Probe into flea invasion
The water in Lake Wanaka is a wintry 10deg, but debate over a suspected link between an algal ’’lake snot’’ and an introduced North American water flea is heating up.
Otago Regional Council lake studies commence next week and if the link between the algae (Cyclotella bodanica) and the flea (daphnia pulex) is confirmed, the regional council, Guardians of Lake Wanaka and the Otago Fish and Game Council expect a national biosecurity response.
Guardians chairman Dr Don Robertson is also calling for greater investment from councils and businesses in water catchment and lake snot research. Otago Regional Coun- cil manager of resource science Dean Olsen said the Ministry of Primary Industries had been advised.
‘‘They have acknowledged that . . we will do this DNA work to see if it is an introduced species or not. They are the lead authority dealing with incursions of non-native species. Once we get these results back . . if it is an introduced species, we expect the response will change quite markedly,’’ Olsen said.
However, it could be four to six months before results are known, according to a update from Dr Gavin Palmer, the regional council’s director of engineering, hazards and science.
In the ‘‘Where to from here’’ section of his report, Palmer says the algae was spreading through the Southern Lakes and had economic implications for water supplies, recreation and tourism.
‘‘Lake snow also raises questions around the potential roles of biological invasions and environmental change. The possibility that Cyclotella bodanica is an invasive species poses significant biosecurity implications to Otago and elsewhere across New Zealand,’’ Palmer said.
Anglers began reporting algae bloom in Lake Wanaka about 2004. Soon after, it was confirmed in Lake Dunstan. Lake Wakatipu had its first confirmed case in May and a similar slime has now been reported in Lake Hawea, although that has not been confirmed by analysis.
Guardians of Lake Wanaka chairman Don Robertson wants a Lake Wanaka management plan.