Summary

Major floods in the upper reaches of the Richmond and Macleay river systems in February and March 2001 led to deoxygenation of the water in the lower reaches of these rivers. Evidence strongly suggested that most fish and crustaceans in these rivers were flushed, migrated actively from the river system or were killed by the anoxic water.

The rivers and adjacent inshore ocean waters were closed to all fishing following this fish kill for approximately four and a half months to provide the systems with time to recover. These fishing closures were lifted to allow limited recreational fishing on 1 July 2001 and fully lifted on 28 September 2001, by which time normal commercial and recreational fishing practices were allowed.

A series of scientific programs were initiated at the time of the kills to monitor the recovery of fish, crustaceans and water quality in the rivers. The enclosed final reports (each with their own lay summary) detail each of these studies. Scientific surveys were done every month for 12 months in each river using a variety of commercial fishing methods and scientific sampling techniques. In addition, intensive creel surveys of recreational fishing activities were done in each river for 3 months after the rivers were re-opened to recreational fishing. A small study was also done of the catches and by-catches occurring in the closed waters immediately outside the Richmond River using a chartered prawn trawler.

The data from the scientific sampling work showed that, by the time fishing restrictions were lifted, the populations of fish and crustaceans in the Richmond and Macleay rivers had recovered to levels that were sufficient to sustain normal commercial and recreational fishing practices. Some species appeared to recover relatively quickly in the main river channel to levels that have been more or less maintained since, while some other species took longer to recover.

The creel surveys revealed that the recreational fisheries in the Richmond and Macleay rivers were productive and providing quality recreational fishing opportunities after their re-opening, despite the adverse impacts of the February and March 2001 fish-kill events.

The small study done in the oceanic closure off the Richmond River showed that this closure was protecting significant quantities of prawns and small fish, especially juvenile mulloway.

The overall conclusion from this work is that closing these systems to fishing for the months after the fish kills allowed the systems to recover naturally to the point where normal commercial and recreational fishing could safely occur.