From Shark Teeth To Shark Cage: some interesting items in the news

As we approach Discovery's Shark Week, here are a couple of interesting shark items that have been traveling the Internet. First, a study by chemists from the University of Duisburg-Essen found that the teeth of mako sharks and tiger sharks contain the mineral fluoroapatite (fluorinated calcium phosphate). Humans' and other mammals' teeth contain an inorganic, bone-like compound, hydroxyapatite. as we all known from or fluoride toothpaste, mouthwash, and water, there is an advantage to having some fluoride protecting our chompers. “In order to make teeth more acid resistant, toothpaste often contains fluoride,” Matthias Epple, a professor of inorganic chemistry at the University of Duisburg-Essen, told Discovery News. “In the surface ofhuman teeth after brushing, a small amount — much less than 1 percent — of hydroxide is exchanged by fluoride. In contrast,(the surface of) shark teeth contains 100 percent fluoride. In principle, sharks should not suffer from caries. As they live in water and as they change their teeth
regularly, dental protection should not be a problem for sharks.” So, sharks have built-in cavity protection. And, as the professor mentioned, they replace their teeth regularly. A shark can contain as many as several hundred teeth in it's jaw at any one time, with rows of fresh new teeth ready to come to the fore as older teeth are pushed out. Which brings me to the second interesting shark item. Many of you have seen images of the white sharks at Seal Beach, South Africa leaping out of the water attempting to either bite down on an unsuspecting seal - or a seal decoy placed in the water by crews hoping to grab some spectacular video or still photos. South Africa's Chris Fallows has built a respected career out of documenting white sharks going airborne with videos like the "Air Jaws" series and some amazing photographs. Australia's The Daily Telegraph ran a brief article on Seal Beach with photographer Dan Callister taking his own memorable photographs of airborne white sharks. As dramatic as his shots were, what caught my eye in several rapid-fire images of a shark grabbing a seal decoy was the clear evidence

of the shark shedding a tooth. You can see it airborne in the image below. Lastly, for those of you who have ever wondered what it would be like to see a great white shark up close, but decided you had to be an experienced diver or half crazy, Kevin Richberg wrote in The Huffington Post's Travel Blogs his experiences cage diving in Australia as part of his 30 Postcards Project. What caught my attention was how he described the experience. When doing any public speaking about white sharks, I often recall the word that first came to mind when I saw my first great white shark. Serene. There is a calm majesty to these animals; not a frantic, teeth gnashing demeanor at all. And that was exactly how Richberg saw it. "What surprised me was that following the initial excitement of seeing the sharks up close, my mood turned quite quickly to being calm and peaceful. I know you're probably thinking that 'peaceful' is the last word you'd use to describe a great white shark encounter, but for me it was true."Source: RTSea

Read More........→August 09, 2012

Smartphones and Sharks: video game technology is aiding shark research

RTSea: There you are, smartphone in hand, ready to engage in supersonic aerial combat. Or for more exercise, you stand in front of your television, clenching your game controller tightly, ready to play world-class tennis - game, set, match. Many of today's video games are aided by the use of accelerometers - electronic sensors that can recognize motion in a multitude of directions. Accelerometers have worked their way from aerospace and high-tech machinery applications to today's consumer electronics. And now they are adding another dimension to the study of sharks. At the Mote Marine Laboratory in Sarasota, Florida, Dr. Nick Whitney, head of Mote's Behavioral Ecology and Physiology Program, has been utilizing accelerometers in shark tags to advance the study of shark movements. "These accelerometer tags use the same technology found in iPhone[s] and Wii. It can actually tell us what an animal is physically doing, what their body movements are and what their body posture is," said Whitney. Correlating the data on shark movements with laboratory studies on oxygen consumption, Whitney is better able to make estimations of shark behavior, such as during mating or, in particular, during catch-and-release situations. Whether when promoting catch-and-release to sportfishermen or when catching sharks for scientific tagging and then releasing the shark, the extant to which a shark may be traumatized during the catch and how quickly it recovers is of great importance.  a while to recover?" Whitney questioned, "Do they swim off strongly, doing great? Or does  it take them

There are a wide range of telemetry tags used in shark research. Some are designed for regional behavior, monitoring a shark's depth, speed, and even internal body temperature. With a limited transmitting range, these tags are ideal for monitoring sharks within a shorter range of less than a mile. Dr. Peter Klimley at UC Davis as become one of the acknowledged masters of the art of regional telemetry tags and I have seen them used extensively with the white sharks at Isla Guadalupe, Baja. However, many sharks species are long-distance travelers and this is where "spot" or satellite tags are preferable. These more sophisticated tags record data for much longer periods of time, periodically downloading their data to satellite networks that surround the planet. Dr. Barbara Block, director of theTOPP Program (Tagging of Pelagic Predators), and Dr. Michael Domeier seen in National Geographic'sExpedition: Great White series, often make use of these types of tags, as do many other researchers for a variety of migratory shark species. With accelerometer tags, scientists like Dr. Whitney can get a glimpse of more than where a shark is, but how it's "feeling" as body movements can be correlated to its respiratory functions and overall metabolism at a given moment. Whitney will be soon starting a research study on blacktip sharks utilizing the accelerometer tags. I can't wait for the video game version to come out for my iPhone. Source: RTSea

Read More........→April 08, 2012