Tracking Great White Sharks: researcher reconsiders a controversial technique

The first shark I ever filmed professionally, to this day, probably remains as my all-time favorite: the great white shark. There are certainly sharks that can rival its beauty. And I have had my adrenaline pumping while swimming in the midst of other sharks in a frenzy - something you don't see with white sharks. But there is something so overwhelmingly magnificent when I am in the presence of a great white, that it still takes my breath away (or maybe I'm just trying not to spook the shark with my bubbles).

Because of that special allure, I have always been interested in their survival and the research and conservation efforts of others to solve the mysteries regarding their lifestyle that still exist today. As those mysteries are slowly unraveled, we will be better educated as to how best to manage and protect the remaining white shark populations, which are in perilous decline.

Over the past year, there has been quite a controversy within the shark research and, particularly, the shark advocate community regarding the research methods of Dr. Michael Domeier - techniques that were featured in the National Geographic television series Operation: Great White and can be seen in Nat Geo's new series Shark Men. Domeier devised a method that entailed hooking a great white, tiring it out to where it could be pulled up onto a large boat platform and hauled out of the water. Then, with only a few minutes available to Domeier's team, blood samples and measurements were taken and, most importantly, a long-range, long-term satellite or SPOT (Smart Positioning and Temperature) tag was bolted to the shark's dorsal fin. The shark was then released and tracking of the shark's position would begin in the hopes of determining more precisely what the migration patterns were of these animals.

From the start, there were questions as to whether this particular technique Domeier had devised was harmful to the sharks. It certainly wasn't a minor procedure and appeared fraught with animal trauma from the moment the shark was hooked to when it was dragged aboard to its final release. I, for one, had expressed concern that the method seemed overly complicated - a kind of Rube Goldberg attempt - and one that was perhaps better suited for the making of a dramatic television show.

There were some shark researchers who had expressed both concern over the method of capture and the quality of the data. But the scientific and academic community is a small and tightly-knit world and so opinions were, for the most part, somewhat muted.

However, the online world of shark advocates had a field day with Domeier, particularly with one horrendously botched attempt that left a white shark, named "Junior", with a large portion of the hook lodged deep in its throat. Recently, pictures of that shark have emerged one year after its capture and they show a noticeably emaciated shark with severe wounds that may or not be a result of the bungled tagging episode. The simmering cauldron of online opinion once again went into full boil.

So, what is the latest in this controversial saga? With National Geographic Channel's Shark Men about to air, what can we expect from Dr. Domeier and his white shark research? Well, according to MSNBC, Domeier is in the process of retooling his research techniques. While still defending his capture methods, he is not pleased with the tags themselves and how they are attached. These SPOT tags are rather large and when attached to the shark's dorsal fin, can apparently cause deformation or damage. Domeier is investigating techniques for attaching SPOT tags that would minimize any possible damage. To better focus on this problem, he has chosen not to participate in the television series. From a crisis communications/PR perspective, it's also not a bad idea to take yourself out of the limelight for a while when surrounded by controversy.

Researchers are often faced with difficult decisions regarding the methods by which they gather data, the cost to the subject in question, and how much public media exposure can be advantageous in securing funding or possibly setting you up for intense scrutiny and even ridicule. I would hope that technology would prevail and powerful, long-lasting tags - much smaller and lighter in design - could be developed which would negate the need for such elaborate capture methods as Dr. Domeier felt compelled to employ.

We owe the sharks that much. Even a 16-foot, 3,000 pound great white shark deserves a little tenderness now and then.

Read MSNBC's article on the Domeier controversy.

Sharks on the Right Path: research indicates predators know where they're going

Researchers continue to learn more about the movement of sharks, particularly their ability to navigate along deliberate paths as opposed to random, meandering movements. Much attention has been paid in recent years to the incredible long-distance migrations that many species of shark undertake. But scientists with the Florida Museum of Natural History focused their attention on shorter distances; in essence, how and where the sharks traveled over several days or weeks as opposed to many months. What they found was that sharks at times appear to know exactly where they are going.

The Florida researchers tracked the movements of tiger, thresher, and blacktip reef sharks, and their results, recently published in the Journal of Animal Ecology, showed that the sharks would often exhibit random movements or "walks." However, there were plenty of times when the sharks, particularly the tigers, would demonstrate very directional movement behavior. The tiger sharks appeared to be the best at pursuing these directed walks, covering as much as 30 miles in a singular direction and even traveling several miles to a very specific point underwater.

Yannis Papastamatiou, co-author of the study, said, "Our research shows that, at times, tiger sharks and thresher sharks use highly directed walks to swim to specific locations. Simply put, they know where they are going.

Many people could walk to a known destination 3.7 to five miles away, but imagine doing it in deep water and at night.

As anyone who dives knows, finding your way around underwater without a compass is very difficult, but this is what we found tiger sharks could do."

As a diver, I can attest as to how difficult visual navigation can be underwater. Rock formations that appear one way as you move in a particular direction can look completely different when approached from the reverse direction or different angle. But with a full range of sensory capabilities far beyond that of man, using visual cues combined with other sensory input like temperature, currents, or even the magnetic fields of the earth could make it simply all in a day's work for a shark.

In June of last year, I wrote about similar research studying a variety of pelagic - or open-ocean - predators like swordfish, tuna, and sharks. In this study, the researchers were looking for certain mathematical patterns: Brownian walks for so-called random movements, and Levy flights for more directional straight movements. One of the researchers noted that the use of straight line movements as opposed to random may have been initiated due to the availability of food.

Lévy behavior showed up more often in waters where plankton, fish and other food was scarce. In regions with plentiful food, random motion dominated. This observation, says theoretical physicist Gandhimohan Viswanathan, fits with earlier suggestions that 'animals may use a Lévy flight motion to improve their chances of finding prey.'”

Whether motivated by food or some other impulse or whether or not supported by a keen sense of visual direction or some other ability (all questions to be answered with future research), it can be said that in a challenging environment like the ocean, sharks are being shown to demonstrate some highly intelligent movement behaviors, perhaps relying on some "cognitive maps" lodged somewhere deep within their brains.

Read about shark movements in U.K.'s Mail Online.
Read about Brownian walks and Levy flights in RTSea Blog.