Arctic Char, Prehistoric Life in our Lakes

Gill net surveys of fish life in Loughs Dan,Tay and Glendalough upper lough, Co. Wicklow

The following glacial loughs in Co. Wicklow were surveyed by standard multimesh monofilament benthic and pelagic gill nets in June 2005; Glendalough upper, Lough Dan and Lough Tay.
This report provides information on catch per unit effort and depth distribution of the fish community in the three loughs during the period of sampling.
The surveys form a baseline data set for all three loughs against which any future changes can be referenced.
The fish communities in all of the three loughs can be described as simple (i.e., consisting of only a few species). Native brown trout were present in all loughs sampled. Non-native minnow were recorded in both Loughs Dan and Glendalough upper. The brown trout were predominantly caught in the littoral or shallower strata of the loughs surveyed.
No Arctic char were recorded in any of three loughs. Despite historical records for the three loughs and a relatively recent record for Lough Dan, the combination of data indicates that Arctic char are now extinct in Lough Dan, Tay and Glendalough.
The loughs appeared to be unaffected by organic pollution and although minnow were discovered it is not thought that their presence would be inimical to Arctic char survival. Water temperatures were also favourable for this cold water species during the period of sampling.