Salmon seabed vacuum knockback in Tas

Tasmania's Environment Protection Authority has rejected a proposal by Salmon farming company Tassal to vacuum fish waste from the sea floor at Macquarie Harbour in the state's west.

The issue became controversial and inspired questions in parliament on Wednesday when neighbouring lease holders complained such previously untested dredging methods could impact environmental conditions in the harbour.

"I have advised Tassal that the (vacuuming) should not proceed given the uncertainty about the technique and unknown potential impacts on the environment in Macquarie Harbour," EPA director Wes Ford said in a statement.