Petuna Seafood Deepwater Fishing has sought approval by the Australian Fisheries Management Authority to charter a 104-metre vessel to fish blue grenadier for two months off the West Coast of Tasmania.

The vessel, Meridian 1, will avoid the super trawler ban because it is under 130 metres long, but the move has been criticised by environment groups.

Meridian 1 is a Ukrainian factory freezer trawler chartered by New Zealand fishing giant Sealord.

Environment Tasmania marine spokeswoman Rebecca Hubbard said the vessel had a Dominican Republic flag, and the practice of registering vessels in countries unrelated to ownership often occurred to avoid regulations, and was known as operating under a "flag of convenience". But PSDF director Les Scott said the ownership of the vessel did not determine how it would operate when chartered, and strict environmental practices would continue to be applied.

"The practices and procedures are set by PSDF, which charters the vessel, not the vessel's owner," Mr Scott said. "PSDF has used factory vessels in the fishery since 1997 because part-processing and freezing of soft fish such as blue grenadier is the only way to delivery a quality product to the market."

Mr Scott said Meridian 1 would fly the New Zealand flag when it came, and the company's intention to use the vessel was advertised publicly in January. Liberal Senator Richard Colbeck said environment groups were running a "cheap and nasty" campaign.

"Australia's blue grenadier fishery is sustainable and well managed," Senator Colbeck said.

"The condition of the spawning stock is so good that quotas in the fishery were increased this year."

The vessel is set to create 50 casual jobs in the Devonport area.