Back in mid-January, news and social media sites along the East Coast were buzzing with news of Mary Lee, a 3,456-pound great white shark that was tagged by the research organization OCEARCH off of Cape Cod last September. After being tagged, Mary Lee headed south where she excited many seaside communities with some very close swim-bys. At one point, she came within 200 yards of the beach in Jacksonville, FL, prompting OCEARCH officials to request that local police clear the waters until she moved on.

Two days after her close-to-shore encounter in Florida, however, Mary Lee stunned researchers by starting a northern journey on January 10, which in just 20 days had her knocking on the door of the Hamptons off the eastern end of Long Island, NY, before heading even further up the coast for a visit to Cape Cod, MA and a substantial run toward Nova Scotia. It was previously believed that great white sharks spent the winter months in more southern waters, only returning to New England in the late spring/early summer. As of late February, Mary Lee was swimming in the vicinity of Bermuda, having circled back to the southeast while heading further offshore.

GROUNDBREAKING DATA
Sightings of great white sharks have been reported with increasing regularity along the coast of Cape Cod in recent years and this uptick has not gone unnoticed by the scientific community. It should come as little surprise then, that scientists have been tracking the sharks in these waters, trying to gain a better understanding of their movements and habits. In 2009, Dr. Greg Skomal, from the Massachusetts Division of Marine Fisheries, began a great white shark tagging program using PSATs (Pop-up Satellite Archival Tags). Once attached to a shark, these tags archive data such as depth, temperature and light levels. After a pre-established amount of time, the tag will release from the shark, allowing it to float to the surface. Once at the surface, the tag transmits all the data it has collected to a satellite, which relays the data to researchers for analysis. Information collected in this manner provides a valuable look into the life of any specific shark that has been tagged. Since 2009, Dr. Skomal and his team have deployed approximately 30 PSATs.

In 2012, Chris Fischer, from OCEARCH, teamed with Dr. Skomal to deploy SPOT (Smart Position and Temperature) tags on East Coast sharks. Unlike PSATs, SPOTs supply researchers with real-time data. The SPOT is placed on the shark’s dorsal fin and when the tag breaks the surface of the water, it transmits data such as location, temperature and water salinity to a satellite that forwards the info to the research team. Since the non- magnetic tags are relatively small, transmit at a frequency far outside the fish’s hearing range, only transmit when the tags break the surface, and are positioned in the dorsal fin well away from the main sensory structures around the head, it is unlikely the tags in any way affect a shark’s ability to navigate. The sharks are all tagged legally and permits are required to perform such measures.

FULL OF SURPRISES
"The thing that is really neat about this program,” said Fischer, is that we are getting baseline information, the first of its kind, about these tagged sharks. Even better, because the data is gathered and presented in ‘real time,’ the public gets to see it at the same time as researchers with PhDs. So this program is really is bringing the scientific community together with the general public and letting everyone be involved.”

In the case of Mary Lee and her unexpected wanderings, Fischer said “this shark has blown his mind. “We weren’t really surprised that she covered a lot of ground,” he explained, noting that great whites tagged in the Pacific and off of Australia regularly travel 4,000 to 5,000 miles a year and have been known to cover 80 miles a day for several weeks at a time."