IN response to a fish kill at Lake Bullen Merri in Victoria last month, the Victorian Fisheries Authority (VFA) asked Austral Research and Consulting to help investigate the cause. Now they have the results.
The VFA tested water quality, sent fish to the laboratory and reviewed historical water quality data at the lake.
While the results are not conclusive, the most likely cause of the fish kill is high pH (up to 9.3), which is at the extreme end of the spectrum for this lake.
High pH combined with other environmental factors such as drops in temperature and the release of ammonia from dying algae blooms can be very stressful to fish.
As algae strip oxygen out of the water at night, the VFA says it can’t discount low oxygen levels as a contributing factor.
There is a long history of fish kills in Bullen Merri associated with poor water quality due to algal blooms, however we haven’t seen a significant fish kill in this lake for more than decade.
There have been no more fish kills since April, so it’s safe to return to fishing Bullen Merri. Get out there this weekend and reel in some trophy trout and Chinook salmon!
