2 research outputs found
Influence of Hydrological Variables on Macrophytes in a Black Water River Ecosystem
This study assessed the influence of hydrological variables on
macrophytes in a Black Water River ecosystem of Enyong River in Itu and
Ibiono Local Government Areas of Akwa Ibom and Cross Rivers States,
Nigeria. Four vegetation plots were chosen and in each of the plots,
four belt transect were laid. In each transect, macrophyte were
systematically sampled in four 10 m
7 10 m quadrat at regular
intervals. Macrophytes were identified to species level and their
frequency and density determined. Water samples were obtained in each
quadrat where the macrophytes were sampled and analyzed for their
physicochemical properties using standardized methods. Altogether, 10
macrophyte species were encountered. Vossia cuspidata had the highest
density (100.00\ub18.00 st/ha) and frequency values (100 %).
Sacciolepis africana had the least density of 7.10\ub10.45 st/ha
while Ludwigia octovalvis , Persicaria senegalensis , and Sacciolepis
africana had the least frequency of 25 %, respectively. The pH of the
water was strongly acidic (5.54\ub10.03), electrical conductivity was
low (20.00\ub15.77 \u3bcs/cm), temperature (29.00\ub11.10
\ubaC), Dissolved Oxygen (DO) (9.20\ub10.12 mg/l) and turbidity
(7.10\ub10.06 NTU) values were high while Biological Oxygen Demand
(BOD) (2.00\ub10.29 mg/l) Total Dissolved Solids (TDS)
(10.00\ub10.29 mg/l) and Total Suspended Solids (TSS) were low
(5.00\ub11.15 mg/l). Water Nutrients followed this decreasing order;
chloride (3.55\ub10.02 mg/l) > nitrate (2.45\ub10.03 mg/l) >
sulphate (2.02\ub10.06 mg/l) > phosphate (0.08\ub10.01 mg/l) and
sulphide (0.03\ub10.02 mg/l). Heavy metals also followed this
descending order; Pb (0.50\ub10.03 mg/l) > Zn (0.07\ub10.02
mg/l) > Cu (0.03\ub10.02 mg/l). Canonical Correspondence Analysis
delineated 11 hydrological variables (temperature, pH, sulphate,
turbidity, phosphate, BOD, nitrate, DO, TDS, sulphide and TSS) which
exerted great influence on macrophyte distribution. V. cuspidata had
affinity to pH and temperature, Sacciolepis africana had affinity to
turbidity and BOD, Ludwigia octovalvis and Nymphaea lotus had
affinity to sulphate and chloride, respectively, while Ipomoea aquatica
and Alternanthera sessils had affinity to phosphate. On the other
hand, Persicaria senegalensis, Salvinia molesta , Azolla pinnata and
Ceratophyllum demersum had affinities to sulphide, DO, TSS and TDS,
respectively. Since hydrological variables regulate macrophyte
diversity and distribution, this study calls for consistent, monitoring
and management of this ecosystem against future environmental changes