“Towards thee I roll, thou all-destroying but unconquering whale; to the last I grapple with thee; from hell’s heart I stab at thee; for hate’s sake I spit my last breath at thee.” Captain Ahab’s splenetic, dying declaration of defiance, as Moby Dick destroys his whaling ship and sends it below the waves of the Pacific Ocean, is among the most famous passages in Herman Melville’s extraordinary novel.

In reality, such triumphs of the hunted over the hunter were a fantasy in the brutal world of industrial whaling. The biggest cetacean of them all, the blue whale, had all but disappeared from the Southern Ocean by the time a ban on hunting it was introduced in 1967.

Sightings of the largest mammal ever to live on the Earth had been vanishingly rare in the region since then. Not any more. A survey of coastal waters around the island of South Georgia in the sub-Antarctic, has yielded remarkable, uplifting results. In just over three weeks, in the krill-rich waters of what was once their principal feeding ground, the movements of 55 Antarctic blues were recorded by the British Antarctic Survey. The finding was described as “truly, truly amazing” by one cetacean specialist. It suggests that when a comprehensive audit, due in 2021, is carried out, there is a good chance that the species will prove to be in full recovery mode, as are humpbacks and other whales in the southern hemisphere.

The blue whale belongs to the category of “charismatic megafauna” – a rather unattractive way of describing those animals which capture the public imagination and help drive environmental and biodiversity campaigns. Three years ago, the Natural History Museum installed a 25m skeleton of a blue and named it Hope, intending to inspire new generations to build a sustainable future.

There has been criticism of this kind of approach, some of it on the grounds that the fate of creatures with less obvious appeal can be ignored. But the return of the world’s most majestic ocean travellers to southern waters should serve as a showpiece for wider possibilities of conservation. Ecological wrongs can be righted, or at least mitigated, with sufficient will and organisation.

The more general comeback of the whale – for which environmental campaigners should take a great deal of credit – can be an inspiration for victories yet to be won. It could also, conceivably, act as an added spur to action on the climate emergency. Twenty-first century Captain Ahabs are limited to a few stubborn whaling outposts these days; but warming oceans, which disrupt food chains and migratory rhythms, are becoming a lethal threat.

Of the 55 blue whales identified, some were seen but others were only heard through recorded audio. Their song recalls somewhat the deep, resonant sound of a tuba. The music of the southern seas was not the same without these orchestral manoeuvres in the dark. We must ensure the Antarctic blue is back to stay.