Shane Pritchard

And warn against overstocking salmon pens

TASSAL was in receivership in 2002 when receiver manager Korda Mentha acquired another salmon company, Nortas, and the combined business was floated on the stock exchange in October 2003.

In 2005 the new Tassal merged with a third salmon company (Aquatas) which is now the basis of Tassal today.

In 2005 the combined HOG (head on gutted) production of the merged companies was about 12,000 tonnes. Tassal has doubled production since.

Two major costs with growing salmon in Tasmania are freshwater bathing to treat amoebic gill disease and keeping seals out of the cages.

Tasmania is possibly the warmest environment in the world where salmon are grown and there is an amoeba that thrives here.

Seals seem to be growing in number. Tassal had to remove and relocate 151 from its southern farms in 2016 and 2131 in 2017.

The two costs would equate in some years to about $2/kg in production costs.

To maximise profit and grow the business, the accountants looked at the cost of production and concluded Macquarie Harbour was the answer. Why? First, there was no expensive bathing required as the huge freshwater inflow to Macquarie Harbour meant the salmon were not affected by the amoeba found in southern farms and, secondly, the freshwater kept seals away. Seals can exist in freshwater, but it is not their preferred environment.

The Tassal that went into receivership had never farmed in Macquarie Harbour, but the new Tassal had picked up two leases there from the merger with Nortas and Aquatas.

Nortas and Aquatas had been conservatively farming in Macquarie Harbour for several years, producing sterile fish known as triploids to meet off-season supply in March and April when the normal fish on southern farms were not yet up to size for harvest.

Tassal put a plan together to ramp up salmon production from the low-cost Macquarie Harbour sites. In addition to the two sites they had, Tassal secured a third site known as Lease 266 and over the past 10 years has produced in excess of 10,000 tonnes per annum from Macquarie Harbour.

Macquarie Harbour has been responsible for nearly