The company says 130,000 salmon escaped through a "significant tear" in a fortress pen in Storm Bay on Wednesday morning.

Early last week, the company lost more than 50,000 fish when a pen caught fire in the D'Entrecasteaux Channel, melting part of the structure.

The D'Entrecasteaux Channel operation and the Storm Bay pen are on either side of Bruny Island, south of Hobart.

Huon Aquaculture founder Frances Bender told the ABC the company was investigating both incidents, but insisted the latest "wasn't a failure of equipment".

"We are very concerned," she told Tasmanian Country Hour on Thursday.

"We are doing intensive investigations but as yet we've failed to find any operational cause for either incident.

"At this stage we can't see a reason for this occurring."