Richmond fish kills
Severe flooding in Northern NSW has caused large fish kills throughout the region, caused by an influx of freshwater into the estuarine areas and low oxygen levels due to a break down of organic matter in the water. There were, “Lots of flathead, bream, eels, prawns, mullet, stingrays, we saw dead sharks, any fish you could imagine was just floating on the surface, belly up” (source).
New South Wales Fisheries have declared a three-month moratorium on all fishing in the Richmond River. The worst affected area was Ballina Quays near the Burns Point ferry. An estimated 33 tonnes of fish were removed by Council from this site. They’re now waiting for the acid plumes to start emanating.
All photos: NSW DPI
January 24th, 2008 at 10:19 am
Nice that the scientist is saying that good will come of it RE: Watching the recolonisation that’s something positive.
I don’t get it Dr. Tom how would rotting veg. reduce the o2 levels?
January 24th, 2008 at 12:14 pm
Increased volumes of particulate and dissolved organic matter (leaves, detritus etc.) result in increased biological activity (breakdown of this matter by organisms like bacteria). This uses up oxygen in the water column, causing the concentration to drop below the levels required for fish.
January 24th, 2008 at 8:08 pm
oh my god! what a catastrophe!