Whales are the flagship for ocean conservation, and humpbacks are their most adored ambassadors. No other animal so embodies the intelligence, playfulness, song and society that strums human heartstrings.

That’s why humpbacks were the only nonhuman species included on the intergalactic calling card pinned in 1972 to the Pioneer 10 space probe – in the form of a recording of their song. They were also launched into the music charts in 1970 with an album that sold 10.5 million copies.

Their high profile is misleading, and we should tread cautiously when extending their good fortune to other cetaceans.

Not only are their numbers and habits more closely studied than any other species but killing them is recognised by whaling nations such as Japan and Iceland as bad for the tourist industry and a difficult public relations sell. Surveys of other whale species are much less accurate, and vary widely with every count. Whales are notoriously and surprisingly, given their size, hard to spot.

Like icebergs, the majority of their bulk is submerged, even when breathing, and a substantial amount of their time is spent far beyond the reach of biologists’ binoculars.

Whales won our love, and so saved themselves from near-certain extinction.

But just as we should be wary of thinking that humpbacks are recovering and so all whale populations are, we shouldn’t assume that a boost in whale numbers means that life in the ocean is recovering too. The umbrella of protection from the whale conservation movement doesn’t cover all whales, let alone the myriad species in the sea.

The Yangtze river dolphin now seems to be gone: the first mammal species to have been driven to extinction in 50 years.

Our increasingly desperate search for protein now leads to factory ships hoovering up krill – the tiny shrimp that many whales live on.

And, despite its importance, who has ever lost their heart to krill?

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