UPDATE: The cause of death of 30 little penguins which washed ashore at Altona beach last Wednesday morning remains a mystery.
An interim post-mortem examination revealed the animals were of good body condition and disease-free.
There is speculation they may have drowned after being caught in a commercial fishing net.
A resident called authorities after he saw several dead penguins about 8am.
Officers from the Department of Environment and Primary Industries (DEPI), Fisheries Victoria and Hobsons Bay council scoured the shoreline and bagged penguins.
Zoe Hogg, of Earthcare St Kilda’s penguin team, said officers had no idea how the animals died.
“The last I heard was that they may have got caught in a fishing net,” she said.
“One fisherman once told me that he doesn’t usually get penguins in the net because they run across the top.’’
Wildlife rescuers assume the penguins were caught in a commercial fishing net because of they way they were found at the one location.
Ms Hogg said she didn’t believe it was possible for such a large number of penguins to die from natural causes.
Only one of the penguins had a microchip, which revealed it had originally come from a colony at St Kilda Breakwater. The penguin was microchipped in 2004, but had not been seen for eight years.
“You get the occasional Phillip Island one up here [at St Kilda], so I suppose the occasional one will go walking and find himself a new girlfriend,” Ms Hogg said. She said penguins often landed at Altona if they were sick.
DEPI regional director Travis Dowling said tests were continuing.
“A DEPI veterinary pathologist will undertake further tests to ascertain the cause. This is a sad and very unfortunate event.”
The bodies of five penguins were taken to La Trobe University on Wednesday afternoon, while the rest have been frozen.
Phillip Island has Victoria’s largest colony of little penguins. About 1200 penguins live at St Kilda.
The ‘little penguin’ is the smallest species of penguin, growing to an average of 33 centimetres high and 43 centimetres long.
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