28 January, 2012

Still seeing green

Time for another quick algae update. The local media has been scattered with articles over the past several days and as of Wednesday morning, the Barwon has been closed upstream of Moorabool Street to below Baum's Weir according to information from the Corangamite Catchment Management Authority who are responsible for monitoring the river's health.
Lake Connewarre is also closed but the river at Barwon Heads is not, despite toxin levels being high there too. Certainly there was no visible indication of the algae at Barwon Heads a week ago, however the problem with the toxins produced by blue green algae is that, unlike the algae itself, they are colourless and odourless, meaning that it is not possible to gauge river health with the naked eye. In addition, the toxins can hang around longer than the algae, meaning that water quality can be unsafe even once the bloom is gone, as various authorities have been at pains to point out.
On Wednesday I thought I'd have a look at Lake Connewarre and see if the bloom was as spectacular there as the one upriver, however I was to be disappointed on this occasion. Water levels were clearly lower than over winter and I could certainly see a distinctly green tinge to areas of the lake, but nothing like the luminescent shades at Queen's Park.
Blue green algae at Lake Connewarre
As of Friday morning, the river was still closed to water activities - although for some reason this doesn't seem to include rowers as it seemed that every school for a good many miles around had at least one crew on the water. Maybe they are immune to such toxins or perhaps too tough to care!
 In my own quest to maintain some grit, I went for a run to Queen's Park and back and snuck a quick glance at the river on my way past. Certainly it was still more green than brown in many parts, but there didn't seem to be quite the same crust of algae covering the surface of the water near the lilies as there was earlier in the week.
Women's coxed fours
Nor it seems is a bit of green muck a hindrance to a two day rowing carnival on the river. The competitors, officials and supporters assembled bright and early Saturday morning and with appropriate warnings about the action to be taken in case of contact with river water proceedings got under way as they have done on the Barwon for over 140 years. A previous post here has looked at the history of rowing on the Barwon.
Geelong Grammar eight

Corio Bay Rowing Club double scull
And so the events continued seemingly with no ill effects either for the rowers or the family of ducks paddling in the shallows. Meanwhile, we sat on the bank on a sunny afternoon and took in the view, high and dry and safe from the algae.
By contrast, the weather forecast for the next couple of days is not quite so benign and there may well be some rain to flush the system clean. Help may also be at hand in the form of a serendipitous release of 40 million litres of water into the Moorabool from the reserves at Lal Lal. Whilst it won't be much help upstream of Fyansford, it may help water quality downstream through Geelong.
This ten day release which began on the 23rd January is one of three for the summer designed to deliver "environmental" flows to the river, enhancing the benefits already derived from the good rainfall over the last year. It has also been timed to coincide with the release of 27 million litres of water per day into the river for use by Geelong over the summer months.
So hopefully with a little time and a bit more water, all should soon return to normal.

No comments:

Post a Comment