Daniel Pauly has been described as a rock-star scientist and I was fortunate enough to be guided by this eminent researcher through my graduate studies. Describing how industrial fishing has decimated fish stocks over the past 130 years, he explains why marine protected areas are needed to conserve some species and enable others to recover.
Industrial fishing began in the 1880s, when steam trawlers started to be deployed along the coasts of the British Isles. Frighteningly efficient, they soon liquidated coastal stocks of bottom fish – fish that had previously been exploited by subsistence and artisanal fisheries for centuries, even millennia, but had persisted.
The steam trawlers then had to expand their range into the open North and Irish seas and subsequently beyond, all the way into North Atlantic and Icelandic waters. The same expansion, but shifted a decade or so later, occurred with the nascent industrial fisheries of France, Germany, Russia, the United States and Japan. It’s a recurring pattern: the introduction of industrial fishing begets expansion because trawlers and other industrial fishing vessels (such as purse seiners) generate a pressure that generally cannot be tolerated by the species being targeted at a given fishing ground – and even less by the by-catch species, which are, by definition, subjected to unregulated fishing. Thus, one stock disappears after the other, and new stocks in previously unfished areas have to be found.
This depletion–expansion dynamic prevailed through much of the 20th century, albeit with the interruption of two world wars, which radically reduced industrial fishing and allowed fish to recover – if only temporarily – especially in the North Atlantic. In some areas, when this effect was strong, like in the North Sea, the recovery after a temporary reduction in fishing established the principle not only that stock abundance was inversely related to fishing intensity, but also that overfished stocks could recover, and some within a few years. In the last quarter of the 20th century, some countries, for example the US and Norway, built on this to counter the depletion–expansion dynamic of their fisheries. They allowed the stocks they had overexploited to rebuild, which the stocks did and now support vibrant ‘new’ fisheries.
In most other countries, however, the depletion–expansion dynamic continued. Thanks to their onboard technology, trawlers and other industrial vessels could fish anywhere in the world, in deep or shallow waters or far from coastlines, and in conditions from tropical to polar. These developments meant that previous obstacles to fishing – depth, distance, ice cover and inclement weather – could now be overcome. We could fish everywhere, anytime we wanted. And we did.