August 28, 2013, 6:14 AM — Meet Mary Lee, a great white shark that's the same weight and nearly the same length as a Buick. And, by the way, you may have been swimming within a few feet of her this past year and not known it.
Since last September, when she received an array of radio, acoustic and satellite tags, Mary Lee has travelled from Massachusetts to Florida, often hugging the coastline so closely that scientists tracking her called beach authorities in Florida to warn them about her. The 16-foot, 3,456-pound shark also headed into open ocean, taking a February vacation off the beaches of Bermuda.
"She was undoubtedly not the only one there. Sharks have probably been doing it for millions of years," said Nick Whitney, a marine biologist with the Mote Marine Laboratories in Sarasota, Fla. "We're learning things that 10 years ago we would have never dreamed we could have learned about these species."
Mary Lee, a 16-foot 3,456-pound great white shark, traversed the East Coast over the past year, at times hugging the shoreline so close as to prompt a warning call from researchers. (Image: OCEARCH).
Whitney, who spoke this week from a research vessel off of Cape Cod, Mass., is part of a team that runs OCEARCH, a non-profit, global shark tracking project that uses four different tagging technologies to create a three-dimensional image of a shark's activities. OCEARCH is hoping to develop successful conservation and management strategies by studying shark habits in more granular detail.
While traditional research has focused on small-scale movements, the data being gathered by OCEARCH offers surprising new information about where sharks go and what they do. That's where the tracking technology is crucial.
A dorsal fin tag attached by OCEARCH uses a satellite to track a shark's position each time it breaks the surface. Other tags include an RFID implant whose ping is picked up whenever the shark passes a special, underwater buoy; an accelerometer, similar to the technology used in an iPhone or Nintendo Wii, that detects up or down movement; and a Pop-off Satellite Archive Tag (PSAT), which acts as a general archive, recording average water depth, temperature and light levels.
"On average, we're collecting 100 data points every second -- 8.5 million data points per day. It's just phenomenal," Whitney said. "Second by second, we can pick up every tail beat and change in posture."
One of the surprises the tracking data revealed is that white sharks don't always stick to cold water, as previously thought. Some even venture into the Gulf of Mexico during the summer.