The Dorsal Fin

SeaWeb.org is featuring a commentary on the scientific integrity of the global shark fin trade by fisheries science researcher Shelly Clarke. Statistics from Clarke’s research on the shark fin trade are often cited when it comes to the estimated number of shark killed each year for commercial markets.

Clarke points out that her best estimate in 2000 was that 38 million sharks per year were being traded worldwide through fin markets, but that the range could be anywhere from 26 million to 73 million. She also points out that many conservation organizations cite that commercial fishing operations kill millions of sharks each year but rarely is her best estimate of 38 million used. Rather, the figures of 73 million (her top-end estimate) or 100 million are used instead.

The 100 million statistic was initially published in a 1997 Time magazine article. The article titled “Under Attack” stated that “30 to 100 million” sharks were harvested each year for their meat, fins, jaws, hides, and internal organs. However, Clarke says she can find “no scientific basis” for the figure.

Clarke goes on to say that her own figures are often misquoted as representing the number of sharks “killed for their fins” or “finned alive.” She notes that no one actually knows how many sharks are killed for their fins or are finned alive and dumped back into the ocean, because the data simply is not available.

When bringing up the question of why the actual number is important, Clarke offers that misuse or “selective and slanted” use of information devalues the impartial work done by researchers to obtain the data. She also warns that misrepresentation and exaggeration of facts can undermine and discredit otherwise worthwhile shark conservation efforts. Additionally, Clarke points out the accurate catch numbers are needed in order to properly manage long-term shark population sustainability.

Clarke finishes her commentary with some guidelines to being a better “science consumer.”

To read Clarke’s commentary in its entirety, head on over to SeaWeb.org.

An estimated 26 million to 73 million sharks are killed annually for commercial markets, research shows.

It seems the magic number of 100 million sharks killed each year gets quite a bit of use in the world of shark conservation, but is there any actual data to support this number? At least one commenter on this blog has called the number into question, which led met to start looking into the basis for the 100 million “statistic.” Other shark conservation-minded bloggers including Shark Diver’s Underwater Thrills and Luke Tipple have called the 100 million number into question this year, due to a lack of a scientific basis for the number. Despite the lack of any hard data to support the number it is widely used and accepted in the media and in many conservation efforts.

Research conducted by Shelley Clarke estimated the global number of sharks killed annually at 26 million to 73 million. Clarke’s Global Estimates of Shark Catches using Trade Records from Commercial Markets journal article published in 2006 in the Ecology Papers Vol 9 Issue 10 follows a generally accepted scientific methodology and is backed up by solid research.

While “26-73 million” might not roll off the tongue quite as easily as “100 million,” there is data to support the former, while there seems to be no solid data supporting the latter. Considering that I make a point of calling attention to instances of misrepresentation and misinformation in the media with this blog, I think it’s important to point out that the use of the 100 million number is not based on any specific scientific evidence, and I would encourage shark conservationists to reference the global estimates from Clarke’s research. At the end of the day, even the low-end estimate, from Clarke’s study, of 26 million is still alarming number of sharks being plucked from the ocean.

The other lesson to be learned from the lack of scientific data to back up the claim of 100 million sharks killed per year, is that opportunistic filmmakers will use the baseless number as springboard to devalue the entire shark conservation effort, as can be seen in the video below.

The gentlemen in the video have a point when it comes to the magic “100 million” number (and the “90% of the species” statistic), but nowhere in the video do you hear mention of the estimates from Clarke’s study, which would be far less disputable.

When it comes to shark conservation efforts, I recommend sticking with data that can be backed up by science. There’s already enough conjecture and flat-out misinformation out there without shark conservationists adding to it (as a couple of the people in the video above do a fine job in displaying).