Currently there is a large algal bloom in the Gippsland Lakes – a natural event according to some. A long article in the Bairnsdale Advertiser (4.5) looked at the various causes of the bloom. In a letter to the editor I noted that the blooms are being caused by a number of factors including the increased salinity of the Lakes due to a deepened entrance and the run-off of nutrients from farms into the river systems. In particular East Gippsland Water’s discharge from the Paynesville sewage plant into Forge Creek and then Newlands Arm was mentioned.
As to whether the blooms are naturally occurring we have witnessed a number since the early 1980s but the earth has been gradually warming all that time. It seems more likely that they are an indication that something is clearly wrong. The USA EPA noted that “warmer temperatures prevent water from mixing, allowing algae to grow thicker and faster. Warmer water is easier for small organisms to move through and allows algae to float to the surface faster. Algal blooms absorb sunlight, making water even warmer and promoting more blooms.”
In a blog on a bloom in the Gippsland Lakes in the summer of 2016 I wrote that they “are a direct and immediate threat to the [local] economy and are directly related to climate change and other changes to the Lakes system.” And that they “can flourish with a number of factors one of which is warmer waters, which in turn is a direct response to our warming planet. The shallow waters of the Lakes are warming faster than our oceans which in turn are already warming faster than our land.”
A scientific audit is needed. It should be continuing, include literature searches, and monitor a wide variety of data including salinity, nutrients, heavy metals and temperatures. On the bigger question of global warming and the Gippsland Lakes, the future does not look promising. By the time the climate emergency is adopted across the country and the earth, much of the damage inflicted on the lakes system may be irreparable. But that is not a cause for inaction and we must work hard to save what we can.