Thousands of dead fish cover South Arm beach

Concerned residents are in shock after thousands of fish were found dead washed up on a local beach this morning. SEE THE PHOTOS + VIDEO >>

Heavy rain and irregular wind patterns have been blamed for tens of thousands of dead fish washing ashore south of Hobart on Saturday.

South Arm locals woke to a confronting scene as fish believed to be entirely jack mackerel lay sprawled along the beach for “kilometres”.

Nearby resident Rachel Todd saw the dead fish when she was walking her dogs at 6.30am.

“They were washed up on the beach and all appeared dead,” Ms Todd said.

“There were thousands of them, they were fairly thick on the beach.”

Ms Todd said she had lived at South Arm for 28 years and had “never seen anything like it before”.

“I’ve seen some in the street too, so the birds must have picked them up,” she said.

South Arm's George Vanderkelen, 18, with thousands of dead fish which have washed up on the beach.

Hungry seabirds feasted on the fish as they were washed back out to sea with the tide in the early afternoon.

University of Tasmania associate professor and marine expert Neville Barrett said the mass mackerel death was “not uncommon” at this time of year but where they washed up was unusual.

“When you have the first autumn rains and it’s quite heavy like we had last week, fish can end up swimming a fair way up the Derwent and getting caught in fresh water,” Prof Barrett said.

“The fresh water is toxic to some of those schooling marine species so it actually kills them – normally they are washing up in other places on the banks of the Derwent.”

Prof Barrett said recent south-easterly winds may be behind the fish washing up at South Arm instead.

South Arm's George Vanderkelen, 18, with thousands of dead fish which have washed up on the beach.

“(Mackerel) are an oceanic species and they can’t really tell if they’re going into fresh water, they will just enter it and get into trouble,” he said.

The news was not all bad for fishermen, with local apprentice carpenter George Vanderkelen eager to collect bags of the fish to use as bait. “I’m pretty keen to go home and get some plastic bags to fill up,” Mr Vanderkelen said.

“They are a pretty good size for it so they will be really handy on the water tomorrow.”

Originally published as Thousands of dead fish cover South Arm beach