The Dorsal Fin

Yesterday, Underwater Thrills: Swimming with Sharks a commentary on the need for standardizing protocols for SPOT (Smart Position and Temperature) tagging of breeding-age great white sharks at Isla de Guadalupe. Accompanying the commentary was the video seen below.

It’s hard to argue with the points made over at the Underwater Thrills blog, after watching the video. The seawater hose that is needed for the shark to continue to breathe is all over the place in the video, instead of in the sharks mouth passing water through its gills. Another apparent major fault seen in this video is the lack of proper support for the shark, listed as weighing over 1,000 kg (2,205 lbs) in the video’s information. The coup de grâce for the video occurs when one of the researchers loses balances and ends up flipping off the stern of the research vessel, bouncing off the head of the shark and landing in the water. Fortunately, the individual did not seem to be seriously injured by the fall. The events in this video illustrate the risks to both the humans and the sharks involved in this technique.

While there is little doubt that those involved with SPOT tagging have the intention of helping great white sharks by gaining more knowledge about the species, the risks involved in operations like the one seen in the video seem like they create a potential “more harm than good” scenario. Here’s to hoping that future endeavors involving SPOT tagging can follow a methodology that is safer for both researchers and sharks alike.

Along with stumbling across Blue Sphere Media’s shark finning video, I also checked out some of their other shark footage. For a more positive themed shark video, check out their Realm of the Shark footage from Cocos Island (Costa Rica) and Malpelo Island (Colombia), which includes some great footage of schooling hammerheads.

A pirated version of Blue Sphere Media’s Unnatural Selection – Shark Finning on the Frontier video recently popped up over on YouTube. I hadn’t seen this video before, so I tracked the original down through Blue Sphere Media’s website and their Vimeo channel. The video seen below features some powerful imagery of finned sharks. From a production standpoint, the video gets an A+. Unfortunately, the video suffers from “magic number syndrome” (both the “100 million” and “90% decline” estimates make appearances in the video). The footage in the video alone is enough to make a strong message about shark finning, but when accompanied by “statistics” that have no scientific evidence behind them, the message becomes diluted. The problem of shark finning is real, as evidenced by the footage in the video, so why not use some “real” numbers (not to be confused with the real numbers you learned about in 5th grade during Mrs. Walker’s math class) to accompany this footage?

Warning: Video contains footage of discarded finned shark carcasses and severed shark fins.

According to a press release at Science Daily, research published on January 25, 2009 in the Journal of Heredity shows that long-term survival of shark pups born of virgin mothers is possible. Dr. Kevin Feldheim of The Field Museum, has confirmed through genetic testing that two white-spotted bamboo sharks (Chiloscyllium plagiosum), now five years of age, were born to a virgin female shark. This is the first documented case of multiple shark births to a virgin mother, in which the offspring survived.

Feldheim’s analysis of comparisons between several sections of the genome of the shark pups and the mother shark indicated that all of the genetic material passed on to the pups was from the mother shark. Further analysis of more than a hundred additional regions of the genome, performed by Dr. Paulo Prodöhl and Séan Fitzpatrick of Queen’s University Belfast (Belfast, UK) confirmed Feldheim’s findings and also showed that the pups did not share all of their mother’s genetic material indicating that the shark pups were not “true clones” of their mother.

Scott Tucker, whom I can only describe as the Mr. Rogers (minus the cool puppets like King Friday) of public access wildlife television, was recently interviewed on Connecticut’s WTNH8 about his “Last Blue Shark” program and shark conservation, in general.

Tucker addresses the shark fin industry and the impact that is having on global shark populations. Tucker suggests ways that the audience can contribute to shark conservation efforts. Unfortunately, while discussing the shark fin industry, Tucker not only references the “100 million” magic number but also goes on to claim that 100 million is a conservative estimate and that “they believe it is even more.” While I certainly support Tucker’s good intentions, I believe that using “statistics” that have no scientific research behind them is potentially more harmful to shark conservation efforts than helpful. Within the past few months, the unsubstantiated claim of “100 million shark killed annually” has been used as a platform to discredit shark conservation efforts. In order for conservation efforts to be taken seriously, those promoting these efforts would be better served using the estimate of 26 million to 73 million sharks killed commercially each year, which is backed up by research (Clarke et al. 2006)

In addition to discussing shark finning and promoting conservation awareness, Tucker also plugs his latest episode of Expedition New England, “Last Blue Shark.” Expedition New England is a public access wildlife show which airs throughout Connecticut, as well as a few other localities (including Melbourne, Australia, believe it or not).