According to a study published in Nature last month, oceanic shark numbers have declined by 70 per cent since 1970. Three-quarters of ocean-going shark and ray species are now threatened with extinction. Yet we are still more likely to feel that sharks are a threat to us than the other way round. Peter Benchley’s novel Jaws – both symptom and cause of that feeling – was published 46 years ago, in February 1974. Production of the movie version began that summer, filmed in the village of Menemsha on Martha’s Vineyard. A few years ago I went for a swim at the beach there. I had never considered myself afraid of sharks. But with every stroke I glanced backwards over my shoulder towards the open water.

Leviathan – showing in (a very few) cinemas in London from tomorrow – is a portrait of a commercial fishing trawler, its crew, their haul and the ocean that surrounds them. Made by Harvard’s Sensory Ethnography Laboratory, Leviathan strands its audience at sea, hurls you around and then slowly drowns you – first in fish guts, then in a dark watery abyss. The directors, Lucien Castaing-Taylor and Véréna Paravel, were inspired by Moby-Dick; they read aloud from the novel on deck while filming.

The four most ‘informative’ words in Moby-Dick, statistically speaking, are ‘I’, ‘whale’, ‘you’ and ‘Ahab’. Marcello Montemurro and Damian Zanette worked this out by comparing the text of Moby-Dick to all the possible alternatives obtainable by shuffling Melville’s words into random sequences. These are not the four words that are used most often, or that carry the most ‘information’ in the everyday sense of the term, but the words whose positioning in the original, meaningful text differs most from the way they would be scattered in all other permutations. The ‘information’ here is of the mathematical, measurable kind: ‘most informative’ means ‘least randomly distributed’. It may seem a slightly odd way to try to quantify semantic content, as though when Melville wrote Moby-Dick, it wasn’t so much a matter of finding the right words, as of putting them down in the right order.

'What makes Melville Melville is digression, texture, and weirdness,' says Damion Searls. No, said Orion Books in 2007, all that extraneous business just gets in the way of the story arc. Without all that whale stuff, you could make a readable book. Hey, maybe someone could make an action movie. The result was Moby Dick in Half the Time (which you can buy in a bargain bundle at Amazon with Vanity Fair in Half the Time and Anna Karenina in Half the Time). 'All Dick and no Moby,' said Adam Gopnik in the New Yorker. Moby Dick is the novel you read to see what novels can be, and for delight.