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.

They really aren't the same year. I promise.

ABC News’, Shark Attacks Rise Worldwide But Drop In the U.S., wouldn’t exactly serve as a benchmark for statistical analysis on annual shark attack incidents. The article attributes a “rise” in global attacks to comparisons of reported attacks from 2008 (60) and 2009 (61). It also seems that the report can’t even distinguish between the 2009 and 2010 incidents, as evidence by the follow excerpt…

“In 2009, there were 61 total shark attacks, five of them fatal, including a 38 year old kiteboarder killed off the Florida coast last month.” – ABC News

Admittedly, I’ve been known to lose track of what day it is. However, I’m fairly certain that 2009 attacks would not include incidents from “last month,” which was February, 2010.

The article also goes on to mention a drop in U.S. attacks. This observation is also based solely on comparisons between overall incident reports between 2008 and 2009. George Burgess offers up a theory on reasons for this “drop,” although the article is polite enough to note that Burgess’ theory (much like the rest of the article) is “based on little scientific evidence.”

According to the news section at the Shark Research Committee on July 11, 2009 Brian Hovnanian was involved in an “unprovoked shark attack,” by definition, at least. According to the article an unprovoked attack is defined by “any physical contact between a shark and human, or piece of equipment being utilized by a human, without any know provocative action by the subject which might cause the shark to strike out.”

According to the report, Hovnanian was stand-up paddleboarding when a 5′ shark with a gray back and white underside bumped into his board, hit his calf, and caused him to fall onto the shark and the board. The shark then slid back into the water and swam off.

While I understand the reasoning behind defining an unprovoked shark attack to not necessarily require a victim being bitten, it seems a bit of a stretch to refer to this as an “attack.” Yes, I know that “technically” it meets the criteria of the definition given by the Shark Research Committee, but based on the article it sounds like the shark might have accidentally bumped into the board and ended up on top of it. I’m no expert, but it’s hard to imagine a 5′ shark mistaking a stand-up paddleboard for food and making a bid to attack it from below. Reading a report like this and seeing it deemed as an authenticated attack makes me wonder if shark attack statistics might be over-inflated with similar encounters.