Fishermen and scientists questioning how many fish can be sustainably taken from a reef believe they've quantified the tipping point.

Nick Graham, from the ARC Centre of Excellence for Coral Reef Studies at James Cook University, says ecosystems may take decades to recover from overfishing to feed the world's growing population.

In a report released today, researchers have demonstrated how overfishing can generate a predictable sequence of events that lead to the collapse of reef ecosystems.

It also offers targets in order to keep fisheries sustainable.

As "fish biomass" - the number and weight of fish living on a reef - declines due to fishing, a number of tipping points are crossed, from which it is increasingly harder to return.