TABLE 1.

Geographical and limnological characteristics of the localities

Water body sampled	Geographic position			Altitude above sea level (m)	Analytical variable
	County	Latitude	Longitude		pH	Conductivity (mS/m)	Phosphorus concn (μg/liter)	Nitrogen concn (μg/liter)	Total dissolved carbon (mg/liter)	Chlorine concn (mg/liter)
Lake Steinfjordenb	Buskerud	60°04′N	10°20′E	63	7.6	10.3	7	250	5.1	5.1
Lake Gjersjøena	Akershus	59°40′N	10°53′E	40	7.6	19.7	6	1,500	6.5	18.5
Lake Stensrudtjerneta	Oslo	59°48′N	10°55′E	133	7.2	16.0	12	435	9.5	26.4
Lake Langena	Akershus	59°45′N	10°58′E	126	6.9	5.86	17	420	8.7	6.5
Lake Østensjøvanneta	Oslo	59°54′N	10°49′E	107	7.3	14.0	124	1,180	8.9	9.4
Lake Holstadvatneta	Oslo	59°40′N	10°53′E	91	7.9	22.9	135	1,200	10.2	19.0
Lake Årungena	Akershus	59°41′N	10°45′E	34	7.6	26.8	69	3,940	11.3	25.6
Lake Fløtjønnac	Møre & Romsdal	63°20′N	8°04′E	1	—d	—	—	—	—	—

^aDate of sampling: 3 September 1998 (surface water). 

^bDate of sampling: 21 September 1998 (surface water). 

^cLake influenced by marine water. Date of sampling: 29 May 1996 (surface water). 

^d—, not determined.