Sharks are our seniors by about 450 million years. Yet in the last half century we’ve depleted some populations by 90%.
Of the world’s 1,200 or so known shark and ray species (rays can be thought of as sharks whose pectoral fins have transformed to wings), 17% are deemed threatened with extinction by the International Union for Conservation of Nature. But the percentage is doubtless higher because data on almost half the 1,200 are lacking. Species like angel and daggernose sharks are listed as “critically endangered.” The pondicherry shark may already be extinct.
Sharks can’t bounce back like other fish. Most give birth to dog-size litters, and those that lay eggs don’t spew big numbers. Sandbar sharks mature at age 16, then bear eight to 12 pups every other year at most. Embryos of the sand tiger swim around in each of two uteri, attacking and consuming siblings until only two survive. Duskies don’t mature until age 20, then deliver three to 16 pups every third year.
The shark crisis began with the economic boom in China and other East Asian nations. Before that most Asians couldn’t afford shark fin soup.
The slaughter has been staggering. Many countries in Africa, Asia, and the Middle East aren’t involved in global management treaties and, even if they were, lack resources to keep track of what shark species get killed in what quantity. Some countries with those resources are “playing games, cooking the books, and fishing illegally,” to borrow the words of shark biologist Greg Skomal of the Massachusetts Division of Marine Fisheries.
Shark depletion is dangerous in ways we can only begin to understand. It’s not just about sharks. Florida State University shark scientist Dean Grubbs notes that marine food webs are so complex that it’s hard to document “trophic cascades,” which occur when predator removal causes ecosystem parts to collapse like dominoes.
But trophic cascades are surely happening. Among the better documented examples is the proliferation of midlevel predators following shark reduction. These predators then deplete algae-eating parrotfish, and algae then smothers the reef. And where tiger sharks have been depleted, dugongs and green sea turtles are foraging on wider, richer sea-grass beds, possibly damaging them and communities they sustain.
In the 1980s and 90s some of the grossest and most wasteful shark carnage was happening in the US, which, having depleted species like cod, haddock, flounders, tunas, and swordfish, promoted exploitation of sharks as an “under-utilized resource.” Adding to the slaughter was a 1980 trade agreement with China and an obsession with sharks among anglers spawned by the 1975 movie “Jaws.”
With the growing demand in Asia, fishing boats from other poorly regulated nations and illegal fishermen plundered shark populations in all oceans, especially the Mediterranean and Indo-Pacific.
More Asian diners shun shark-fin soup
Recently, however, there’s been some good news about sharks. Peter Knights, director of WildAid — an international group committed to ending hurtful and illegal trafficking in wildlife — has gone so far as to proclaim that “the tide may at last be turning.”
Global fin trade is declining. During the last two years China, Hong Kong and Malaysia have banned shark fin soup at government functions. Five hotel chains have promised not to serve shark fin soup, and 26 airlines have agreed not to transport fins. WildAid reports that at least 76,000 people in Malaysia and 70,000 people in Hong Kong have signed its “I’m FINished with Fins” pledge.
In Beijing, Shanghai, Guangzhou, and Chengdu, 85 percent of people who responded to a WildAid survey reported that they’d stopped eating shark fin soup. Demand has fallen so dramatically that according to fin traders in Guangzhou, “shark fin is the same price as squid now.”
Trinidad-Tobago and New Zealand, huge shark fin exporters, banned finning in August and October respectively. United Arab Emirates imposed a ban in September. Australia, India, the U.S., the Dominican Republic, all of Central America, and the European Union have banned it, too. Now finning is illegal in about 100 countries. Some of these define the practice as slicing off fins and dumping sharks at sea, sometimes when they’re still alive. India, South Africa, Mexico, Canada, Argentina, the EU, and the U.S., for example, permit removal of fins only if carcasses are first brought to shore. That creates difficulties in handling and storage, making fin sale far less profitable.
Banning not just finning but trade in shark fins have been Cook Islands, Brunei, Bahamas, Northern Mariana Islands, Egypt, Fiji, French Polynesia, Guam, Marshall Islands, and the U.S. states of Massachusetts, Hawaii, Oregon, Washington, Illinois, California, Maryland, New York, and Delaware.
In September the 180-nation Convention on International Trade in Endangered Species of Wild Fauna and Flora protected the porbeagle shark, oceanic whitetip, great, smooth, and scalloped hammerheads, and all manta ray species by forbidding trade without certification that the take was legal and sustainable.
In November the 120 member nations of the Convention on the Conservation of Migratory Species of Wild Animals extended “Appendix II protection” (a pledge to devise management strategies) to silky sharks, two species of hammerheads, and all three species of threshers. Granted the same or stronger protections were all 9 species of mobula rays and all species of sawfish. Shark Advocates International president, Sonja Fordham — a fierce shark defender and not one to gush over international shark and ray initiatives — announced that she was “elated by the overwhelming commitment.”
The original version of this article appeared in Yale Environment 360 and can be accessed here.