Forget Shark Week: Researchers tag n' track great whites

Using four different kinds of tracking technology, OCEARCH finds sharks are often closer to shore than you think

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Mary Lee, who was tagged off of Cape Cod, is named after Fischer's mother. "My parents have done so much. I was waiting and waiting for a special shark to name after her and this is truly the most historic and legendary fish I have ever been a part of and it set the tone for Cape Cod," Fischer wrote in an online description of Mary Lee.

Co-Captain Jody Whitworth and master of the Martha's Vinyard OCEARCH team Brett McBride prepare to stabilize a great white shark named Amy. Before taking measurements, blood and securing real-time technology tags, a device is inserted into the shark's mouth to irrigate its gills. (Image: OCEARCH).

How to catch a great white shark

To tag the sharks, the OCEARCH team first goes fishing with a hand-held line tipped with special barbless hook, engineered so it won't injure the animal. The team then brings the shark alongside their 126-foot boat, which has an underwater hydraulic lift that can hoist up to 75,000 pounds. That capacity is needed since the team is not only lifting what could be a one- to two-ton shark but also the water around it.

Once the shark is above the water line, from three to eight scientists get to work on it like a NASCAR pit crew, first placing a wet towel across its eyes to calm it and an irrigator in its mouth so it can breath. The crew then rolls the shark on its side to surgically implant the first tracking tag in its belly.

That device, known as an acoustic tag, is about the size of a Sharpie pen. It can remain in the shark for as long as 10 years and can be "heard" whenever the animal swims to within a quarter to a half mile of underwater buoys that can pick up a radio frequency specific to marine tagging operations. Throughout the world, marine biologists have anchored such buoys, which can record an acoustic tag's unique ID as well as the day and time.

A great white named Garmin was tagged by the OCEARCH team, which picked up his signal after two days and got a good location on him on the third day. Starting in late April, wireless data showed him moving away from Guadalupe Island until mid-July, when he arrived north of the Hawaiian Islands. (Image: OCEARCH).

Once the acoustic tag is in place, the OCEARCH crew rolls the shark back onto its belly and attaches a Smart Position Or Temperature Transmitting (SPOT) device. The SPOT tag is placed high on the shark's dorsal fin because its radio ping can only be received when the shark breaks the surface of the water and a satellite is in position to receive the signal. The longer the fin is out of the water, the more accurate the data. There are six ARGOS global positioning satellites orbiting the earth that can pick up a SPOT tag's ping at any time.

"The ARGOS satellite is only around about every two hours. Then the fin has to stay out of water for minute or two to get a good fix," Whitney said. "It's ridiculous that this works. It's pretty amazing when you look at the map and understand how many fixes we get on these sharks."

The third tag is an accelerometer package, which tracks fine-scale data on the shark's body movement and behavior along with water depth and temperature information. That tag, which is designed to release from the shark after just two days, records more than eight million data points each day, with the information stored to memory. The tag is embedded in a float package that contains a satellite transmitter and a VHF radio tag, which transmits a ping that can be heard over a 10-mile range with a VHF receiver and antenna.

"In this case, the VHF tag allows us to find the needle in the haystack, once the satellite tag tells us where the haystack is," Whitney said.

Although OCEARCH has been using two-day accelerometer tags, the team off Cape Cod is now going for the longest accelerometer track of a shark ever: two weeks of second-by-second behavioral information.

Finally, OCEARCH researchers attach a PSAT archival satellite tag, which records depth, temperature, and light levels (used for geolocation) and stores the data to memory. The tag is programmed to release from the fin anywhere from six months to a year after being attached. It then floats to the surface and processes and summarizes the data for transmission back to researchers via satellite.

"It'd be great if there was one tag to get all the information, but there's not," Berger said.

The researchers have gotten the tagging procedure down to, well, a science. They've perfected the process by performing it on more than 100 sharks -- 67 of them great whites.

To date, the largest great white the team has captured and tagged is an 18-foot, 5,000-pound animal named Apache. Apache currently holds the world record as the largest fish ever caught and released by anyone, Berger said.

For their massive size and ferocious reputation, white sharks actually represent a small minority of shark attacks throughout the world, including the shark attack capital, Florida.

"Florida has more shark incidents than any place in the world, but virtually all of those bites are from small sharks -- black tips and spinner sharks. In fact, I'm not sure of any confirmed white shark attacks there," Whitney said.

Lucas Mearian covers storage, disaster recovery and business continuity, financial services infrastructure and health care IT for Computerworld. Follow Lucas on Twitter at  @lucasmearian or subscribe to Lucas's RSS feed . His e-mail address is

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Copyright © 2013 IDG Communications, Inc.

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