Forty-one years ago, one of the biggest creatures on earth beached and died in a mangrove forest on the Northern Territory coast north-east of Darwin.

The blue whale was more than 25-metres long and probably weighed more than 136,000 kilograms.

A blue whale can grow to more than 30m in length and its calves are the biggest babies on earth.

An average blue whale eats around 40 million krill a day during their summer feeding season.

For several years the massive carcass lay hidden and rotting in the mangroves at Cape Hotham, near the mouth of the Adelaide River, 67 kilometres from Darwin.

It is not known who discovered it.

But over the next few years people started removing parts of the vertebrae and taking them home, probably unaware how rare blue whales are on earth.

Listed as an endangered species, environmental groups say there could be as few as between 10,000 and 25,000 blue whales left in the sea.

The sighting of a blue whale off the coast of Sydney in 2020 stoked the excitement of whale watchers.

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