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More adventurous than the average bear

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Sunday, October 13, 2013

Is your bowl of shark's fin driving a species to extinction?

It is common to see assertions by anti-Shark's Fin activists that shark populations are in danger of collapse due to overfishing.

Given that I knew that there were over 200 species of sharks, I was wondering if there wasn't a conflation of species, such that all of them were gathered under the general label of "sharks", said to all be in peril.

So I decided to investigate the issue myself.

Anti-Shark's Fin activists are leary of using CITES (Convention on International Trade in Endangered Species) classifications, since they say that CITES is formulated primarily with commercial considerations, so I decided to look at IUCN (International Union for Conservation of Nature) data.

There are in fact 477 species of sharks according to the IUCN. Unfortunately the data was not in a usable format, but I have cleaned up and restructured it. Here're the summary statistics:

Conservation Status Number of species
DD (Data Deficient) 214
LC (Least Concern) 121
NT (Near Threatened) 69
VU (Vulnerable) 48
EN (Endangered) 14
CR (Critically Endangered) 11
EW (Extinct in the Wild) 0
EX (Extinct) 0
All 477

Removing the data deficient species (where there is not enough information to assess their conservation status) and the extinct ones (incidentally, none) produces some interesting results:

Conservation Status Number of species % of Total
LC (Least Concern) 121 46%
NT (Near Threatened) 69 26%
VU (Vulnerable) 48 18%
EN (Endangered) 14 5%
CR (Critically Endangered) 11 4%
All 263 100%

So of all the shark species for which enough data exists to determine their conservation status, 46% are in the Least Concern category and 72% are either in Least Concern or Near Threatened. Species which are of "Least Concern" are not endangered (in any but the broadest sense of the word) and "Near Threatened" species are not endagered either.

With the help of the Marine and Land Products Association (MPA), an organization comprised of local businesses in the fishing & marine industry whose mission "is to promote full utilization of sustainable seafood" and which represents all shark's fin traders in Singapore, I have identified the 21 species used for shark's fin (at least in Singapore) and mapped them to their conservation status:

Common Name IUCN Red List Status
Angel Shark CR
Argentine Angel Shark EN
Australian Angel Shark LC
Australian Blacktip Shark LC
Blue Shark NT
Bronze Whaler NT
Common Thresher Shark VU
Grey Gummy Shark LC
Japanese Velvet Dogfish DD
Porbeagle VU
Sand Tiger VU
Sandbar Shark VU
Scalloped Hammerhead EN
Shortfin Mako VU
Silky Shark NT
Smalleye Hammerhead Shark VU
Smooth Hammerhead VU
Speckled Carpet Shark LC
Tiger Shark NT
Whitetip Oceanic Shark VU
Whithound (School Shark) VU

(The Basking Shark (Cetorhinus maximus - VU) and Whale Shark (Rhincodon typus - VU) are no longer traded by the association)

This makes for 21 traded species out of 477: only 4.4% of shark species are traded in Singapore. Of the 21, only 3 are endangered or critically endangered, and the MPA informs me that domestically traded shark's fin is mostly from sustainable species such as Blue Sharks, Whithounds (School Sharks) and Grey Gummy; statistics on the species traded will be released once business confidentiality concerns have been resolved. Meanwhile, the MPA "have continuously encourage end users to move towards less endangered and species that are properly managed and utilised".

So as we can see, the occasional bowl of shark's fin isn't going to lead to marine armageddon.

Indeed, many types of seafood that we happily eat every day are endangered:

- Atlantic Bluefin Tuna (Thunnus thynnus - EN) (especially popular in sushi)
- Atlantic Halibut (Hippoglossus hippoglossus - EN) (farmed halibut is available, but Greenpeace says that there is a high risk that the halibut you buy comes from unsustainable fisheries)
- Beluga (aka Beluga Sturgeon; Huso huso - CR) (this is where the most expensive caviar comes from)
- Chilean Seabass (aka Patagonian Toothfish; Dissostichus eleginoides - there doesn't seem to be an IUCN red list status for this but it's known to be overfished)
- Southern Bluefin Tuna (Thunnus maccoyii - EN)

A dogged obsession with shark's fin, then, risks missing the forest for the trees and ignores the medium-long term sustainability issues related to other types of seafood which are often more pressing than for sharks.

Fun fact: the "elephant shark" (Callorhinchus milii, aka Australian ghost shark, Makorepe, whitefish, plownose chimaeras or elephant fish) is used for Shark's Fin. However, it is not really a shark.

Dataset of Shark species, IUCN Red List Status and Usage for Shark's Fin

Note: An effort has been made to highlight the species used in shark's fin, but due to translation issues some species may have been left out. Different species may also be used for shark's fin in different parts of the world.

No remuneration was received from the MPA for this post, but there was a meeting over dinner with a spokesperson of the Association to discuss issues around the Shark's Fin Trade, which was paid for by the Association. The MPA had no control over the editorial stance of this post, but it provided factual information on the species used in the trade.

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