The waters around the controversial Port Stephens’ fish farm is alive with dozens of large sharks that have moved in for a feeding frenzy amid concern more kingfish have escaped.

Recreational fishermen described how they watched in awe as kingfish fell victim to a pack of as many as 10 bull sharks in the waters off Hawks Nest last week.

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 sharks - some more than three metres long – rushed the kingfish schools as they chased bait thrown in the water by fishers.

Melbourne’s Rob Verzin, visiting Port Stephens for an annual fishing trip, described the scene as “like nothing I’ve ever seen in 40 years of fishing”. Mr Verzin said a pack of 10 large bull sharks were “cruising the water” and using his boat as cover before smashing through schools of kingfish.