“Oceans account for 96% of all habitable space on Earth,” says Chris Armstrong in the London Review of Books. Yet many of the species that “once teemed in their millions” in these waters have been “harried close to extinction” by industrialised fishing. For every 300 green turtles that once swam in the Caribbean, just one remains. Nine in 10 of the world’s large fish and oyster beds have gone. “Seagrass meadows are disappearing at a rate of 7% per year.” This deep-sea decimation has required an “immense, dogged effort” by fishermen, using “nets that could swallow a Boeing 747” and longlines – fishing lines carrying vast numbers of baited hooks – “that extend for 100km”.
The industry tries to present itself as “the custodian of marine life”. It’s anything but. Global catches have been dropping since the 1980s. “A typical wooden fishing boat in 1900 could catch 16 times more fish in an hour than its contemporary equivalent.” And industrial fishing techniques damage not only the seabed but also the planet as a whole: “bottom trawling alone releases as much carbon as the entire aviation industry”. The good news is that the oceans “can still recover some of their lost plenitude”. In Marine Protected Areas, where fishing is limited or forbidden, populations return to health “in surprisingly short order”. Tens of thousands of oysters that were brought to the Solent, for example, now “spawn larvae in their billions”. The big problem is the high seas, which aren’t governed by any state and where fishing is a free-for-all. Unless we can find a way to protect them, the ravaging of “the world’s largest ecosystem” will continue.