Efforts to ban the international trade in bluefin tuna

EXTINCTION comes in various ways. The dodo was done in by sailors who not only killed the birds themselves but also brought to Mauritius animals such as dogs and pigs that plundered their nests. Przewalski’s horse, which once roamed the steppes of Mongolia, is thought to have become too dispersed in the wild to breed. It was saved from extinction only because there happened to be some specimens in European zoos that were reintroduced to Mongolia in the 1980s. As efforts to prevent the bluefin tuna suffering a similar fate are increased, some conservationists wonder whether there will still be a breeding population left to save.

Bluefin tuna are a pelagic species: they live in the open waters, far beyond the reach (and governance) of individual nations. They are also one of those predators at the top of the ocean’s food chain, preyed upon mostly by man. They grow up to four metres (12 feet) in length, weigh as much as 250kg (550lb) and, when chasing prey—mostly sardines—can swim at a speed of 70kph (45mph). They also range widely, traversing the Atlantic Ocean to reach breeding grounds in the Mediterranean Sea. But what was once known as the common tunny has, over the past few decades, come to be at serious risk of extinction, thanks to overfishing driven by demand from Japan, where bluefin tuna are considered a delicacy and are used in sushi and sashimi. …