Tagged scientific evidence

100 million sharks killed each year? Research vs. “magic numbers”

According to research published in 2006, an estimated 26 million to 73 million sharks are killed annually for commercial markets. While this number differs from the 100 million figure that is widely used in the media, it is based on scientific research, which still indicates that tens of millions of sharks are killed annually.
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).