From National Geographic:

The Shark Men are once again in unfamiliar territory; the Sea of Cortez. This time they have a different agenda; they are chasing Amy. Dr. Domeier believes Amy has come to the Sea of Cortez to give birth. The crew soon finds out that this phenomenal region has much more to teach them. They will go on a journey to find the truth behind the great white shark folklore surrounding this area. As the crew uncovers secrets of the Sea of Cortez; the search for Amy continues.

“Shark Men: Deadly Sea” premieres Sunday at 10pm on the National Geographic Channel.

White sharks observed at the surface were identified by unique markings.

Earlier this year, reports of the results of study which estimated the number of white sharks off central California made headlines. Researchers formulated the estimate after surveying known and unknown white shark specimens, which were observed at the surface. Individual sharks were identified based on each shark’s unique markings.

Dr. Michael Domeier of Marine CSI has recently posted commentary on the methodology used in the above mentioned study. Domeier cites that the study assumed that the sampled white shark population was a closed population. Domeier goes on to say that the long term monitoring of white sharks at Isla de Guadalupe has shown that adult white sharks leave and join the population, which violates the assumption of a closed population.

Additionally, Domeier states that the assumption that individual sharks have an equally probability of being observed has been invalidated by previous research.

Domeier concludes that since estimate was based on “faulty assumptions” the estimate is invalid. He also states that the actual number of white sharks in the respective region is “likely dramatically higher” than the estimate reported in the published study.

Dr. Domeier’s full discussion of this study can be found at the Marine CSI website.

Maybe it’s just me, but I was somewhat taken aback when I saw the photo gallery accompanying the article, Great White! at OutdoorLife.com. According to the article, researchers used "rod-and-reel fishing techniques, modified to accommodate the hefty 4,000-pound great whites, to get the fish into the boat". The article features a photo album with various shots of "landed" white sharks, which appear to have been taken at Isla de Guadalupe. According to the article the sharks were baited with tuna. Once the sharks were hauled on to the boat, blood was drawn for testing and satellite tracking tags were attached to the sharks’ dorsal fins. The gallery ends with the following, "While it’s fishing in every sense of the word, it’s imperative that the sharks are released into the sea unharmed and unstressed."

This is how great white sharks at Isla de Guadlupe look when not pulled out of the water.

While I don’t doubt the good intentions of the researchers, based on the pictures, it clearly doesn’t appear as if the sharks were "unstressed" throughout the experience. Being hooked, landed, and tied down seems like it would be a fairly stressful situation, although I’m not a "shark expert," so don’t quote me on that.

Don’t get me wrong. I understand that the knowledge gained from the research could potentially benefit the species as a whole, but I have to wonder if this approach is really the ideal technique for gathering information about the white sharks at Guadalupe. Having been in the water with some of the sharks in the photos, looking at images of them tied down and out of the water just doesn’t sit right with me.

A documentary on this study will premiere on November 16 on The National Geographic Channel.