Nowhere to hide: The onslaught of fishing technology

In the past, sail-powered fishing boats were limited by wind and weather; today’s factory ships, with sonar and GPS, can scour the sea for months.

Greenpeace/ZUMA Press/NEWSCOM/FILE
An unmarked, unflagged factory fishing trawler cruises off the coast of Sierra Leone in west Africa. Bottom trawling is very destructive of the marine environment and indiscriminate in its catch. With flash-freezing equipment on board to preserve its catch, such vessels can stay at sea for months at a time.
Mary Knox Merrill / Staff
Modern fishing technology includes a GPS monitor (top right in photo) for precise location and navigation, sonar (center) to detect the water depth and schools of fish, and (in this case) a screen showing live video (top left) from a camera mounted on a clam dredge below. While technology has made fishermen much more efficient, more efficient fishermen need not spell the end of all fish. Fishery management schemes that encourage stewardship rather than a ‘race for fish’ can lead toward sustainable fishing methods.

Late 1800s
The first steam-powered trawlers began plying the seas around the British Isles. Previously, fishing boats were powered by oar or sail. Now, coal-fired boats could trawl regardless of wind or tide. The industrialization of the world’s fishing armada had begun.

Post-World War I
Fishing fleets adopted the diesel engine, invented earlier but perfected during wartime.

Post-World War II
Radar, also developed for the military, becomes standard aboard fishing boats. Fishermen could now easily sail through darkness and fog. Newly available sonar (also developed during the war) let them locate fish more easily.

When fisheries became depleted near home, European fleets began looking farther out to sea. (North Sea stocks had rebounded, briefly, when fishing halted during both world wars. But the bounty was quickly scooped up.) New fishing boats were built for travel to distant waters.

Flash-freezing technology allowed for immediate preservation and storage of the catch. (Before, ice had been used; before that, salt.) Time and distance were no longer objects. Eastern European countries adopted the technology and built huge factory trawlers. Fleets with onboard movie theaters, doctors, and operating rooms accompanied them. By the 1970s, these ’floating cities’ were fishing the entire Atlantic.

‘Bobbin’ trawlers were now widespread. Metal discs threaded on chain let these large nets roll across the ocean floor. Fishermen had to avoid rocky areas, however, which would snag the net. But by mid-decade, rubber truck tires had replaced the metal bobbins. The new ‘rockhoppers’ could bounce over rough underwater terrain.

Global fish catches peak at 80 million metric tons. Since then, the global catch has declined half a million metric tons per year.

Global Positioning Systems (GPSs) became commercially available, along with newly declassified maps of the ocean floor dating from the cold war. Trawlers could much more easily fish the mountains and trenches of the deep sea.

According to the United Nations’ Food and Agriculture ­Organization, one-quarter of the world’s fisheries are overfished, up from 10 percent in the mid-’70s. Another 50 percent are fully exploited. If current trends continue, some scientists say, all the world’s fisheries will have collapsed by 2048.

[Editor's note: The original story was accompanied by a different main photo. Another image was substituted to better represent the theme of the story. The original caption with the secondary photo was recast so as not to single out any fisherman in particular.]

Empty Oceans, a series on the state of the world's fisheries, will be appearing in the Monitor's environment section. For the full series, click here.

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