Beaked whale skeleton helping scientists

DBCA research scientist Dr Holly Raudino, Dr Nahiid Stephens (Lecturer in Veterinary Pathology Murdoch University) and Dr Kenny Travouillon
Curator of Mammalogy (Mammals) WA Museum, exhume the skeleton of a rare Andrews' Beaked whale  washed up on Swanbourne beach in 2018. Photo: Andrew Ritchie
DBCA research scientist Dr Holly Raudino, Dr Nahiid Stephens (Lecturer in Veterinary Pathology Murdoch University) and Dr Kenny Travouillon Curator of Mammalogy (Mammals) WA Museum, exhume the skeleton of a rare Andrews' Beaked whale washed up on Swanbourne beach in 2018. Photo: Andrew Ritchie

THE body of a rare whale is allowing scientists to understand both the species and marine pollution after its skeleton was exhumed at the WA Museum depot in Welshpool last Wednesday.

The 4.5m, 1.5-tonne Andrews’ beaked whale washed ashore dead on Swanbourne Beach in November, 2018.

The deep-water species is known only by about 35 strandings in Australia and New Zealand, and the museum had only two skulls before the complete skeleton was uncovered.

After a Murdoch University necropsy of the carcass, most of the flesh was removed and remainder frozen before it was partially buried and covered with mushroom straw at the depot since last August.

The burial allowed animals, bacteria and insects to remove any remaining tissue.

Knowledge of Andrews’ breeding, feeding, mating and other behaviours is extremely limited, but  Department of Biodiversity, Conservation and Attractions research scientist Holly Raudino said strandings of the similar Grey’s beaked whale near South West capes in summer indicated beaked whales may come close to shore at that time, but the necropsy showed the Swanbourne whale was a sub-adult male.

WA Museum curator of mammals Kenny Travouillon said the examination showed the jaw only opened about 15cm, and it was thought this was because the mammal sucked in food, mainly deep-diving squid.

Tests of squid beaks in its stomach failed to determine where it had been feeding, and there was no clear cause of death because it had good body weight.

The whale had not been struck by a boat and tissue tests indicated no poisoning.

Toxicology tests of the whale’s liver before the burial did indicate how highly toxic per- and polyfluorinated alkyl substances (PFAS) used in fire retardants, waterproof clothing and industrial lubrication have reached the remotest parts of the Indian Ocean.

Murdoch University’s Nahiiad Stephens said the tests showed low levels of the man-made toxins in the liver, and that information would be vital in creating a baseline of data about how the pollution affects marine mammals in both the Swan River and the eastern part of the ocean.

“We can no longer consider that environment to be pristine anymore,” she said.

The skeleton will become part of the WA Museum’s research collection and is unlikely to be displayed at its new Northbridge home unless there is a special exhibit.