North Atlantic Swordfish on Track to Strong Recovery
for National Geographic News
|November 1, 2002|
North Atlantic swordfish populations, which had been severely depleted
by the 1990s as a result of overfishing, have staged a stunning
recovery, reports an international regulatory group charged with
overseeing their protection.
Most remarkable is the fact that the recovery occurred in just three years. A 10-year conservation plan placing strict limits on commercial fishing of the species was imposed in 1999.
North Atlantic swordfish have multiplied to such an extent that biologists say the population has reached the 94 percent mark of the number needed to guarantee their survival and allow controlled commercial fishing to continue indefinitely.
"This is good news for those who care about the long-term health of the North Atlantic swordfish," said Bill Hogarth, director of fisheries at the National Oceanic and Atmospheric Administration.
David Wilmot, director of the Ocean Wildlife Campaign, concurs.
"The new assessment of the status of the North Atlantic swordfish population indicates that efforts to recover the population are working and rebuilding is ahead of schedule. This is great news," he said.
The Ocean Wildlife Campaign, a coalition of environmental groups that includes the Wildlife Conservation Society, the World Wildlife Fund, and the National Audubon Society, has lobbied hard to protect the species.
The preliminary assessment was issued by a working group of the International Commission for the Conservation of Atlantic Tuna (ICCAT) at a meeting held in September in Madrid. ICCAT was formed in 1969 under a treaty designed to protect populations of tuna, swordfish, marlin, and other large oceangoing commercially fished species.
Open-sea fish populations across the globe have experienced dramatic declines in recent decades. Scientists attribute the declines to pollution, habitat degradation, and unsustainable fishing practices that allow species to be harvested faster than they can reproduce.
Species currently threatened by overfishing include the Atlantic cod, the black sea bass, the red snapper, and some sharks.
Swordfish (Xiphias gladius) migrate great distances and are an important commercial fish to many countries. They can be found in the North Atlantic, South Atlantic, Mediterranean Sea, and Pacific and Indian Oceans. Scientists know relatively little about swordfish populations in the last two of these regions.
People have hunted swordfish throughout history using harpoons and conventional fishing lines. Swordfish caught this way are typically large, sexually mature individuals, said Elizabeth Babcock, a conservation biologist with the Wildlife Conservation Society.
Fishing became a great threat to the species with the development of commercial longline fisheries in the 1960s. Longlines are fishing lines that can stretch over dozens of miles and are baited with hundreds of hooks.
Juvenile swordfish and other severely depleted species are often accidentally caught by longlines. The problem, known as bycatch, is a huge issue for some species. ICCAT statistics indicate, for example, that 95 percent or more of white and blue marlins caught are taken accidentally by commercial boats fishing for swordfish and tuna.
"Unlike the harpoon and sport fisheries, the longline fishery is very efficient at catching swordfish of all ages throughout their range," said Babcock. "The catches in the 1990swhich peaked at 38,600 metric tons in 1995were much higher than the population could sustain."
The average North Atlantic swordfish caught in the 1960s weighed 250 pounds. By the late 1990s, the average was 90 pounds.
In 1999 ICCAT estimated that swordfish numbers had dropped to one-third of the size the population would have been without fishingand far below levels that would allow fishing to continue without driving the species to extinction.
In response to the dire situation and continued pressure from environmental groups and the United States delegation, ICCAT introduced a 10-year recovery plan to rebuild North Atlantic swordfish stocks. The plan limited international fishing quotas to about 10,000 metric tons annually. The numbers were to be reviewed this year.
In August 2000, the United States closed an additional 132,670 square miles (343,610 square kilometers) of Atlantic swordfish nursery waters to longline fishing.
"If recent catch levels continue, there is more than an 80 percent chance that the population will recover [completely] by 2009 or even sooner," said Babcock.
Environmental groups will have to maintain their vigilance and continue to lobby ICCAT to keep fishing quotas low enough to ensure the recovery is sustained, she said.
"This is an incredible victory for conservationists, commercial fisherman, consumers, and, of course, swordfish," said Ellen Pikitch of the Wildlife Conservation Society. But "the battle is far from over," she said.
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