yingina/Great Lake is located in the central plateau area of Tasmania, a region renowned for its high degree of aquatic faunal endemism. Populations of the threatened Shannon paragalaxias (Paragalaxias dissimilis) and Great Lake paragalaxias (Paragalaxias eleotroides) occur throughout the lake, and are closely associated with the lake’s benthic habitats.

yingina/Great Lake is a mainstay of Tasmania’s hydropower system, particularly during dry periods. Record low rainfall during spring 2015, and a significant fault in the Basslink undersea interconnector, led to increased reliance on the lake for power generation, with water levels falling to the lowest on recorded since the 1967 drought. Water management operating constraints were successfully implemented for the lake to reduce the potential threat to Paragalaxias populations, namely dewatering of rocky, littoral, non-embedded spawning habitat and dewatering of eggs. 

It was recognised that the use of artificial spawning habitat could also be a potential mitigation measure to reduce the impact of extreme event related habitat loss, however the feasibility and effectiveness of using artificial habitats was not known. A pilot study was implemented to test the suitability of a range of naturally occurring and manufactured spawning substrates, and the preliminary results of this research are discussed.