Tasmania’s Department of Natural Resources and Environment said 157 false killer whales were beached in the past 48 hours near Arthur River on the island’s north west.
The agency said the remaining creatures had grown increasingly “stressed” and would be euthanised after attempts to refloat them failed.
“Following expert veterinary assessment, we have made the decision to euthanise the animals,” incident controller Shelley Graham told reporters.
“That’s likely to be the course of action for all 90.”
Earlier on Wednesday, state wildlife officer Brendon Clark said efforts were made to save several whales, who like orcas are part of the dolphin family, and can weigh more than one tonne and grow up to six metres. But Clark said the isolated location complicated the rescue and deployment of necessary equipment.
