The littoral Chironomidae (Diptera) of saline lakes in central British Columbia

Collections of chironomid larvae, pupae, and adults were taken from the 1-m depth zone of 15 lakes of varying salinities in central British Columbia. Thirty-four species were identified.The littoral chironomid fauna of the lake series is divided into predominant associations whose existence seems to depend on salinity and productivity levels. A Cricotopus abanus – Procladius bellus association prevails in the lowest salinities (40 to 80 μmho/cm (1 mho = 1 S) conductivity) while in conductivities between 400 and 2800 μmho/cm a Glyptotendipes barbipes – Einfeldia pagana association predominates. In the most saline lakes (conductivity 4100 to 12 000 μmho/cm) a Tanytarsus gracilentus – Cryptotendipes ariel association is characteristic.Using these three chironomid associations it is possible to divide the 15 lakes into three groups. Waters with conductivities from 40 to 80 μmho/cm have chemical characteristics and a chironomid fauna distinct from those of higher salinities. The 10 lakes showing increasing conductivity (400 to 2800 μmho/cm) have physical, chemical, and biotic characters related to high productivity. In the particular case of this saline lake series, lakes with salinities about 3‰ (conductivity above 4000 μmho/cm) have a reduced productivity and a chironomid fauna characteristic of high salinities.