutrients
with adequate light intensity at the lower portion of the lake could account for the relative higher
density and IVI of plants at that part of the lake. The uncontrolled inward growth of plants at
the lower portion of the littoral zone of the Owabi lake could narrow its size with time and poses
danger to the sustainability of the water body.

Author Biographies

Mr. Martin Abed Arkoh, Department of Theoretical and Applied Biology in the Faculty of Biosciences of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

Martin Abed Arkoh is a Lecturer in the Department of Theoretical and Applied Biology in the Faculty of Biosciences of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. He holds a BSc in Zoology/Botany from the University of Cape Coast and MPhil Biology from KNUST. His research areas are into manipulation of plants against malaria parasite vectors, environmental biology and wetland ecology. His main research now is to study all components of the Owabi wetland and how these can be manipulated for better sustainability and conservation.

Prof. Alexander Kofi Anning, Department of Theoretical and Applied Biology of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

Alexander K. ANNING is an associate professor in the Department of Theoretical and Applied Biology of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. He is into forest ecology, and obtained his BSc and MSc in Biology from the Biology Department of KNUST with his PhD from the Ohio University in Athens, USA. He has done extensive research into tropical forest ecosystems, and has made his research findings public by publishing in both local and international journals of repute