Sharks for supper? Why experts don't want a ban on shark fishing

Shark may not be on your menu tonight, but shark meat – especially shark fins – provides key protein for millions of people, and as their fishing is largely unregulated, sharks and their cousins face a growing risk of extinction.

Sharks, rays, and chimeras are confronting "possibly the largest crisis of their 420 million year history," wrote Colin Simpfendorfer and Nicholas Dulvy, two internationally recognized shark conservation researchers, in a recent article in Current Biology. That's bad news, not only for the more than 1,000 species of sharks, but also for nearly every ocean environment on Earth, where these predators keep other species in check.

The solution, the researchers say, isn't a total ban on fishing or selling shark parts – it's developing regulations to fish them responsibly. 

Most experts agree. In a recent survey of 102 shark researchers, 90 percent agreed sustainable fishing, not a ban on all shark fishing, should be the goal of shark conservation policy.

"There are two main reasons why bans on shark fishing don't work," says Dr. Simpfendorfer, director of the Centre for Sustainable Tropical Fisheries and Aquaculture at James Cook University in Australia.

First, most sharks aren't caught intentionally, they are inadvertent "bycatch" picked up by fisheries trying for other species, he explains in an email to The Christian Science Monitor.

And secondly, many communities in Southern Asia, South America, and Central America rely on shark and ray meat, he writes. "In fact, imports of shark meat into South America (especially Uruguay, Brazil and Argentina) have increased dramatically in recent years to fill demand for cheap animal protein."

A blanket ban on shark meat would force them to find other sources of protein, which could lead to other environmental damage, such as exploiting other fish species or clearing land to create pastureland for cows, he says.

Thanks to the 1975 film "Jaws," the word "shark" tends to evoke images of huge, hungry great white sharks, but scientifically speaking, the word refers to the 1,200 species of animals in the class Chondrichthyes. That includes rays, chimeras, and sharks from the tiny dwarf lanternshark, maxing out at around eight inches long, up to massive great whites that can grow up to 21 feet long and weigh 2,400 lbs.

And most of them are endangered or threatened, according to the International Union for Conservation of Nature, which analyzed the conservation status of 1,041 shark species in 2014. 

"Our analysis shows that sharks and their relatives are facing an alarmingly elevated risk of extinction," said Dr. Dulvy, co-chair of the IUCN Shark Specialist Group and co-author of the recent paper.

Scientifically managed fishing has rescued other species, including the spiny dogfish, a shark that hunts in packs in most of the world's oceans. The small shark, which tops out at about four feet long, "was heavily exploited in the 1980s, mostly to supply flesh to European markets," Simpfendorfer writes.

"However, through implementing catch limits as determined by scientists, the stock is now recovered and fished sustainably."

Sustainable fishing practices have helped other sea creatures, too, he adds. "There are a number of prawn fisheries in Australia that were badly overfished, but the implementation of sound management saw the populations recover and they are now sustainably fished; some are even MSC certified," he said, referring to the London-based Marine Stewardship Council.

Many shark species grow slowly and have few offspring, which has led some to argue that only a ban can protect them, but that's too simplistic, according to Neil Hammerschlag, director of the Shark Research & Conservation Program at the University of Miami, who conducted the survey of 102 experts and was not involved in the current research.

"Researchers believe that there is no single policy that will solve all shark conservation problems, and that the best policy choice is going to be situation specific," he said in 2015.

Solutions that most experts endorsed included species-specific bans to protect the most threatened species, quotas for the most prolific species, and outright bans for a few targeted areas, such as shark nurseries or bycatch hotspots.

Simpfendorfer and Dulvy include the first two of those recommendations in their current paper, along with bans on some fishing tools that produce the most bycatch, international treaties, assistance for developing countries, and tools to trace shark products to their source, so conservation-minded consumers can choose to support sustainably harvested shark meat.

"At present, the notion of sustainable shark fins is unthinkable to many," wrote the authors in their paper. But controversial fishing techniques such as the harvesting of fins from live sharks isn't the only way, they say.

"Sustainable shark fishing can be an important part of the solution to averting the crisis that sharks and rays face," says Simpfendorfer.