Could Shark Teeth Help Scientists Learn about Earth’s Past Climate?
Cameras flash almost every time a big, toothy shark passes in front of visitors through the viewing windows at the Tennessee Aquarium. But guests might not realize that the snaggle-toothed grin of the sand tiger shark could help give scientists a snapshot of what Earth’s climate was like eons ago.
Researchers have discovered that the chemical composition of sharks’ teeth is strongly influenced by water temperature. Certain bonds develop differently in cold water compared to warm water. UCLA’s Dr. Aradhna Tripati and CalTech’s Dr Robert Eagle are attempting to calibrate the carbonate “clumped isotope” thermometer using shark teeth collected in controlled environments like the Tennessee Aquarium. “Initial experiments with shark teeth from different aquarium temperatures show that we can measure the temperature at which the fish lived, to within 1-2oC” Dr. Eagle said. “Our work with Tennessee Aquarium will allow us to go on and examine the water temperatures in which extinct sharks lived from fossil teeth, even millions of years back in time. We also intend to go on and use this technique to investigate the body temperatures of extinct organisms of unknown physiology, such as dinosaurs. ”
Recently, volunteer divers began collecting teeth inside the Aquarium’s Secret Reef exhibit for this study. No dental instruments were required however. Volunteer divers simply used their sharp eyes to collect nearly 100 teeth on the bottom of the exhibit that the sharks had lost.
Sand bar and sand tiger sharks lose teeth almost daily according to senior aquarist Rob Mottice. “Most sharks have seven rows of teeth in each jaw,” Mottice said. “And since they loose a tooth from the front row every 10-14 days, they will literally generate thousands of teeth in their lifetime to replace the lost ones.”
The teeth collected in the Secret Reef will give the scientists a control group of samples from 78 degree water. These will be examined along with shark teeth collected from other Aquariums. “The London Aquarium has offered us teeth at 75 deg. F, and the Monterey Bay Aquarium has offered us some teeth from a tank that is at 65 deg. F,” Dr. Tripati said.
While these researchers are sinking their teeth into solving climate mysteries that may be locked in enamel, the Tennessee Aquarium is hoping everyone sees sharks in a new light because of this project and other knowledge gained about these apex predators.
The Tennessee Aquarium is once again partnering with the Association of Zoos and Aquariums to present sharks in a positive light – as an important part of the natural world worthy of conservation efforts. The Aquarium hopes to build on the popularity of the Discovery Channel’s “Shark Week” August 1st through August 7th by offering shark touch encounters, special dive shows and feature presentations by underwater filmmaker Richard Theiss.
Theiss spent the better part of three years filming great white sharks off the coast of Baja, Mexico. His film, Island of the Great White Shark, documents the ongoing scientific research intended to secure their survival. “These are absolutely magnificent creatures living on a razor’s edge of possible extinction. And there are some very dedicated people working tirelessly to prevent that,” Theiss said.
Aquarium visitors could get a double dose of outstanding great white shark footage. Theiss will show guests the inspiring footage of the huge sharks in the crystal-clear waters off Isla Guadalupe twice on Saturday, August 1st at 11 am and 1 pm. Both showings will be in the River Journey Auditorium and are free with Aquarium admission.
At the IMAX 3D Theater, shark fans will be thrilled at the amazing great white footage seen in Under the Sea 3D. Howard Hall’s crew spent hours underwater to capture spectacular “in your face” 3D scenes off the coast of southern Australia. Hall also emphasizes the need for shark conservation in his film.
Tennessee Aquarium visitors can also show their toothy grins while posing inside the great white shark cage used during the production of “Blue Water, White Death,” the film which inspired Peter Benchley to write the novel, “Jaws.”
Fast facts about sharks:
- Sharks eat about two percent of their body weight per day – slightly less than humans.
- Great white sharks can go three months without eating.
- Sharks become immobile when upside down.
- An estimated 100 million sharks are killed by humans each year.
- Sharks grow slowly, take many years to mature and often reproduce only every other year.
- Sharks have only a few young per litter.
- The United Nations estimates some shark species have declined by as much as 80% in the past decade.
Come prepared for your visit to the Tennessee Aquarium by downloading “Shark Week” activity sheets at www.tnaqua.org . Guests will save $5.00 off each Aquarium/IMAX combo ticket when they present the activity sheet at the ticketing center during “Shark Week” August 1st through August 7th, 2009.
The Tennessee Aquarium inspires wonder and appreciation for the natural world. Admission is $21.95 per adult and $14.95 per child, ages 3-12. Each ticket purchased helps support Aquarium conservation programs. The IMAX® 3D Theater is next door to the Aquarium. Ticket prices are $8.50 per adult and $6.00 per child. Aquarium/IMAX combo tickets are $27.95 for adults and $19.95 for children. Excursions aboard the new River Gorge Explorer depart daily into “Tennessee’s Grand Canyon.” Cruise tickets are $29.00 per adult and $21.50 per child (3-12). Advance tickets may be purchased online at www.tnaqua.org or by phone at 1-800-262-0695. The Aquarium, located on the banks of the Tennessee River in Chattanooga, is a non-profit organization. Open every day except Thanksgiving and Christmas, the Aquarium and IMAX are accessible to people with disabilities.