I see from the Newcastle Herald that there has been another Myall Lakes' fish kill. It comes a week after the mysterious death of thousands of fish in the Port Stephens-Great Lakes marine park.
Commercial fisherman Neville Smith, estimated about half a tonne of dead fish was strewn along a kilometre of the shore.
Back in January in January 08 floods lead to major Richmond River fish kill I reported on Richmond River problems. There the key cause appeared to be low oxygen levels in the water. In this case, descriptions of the fish suggest a medical problem.