Only a quarter of the 20,000 "ravenous" kingfish that escaped from a fish farm off Port Stephens last month have been caught.

NSW Department of Primary Industries announced on Wednesday that the temporary closure of the waters in Huon Aquaculture's Providence Bay research lease would stand until February 28.

A file photo of the Huon Aquaculture and NSW Department of Primary Industry commercial-size yellowtail kingfish trial site off Port Stephens. Credit:Sam Norris

The controversial farm, jointly run by Huon and the state government, was destroyed in rough seas in late January, resulting in 20,000 kingfish escaping from "fortress" pens.

Marine Parks' Association chairman and whale watching tour operator Frank Future described the fish as "voracious feeders".