No-fishing zones implemented to protect the Moreton Bay ecosystem have proven their worth in light of last year's flooding however the coral reefs and seagrass habitats are still at risk.

This is according to ongoing research by scientists at Griffith University's Australian Rivers Institute.

In partnership with the Department of Environment and Resource Management, flood monitoring work has revealed that substantial bleaching of the coral occurred but that it has since undergone some recovery.

"There was a massive impact from the huge slug of sediment that arrived in the Moreton Bay ecosystem," said research leader Professor Rod Connolly.

"Corals nearer to the Brisbane River mouth have been affected historically by past flooding. Unfortunately this has resulted in reduced diversity but the remaining species tend to be better adapted and have managed to cope with the flood water pulses they were subjected to.

"Most importantly we have discovered their ability to recover is improved where the algae doesn't overgrow the coral. This is evident from our research within the Bay's green zones. Having a small number of select areas where fishing is not permitted results in higher numbers of fish grazing on algae, which in turn maximises the chance for corals to recover.

"These green zones were highly contentious when first implemented three years ago, but we can now confirm real benefits in the face of the flood impacts," Professor Connolly said.

The ARI research has also monitored energy reserves within seagrass plants which shows that seagrass meadows near Stradbroke Island are in poorer condition than expected at this time of year as a result of the flood.

"These meadows are along the eastern side of the bay where the plants are rarely exposed to river water and they are now vulnerable to any major flooding this summer," Professor Connolly said.

"Seagrass habitat is critical food for dugongs, turtles and fish. With the unfortunate spike in dugong and turtle deaths reported during 2011, we are continuing to closely monitor this situation."

Green Times