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Bio­di­ver­sity


A Col­lec­tion of News by Moos


201418Aug07:03

The State of Sharks, 40 Years After Jaws

Infor­ma­tion
pub­lished 18 August 2014 | mod­i­fied 18 August 2014
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We could be at a tip­ping point for con­serv­ing the infa­mous preda­tors, if we can keep up shark-​friendly prac­tices.


Great white sharkThis year marks the 40th anniver­sary of the pub­li­ca­tion of Jaws the book, and next year will be the 40th anniver­sary of Jaws the movie. It was Peter Benchley’s first novel, and the film, directed by then 27-​year-​old Steven Spiel­berg, was the first sum­mer blockbuster.

In the public’s mind, the fear of sharks that Jaws ini­tially inspired was soon replaced by fas­ci­na­tion, which con­tin­ues to this day. Sadly, that fas­ci­na­tion has been joined with despair over the last sev­eral decades, as evi­dence has accu­mu­lated that shark pop­u­la­tions are plum­met­ing, dri­ven by over­fish­ing. Peter Bench­ley often stated in later years that he could never again write a book like Jaws, and he devoted much of his post–Jaws career to ocean conservation.

I see the sea today from a new per­spec­tive, not as an antag­o­nist but as an ally, rife less with men­ace than with mys­tery and won­der. And I know I am not alone. Sci­en­tists, swim­mers, scuba divers, snorkel­ers, and sailors all are learn­ing that the sea is wor­thy more of respect and pro­tec­tion than of fear and exploitation.
Peter Bench­ley, writer of the novel ‘Jaws’ »

How did sharks get into such trou­ble in the first place? Sharks and their rel­a­tives have been around for more than 400 mil­lion years and sur­vived four mass extinc­tions. Yet they are sur­pris­ingly vul­ner­a­ble to human fish­ing because, like many long-​lived organ­isms, they repro­duce slowly. Great white sharks, for exam­ple, may live to be 70 years old or more. Spotty data sug­gest that females pro­duce on aver­age five baby great whites at a time but give birth per­haps only every other year, start­ing at about 15 years of age.

So it is no sur­prise that shark pop­u­la­tions have not been able to keep up with losses caused by a world­wide hunt­ing frenzy. Demand for shark fins, often served in Asia as shark fin soup for wed­ding ban­quets, New Year’s fes­tiv­i­ties and gov­ern­ment func­tions, sky­rock­eted for decades, lead­ing to esti­mates of 100 mil­lion sharks being killed every year. This trans­lated to a loss of about 6 to 8 per­cent of all sharks annu­ally, a rate that can­not be sus­tained by pop­u­la­tions that typ­i­cally only increase by about 5 per­cent a year.

Yet lately, after years of shark doom and gloom, some good news has started to appear. How did the sit­u­a­tion start to turn around? You can chalk it up to bet­ter fish­ery man­age­ment, falling demand for shark fins and ris­ing appre­ci­a­tion for live sharks.

Rules and poli­cies designed to pro­tect sharks include shark sanc­tu­ar­ies, ban­ning of shark finning (the tak­ing of just the valu­able fins and dis­card­ing the often still-​living shark), pro­hi­bi­tions on sell­ing and ship­ping of shark prod­ucts and changes in fish­ing gear that reduce the like­li­hood of sharks being caught by mis­take. Thanks to grow­ing pub­lic dis­gust with the prac­tice of finning and aware­ness of cat­a­strophic drops in shark num­bers, demand for shark fin soup is declin­ing in Asia (as are shark fin prices). The Chi­nese gov­ern­ment recently banned the serv­ing of shark fin soup at offi­cial func­tions, a num­ber of large hotels have taken shark fin soup off the menu and a grow­ing list of air­lines are refus­ing to trans­port shark fins.

In places where tourism is crit­i­cal to the local econ­omy, the real­i­sa­tion that sharks are much more valu­able alive than dead has also prompted legal pro­tec­tion. More than 30 per­cent of the Mal­dives’ econ­omy is based on shark eco-​tourism, and in Palau it was esti­mated that a shark that brings in $108 dead is worth $1.9 mil­lion alive over its life­time. As a recent head­line in the New York Times noted in a story about shark tourism on Cape Cod (not far from where most of Jaws was filmed): “They’re Going to Need a Big­ger Gift Shop.”

Most impor­tantly, bit-​by-​bit, sci­en­tists have been find­ing evi­dence that shark num­bers in some areas are slowly rebound­ing. A report this year sug­gested that num­bers of great white sharks seem to be increas­ing along the east coast of the United States, and sim­i­lar trends have been reported from Cal­i­for­nia, South Africa and Aus­tralia. Notably, these are all places where har­vest of these sharks has been pro­hib­ited since the 1990s. Such devel­op­ments inspire cau­tious opti­mism: we could be at a shark con­ser­va­tion tip­ping point.

Of course, there is still plenty of cause for con­cern and much work to be done. Some sci­en­tists dis­pute the more opti­mistic num­bers, not all laws are well enforced and no one is argu­ing for a relax­ation of global efforts to con­serve sharks. Of the 476 species of sharks analysed by the Inter­na­tional Union for the Con­ser­va­tion of Nature for extinc­tion risk, good data are only avail­able for 276, and of these 123 are con­sid­ered at risk for extinction.

Map of shark pro­tec­tion through time:



(Source: Smithsonian’s National Museum of Nat­ural His­tory YouTube chan­nel)



Still, it is impor­tant to cel­e­brate the suc­cesses we do have. Around the world, shark-​friendly mea­sures are spread­ing rapidly (see the map above), and there is enor­mous power in the real­i­sa­tion that one’s con­cerns and efforts are part of a larger and grow­ing effort.



(Source: Smith​son​ian​.com sci­ence news, 12.08.2014)


UN Biodiversity decade

Goal: 7000 tigers in the wild

Tiger range countries map

Tiger map” (CC BY 2.5) by Sander­son et al., 2006.

about zoos and their mis­sion regard­ing breed­ing endan­gered species, nature con­ser­va­tion, bio­di­ver­sity and edu­ca­tion, which of course relates to the evo­lu­tion of species.
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