Sparks: Hooked on tuna: People have been harvesting these ocean predators for 44,000 years

Forty-four millennia of bone heaps and painted vases record not a partnership with the sea but a hunt that never ended, and the fish that once outnumbered the hunters now learn what the weak learn from the strong.

Goodwill toward the ocean has never restrained a fleet; only quotas with teeth, enforced by powers that lose revenue when the stock collapses, will make conservation rational rather than pious.

Men fished with bone hooks for four hundred centuries and the sea held; then the dynamo arrived, and the acceleration of the harvest outstripped every institution built to govern it.

We have hunted the same fish since before we could write, and at three in the morning I admit what daylight forbids: it was never hunger, it was the need to prove something was ours to take.

Man has been catching tuna for forty-four thousand years, which shows admirable persistence, and the fish would surely admire it too if any were left to do the admiring.

Wager on the stock enduring and lose the bet, and no abundance returns to console you; the arithmetic of the deep punishes confidence far more severely than it rewards it.

Forty-four thousand years of chasing one fish across an ocean, and they call the dog uncivilised for eating what walks past his nose.

What is known: the harvest has run forty-four millennia. What is assumed: it can run forty-four more. The premises and the conclusion are separated by the whole of arithmetic.

The ancient bones tell of abundance; the fishmonger's ledger tells what a tin now costs, and the housewife doing Tuesday's sums understands the depletion the reports only describe.

We call the endless harvest natural, then cite four thousand generations of practising it as proof that no other way was ever possible - a circularity perfected long before the vases were painted.

A fisherman mends his net exactly as his predecessors did on shores I have never seen, and the continuity of the hands, not the size of the catch, is the detail the paintings preserve.

The harvest has continued pleasantly for forty-four thousand years, and we are assured the ocean, being vast and benevolent, will absorb the trawlers as graciously as it absorbed the hooks.

That the sea's bounty is endless has been common sense since before the frescos were painted, and the men who own the fleets have never once had to force anyone to believe it.

Things that endure: a painted fish on an ancient vase, the silver flash of the catch at dawn, the belief that the sea will always provide - and of these, only the last is in danger of fading.