Water Physicochemistry and Zooplankton Fauna of Aiba Reservoir Headwater Streams, Iwo, Nigeria

Table 3

Descriptive statistics and seasonal variation of water physicochemical parameters in Onikan lotic system (May 2013–March 2014).

Parameter	Descriptive statistics			Seasonal variation		Mann-Whitney test
	Minimum	Maximum	Mean ± S.D.	Rainy season	Dry season	value	value
Water temperature (°C)	24.8	29.0	26.4 ± 1.5	25.3 ± 0.6	27.6 ± 1.3	6.5	0.0784
Water depth (m)	0.2	1.2	0.7 ± 0.4	0.8 ± 0.5	0.6 ± 0.4	15	0.6892
Secchi depth (m)	0.20	0.70	0.40 ± 0.21	0.36 ± 0.21	0.46 ± 0.22	16.5	0.8729
Channel width (m)	1.0	5.0	3.1 ± 1.4	3.6 ± 1.7	2.7 ± 1.0	15.5	0.7488
Flow velocity (m/s)	0	0.33	0.092 ± 0.129	0.113 ± 0.141	0.067 ± 0.124	8	0.1282
Discharge (m^3/s)	0	0.300	0.102 ± 0.126	0.113 ± 0.131	0.089 ± 0.133	9.5	0.2002
TS (mg/L)	62	198	146 ± 47	146 ± 36	147 ± 63	17	0.9362
TSS (mg/L)	12	130	78 ± 42	99 ± 23	53 ± 48	5.5	0.0547
TDS (mg/L)	34	144	68 ± 37	47 ± 18	94 ± 39	9	0.1735
pH	6.70	8.00	7.16 ± 0.46	7.17 ± 0.48	7.14 ± 0.49	14.5	0.6312
Electrical conductivity (S/cm)	85.0	300.0	175.2 ± 72.6	127.4 ± 67.4	190.0 ± 79.5	10	0.2298
Total alkalinity (mgCaCO3/L)	14	82	39.0 ± 18.6	48.7 ± 17.8	27.3 ± 12.4	4.5	0.0374
(mg/L)	0	0.98	0.56 ± 0.39	0.50 ± 0.41	0.64 ± 0.39	18	0.9362
(mg/L)	0	1.4	0.51 ± 0.42	0.42 ± 0.52	0.63 ± 0.27	13	0.4712
Dissolved oxygen (mg/L)	4.5	7.8	5.9 ± 1.2	5.1 ± 0.6	6.8 ± 1.1	8.5	0.1495

= 12, critical value of = 5 at < 0.05.