Table 2.

Descriptive statistics for environmental variables used to assess the occurrence of infected snails at Ethiopian Rift Valley lakes (TSS = total suspended solids, NTU = nephelometric turbidity unit, SD = standard deviation).

Environmental Variable	Unit	Mean	SD	Minimum	Maximum
pH	-	9	1	6	10
Turbidity	NTU	20	31	2	247
Dissolved oxygen	mg/L	5	3	0.5	17
Chlorophyll-a	µg/L	25	13	11	76
Electrical conductivity	µs/cm	564	243	71	940
BOD5	mg/L	26	40	0.3	184
TSS	mg/L	43	31	5.2	136
Total hardness	mg/L	68	22	24	120
Calcium ion	mg/L	49	18	16	100
Magnesium ion	mg/L	19	8	0	36
Chloride ion	mg/L	29	9	11	48
Water depth	m	0.6	0.3	0.2	2
Water transparency	m	0.3	0.1	0	0.6
Water temperature	°C	24	3	19	30
Ambient temperature	°C	26	2	20	31
Canopy cover	%	16	21	0	100