COMPARATIVE PLANKTON SURVEY AND PHYSICOCHEMICAL ASSESSMENT OF TWO PONDS IN KANO METROPOLIS, NIGERIA

Abstract

Monthly charges in plankton periodicity levels, temperature, pH, turbidity and heavy
metals were studied in two ponds in Kano metropolis for a period of 12 months. Physico-chemical
parameter studied has shown that temperature, pH and turbidity ranged between 14.2-33.5˚C,
6.5-8.6 and 2.3-143 NTU respectively. Dissolved oxygen, biochemical oxygen demand, nitrate and
phosphate concentration were within the ranges of 3.3-7.9 mg/1, 1.1-6.4 mg/1, 1.26-12.2 and
1.11-9.60 mg/1 respectively. Plankton periodicity in the ponds shown two phases separated by
shift in nutrient concentration and temperature regimes. Significant difference occurred between
the wet and dry seasons values of temperature, pH, turbidity, nitrate, phosphate, phytoplankton
and zooplankton (p<0.01). However, no significant different was found between the seasons in
terms of BOD5 at p>0.05. Phytoplankton and zooplankton densities were found to correlate
positively with pH, BOD5 nitrate, phosphate and the heavy metals (p<0.01). Ten (10)
phytoplankton species were identified in the ponds dominated by Green algae (site A 50.00% and
site B 71.43%)and (7.14%) each for blue green algae, diatom and flagellate, while Eight
zooplankton species were identified dominated by rotifera 3 (29.47%) followed by protozoa 2
(18.03%), copepoda 1 (18.18%), and flagellates 1 (15.58%). While 22.35% was recorded for
nematoda. Double maxima occurred in terms of the total monthly density of phytoplankton
recorded from site B which were 8,653 and 7,126 orgs/l in April and February respectively.