Vasse Estuary – toxic algal bloom reports
Released 02 Jun 2017
Although no fish deaths have been observed, the Department is closely monitoring the waterways and investigating possible causes for the elevated algae levels.
Karlodinium species occur naturally in low levels in ecosystems worldwide. In some cases, the species can form an intense bloom, which as it dies and breaks down, releases fish-killing toxins into the water.
Blooms of Karlodinium species have occurred annually in the Vasse estuary since 2013, however the concentrations have been much lower than detected this week.
Dr Kath Lynch from the Department of Water said Karlodinium species prefer stratified conditions (where the water forms ‘layers’) and cooler water temperatures that often occur after first rains at the end of autumn.
Monitoring of the Vasse estuary, however, showed no stratified conditions, with the salinity of the water close to that of seawater.
“At this stage we are unsure why the Karlodinium bloom has intensified” said Dr Lynch.
“We are monitoring the situation and are currently working to determine what environmental conditions might have contributed to the bloom”.
As a management action Water Corporation has opened the fish gates on the Vasse surge barrier to allow fish to move through the gates and dilute the bloom.
Neighbours to the Vasse estuary channel have also been notified.
The Department of Health advises against recreating in waterways during a fish kill or algal bloom event.
The departments greatly appreciate the support and assistance of the community and encourage people to report any algal blooms to ALGALWATCH on 08 6250 8064 and report any fish deaths to the Department of Fisheries FishWatch on 1800 815 507.
Contact: Sarah Lau
Phone: (08) 6364 7549 / 0414 507 739