Escaped salmon ‘clueless and hungry’ after Huon Aquaculture farm damaged in storm

The fate of more than 100,000 farmed salmon that escaped a Huon Aquaculture pen during wild storms in southern Tasmania last year can now be revealed.

Salmon feeders washed up on Kingston Beach during wild storms in southern Tasmania in May last year. Picture: Shelly Belly

WHEN 120,000 farmed salmon escaped their pens during last year’s wild storms they were an angler’s dream, but posed an ecological nightmare.

New research has revealed the escaped fish survived up to four months in the wild — but remained fairly clueless and ended up extremely hungry.

Researchers from the Institute for Marine and Antarctic Studies were aided by 120 recreational fishers in studying the ramifications of the huge salmon escape in May last year.

FISHER FOLK RUSH TO CATCH ESCAPED SALMON

The anglers helped the researchers by reporting where they found the fish, the contents of their stomachs and their physical condition.

The mass escape occurred after a Huon Aquaculture fish pen broke apart off the east coast of Bruny Island in the May 11 storm that caused catastrophic flooding across southern Tasmania.

Huon Aquaculture founders Frances and Peter Bender. Picture: SUPPLIED

The pen was smashed apart by an industrial fish feeder that washed up on Kingston Beach.

Lead researcher Associate Professor Jeremy Lyle said the results showed the salmon, which were an introduced species from the Northern Hemisphere, did not fare well in the wild Tasmanian environment.

“They are just not well adapted to living in the wild,” Prof Lyle said.

HUON AQUACULTURE SAYS FISH LOSS EXAGGERATED

“They are farmed animals that have never been exposed to the natural environment and never had to learn to hunt.”

They were also naive in the face of being hunted.

“They are a little clueless in terms of dealing with predators as well,” Prof Lyle said.

“The odds are stacked against them.”

Although catches declined quite quickly due to the combined effects of fishing and predation from seals and sharks, those that did survive for several months were not thriving.

“There was only limited feeding by the escapees on native fauna,” Prof Lyle said.

“This is consistent with previous studies where farmed salmon seem to be poorly adapted to feeding on natural prey items.”

He said there was some evidence salmon had fed on crabs and small baitfish, but it was not widespread.

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Those that did survive for a number of months mainly did so by relying on their own generous fat reserves.

Rather than a threat to the environment, the fish became a bonanza for anglers trying their luck far and wide.

“We had no real preconceived idea about how far the salmon would go,” Prof Lyle said.

“We now know they do disperse rapidly once they do escape, they don’t hang around.”

The salmon dispersed around Storm Bay, the D’Entrecasteuax Channel, the River Derwent and Frederick Henry Bay. There were even reports from anglers of the fish swimming towards fresher water, in the Coal River towards Richmond and in the Carlton River towards New Norfolk.

Prof Lyle said developing a research response to these rare and unpredictable large-scale escape events was challenging.

“But the willingness of so many fishers to provide details of their catches meant that we’re now in a better position to understand the impact of these events,” he said.

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