GEORGE NEWS - A team of experts is visiting Island Lake this week for investigations and deliberations about the blue-green algal growth that had required closure of the lake for recreational activities from 24 March to 15 June.
Sandra Taljaard, SANParks Wilderness Park manager, said the visit is not only in response to this year's occurrence of the algal but also similar occurrences in previous years.
The team includes limnologists from the University of the Free State (UFS), specialist scientists from SANParks and operational staff.
"They will try to get a better understanding of the re-occurrence and management of this phenomenon. During the week, there will also be interaction with interested and affected stakeholders," said Taljaard.
She said their conclusions should be available from next week.
When the algal were first spotted, an expert in the specialist field of freshwater occurrences at the UFS was approached. He indicated that it was likely a toxin-producing species that could pose a health risk to humans. Throughout the past few months, SANParks sought ongoing consultation and guidance from experts.
Toxins
"Weekly samples were taken at eight dedicated sites and were analysed for the elements nitrite, nitrate, orthophosphate, ammonium and total cyanobac-teria count.
"The two important cyanobac-teria genera that were identified were Anabaena and Microcystis. The Anabaena algal produce anatoxin, which is a neurotoxin, and the Microcystis produce a hepatic toxin that affects the liver," said Taljaard.
Through ongoing sampling, the severity of the toxins was analysed according to the national water quality standards. The lake was reopened only after the water results were within the acceptable limits of national water quality guidelines.
"It is important to also note that the most dangerous time of a cyanobacteria bloom is when it starts decomposing, thus the extended period of closure of the lake. During this time it releases large concentrations of external toxin," said Taljaard.
She said that observations and patrols for bird, fish and animal mortalities revealed no significant numbers.
'We bring you the latest George, Garden Route news'
