Interesting, but, apparently no worse than the bay after rain.
http://www.theage.com.au/victoria/w...est-beaches-for-swimming-20160106-gm0cj4.html, and which can be monitored at
http://yarraandbay.vic.gov.au/beach-report
There are well documented spikes in E. Colli after rain events flushing contaminants into major water courses, including the bay. While much of this is pet shit (hands up all those who thought picking it up was both unreasonable and bureaucratic in the extreme), but then, there is the number of septics along river (yes from those expensive houses) that significantly is dominant in the primary cause
http://www.theage.com.au/news/Natio...arra-is-so-sick/2005/01/21/1106110948142.html). Can be monitored at
http://yarraandbay.vic.gov.au/yarra-watch
In all not a great situation but unfortunately the reality in many environments when personal choice and a sense of entitlement but not responsibility, prevails. I regularly kayak on sections of the Yarra, and have done for over 35+ years. None the less., and perhaps surprisingly, it is actually in much better shape now than then (but still not good enough).
EPA and Melb H2O have a river health programme running to either get rid of all septics, or get them updated in performance and monitored throughout the Yarra corridor.
Paddle upstream to the agricultural areas and you will see even more undesirable inputs,
I don't mean to be unkind, but not sure exactly what your take home message, or rather, suggested action to address this is.
If you are genuinely concerned, time to put that energy into making a change (attention grabbing headlines generally achieve squat).
It's clear we are responsible. If that is the message, then call the spade a bloody shovel, if not, well, "Might be worth keeping your mouth closed", as you say.