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

Table 4

Spatial variation of water physicochemical parameters in Aiba and Onikan lotic systems (May 2013–March 2014).

Parameter	Upper reaches	Lower reaches	Mann-Whitney test
			value	value
Aiba stream
Water temperature (°C)	25.6 ± 1.3	27.3 ± 1.6	7	0.0927
Water depth (m)	0.8 ± 0.1	1.3 ± 0.4	2.5	0.0163
Secchi depth (m)	0.26 ± 0.14	0.56 ± 0.18	3	0.0202
Channel width (m)	14.3 ± 2.3	15.0 ± 3.3	15	0.6889
Flow velocity (m/s)	0.022 ± 0.022	0.009 ± 0.009	11	0.298
Discharge (m^3/s)	0.252 ± 0.116	0.473 ± 0.635	10	0.2298
TS (mg/L)	269 ± 251	114 ± 26	3	0.0202
TSS (mg/L)	200 ± 223	53±19	2	0.0131
TDS (mg/L)	69 ± 36	61 ± 28	16.5	0.8728
pH	7.27 ± 0.76	7.20 ± 0.29	12	0.3785
Electrical conductivity (S/cm)	126.0 ± 32.4	117.3 ± 29.3	13.5	0.5218
Total alkalinity (mgCaCO3/L)	36.1 ± 16.0	36.6 ± 14.5	17	0.9362
(mg/L)	0.65 ± 0.77	0.86 ± 0.55	10.5	0.2623
(mg/L)	0.57 ± 0.41	0.57 ± 0.45	16.5	0.8728
Dissolved oxygen (mg/L)	2.6 ± 1.4	5.9 ± 1.6	2	0.0131
Onikan stream
Water temperature (°C)	25.9 ± 1.5	26.7 ± 1.5	10.5	0.2623
Water depth (m)	0.32 ± 0.09	0.98 ± 0.32	2.5	0.0163
Secchi depth (m)	0.24 ± 0.07	0.54 ± 0.18	3.5	0.0250
Channel width (m)	1.9 ± 0.7	4.1 ± 0.9	1	0.0082
Flow velocity (m/s)	0.187 ± 0.144	0.014 ± 0.019	10	0.2298
Discharge (m^3/s)	0.146 ± 0.136	0.065 ± 0.117	15.5	0.7488
TS (mg/L)	184 ± 20	115 ± 40	8	0.1282
TSS (mg/L)	106 ± 31	55 ± 37	11	0.298
TDS (mg/L)	78 ± 39	60 ± 36	15	0.6889
pH	7.38 ± 0.63	6.97 ± 0.13	17.5	1
Electrical conductivity (S/cm)	194.0 ± 62.3	159.5 ± 82.3	15.5	0.7488
Total alkalinity (mgCaCO3/L)	45.5 ± 23.5	33.6 ± 13.2	17	0.9362
(mg/L)	0.43 ± 0.39	0.68 ± 0.38	10	0.2298
(mg/L)	0.36 ± 0.28	0.64 ± 0.49	9	0.1735
Dissolved oxygen (mg/L)	5.8 ± 1.4	6.0 ± 1.1	13	0.4712

= 12, critical value of = 5 at .