Researchers have not known the whereabouts of the shark, known as Katherine, since May 2019. They received a weak signal from her tracking tag in April this year, but have only now received strong enough data to confirm her identity and location.
Katherine was tagged by marine tracking organization OCEARCH in August 2013 and was followed closely for the following five years. Her movements have helped researchers better understand how female white sharks move around the North Atlantic, potentially including during three cycles of pregnancy, OCEARCH said.
The nonprofit tracks great whites by fitting them with devices that “ping” when a shark breaches the surface, sending the team location data via satellite. These devices normally last for about five years and after Katherine’s tracker failed to ping for around a year, it was thought she would not be heard from again.
However, in April a short and inconclusive ping, known as a “z-ping”, came from her tracker. OCEARCH said the shark’s device appeared to have sent out a signal, but not for long enough for it to be confirmed that it was her.
“Basically the [tracker] sends a signal to the satellite, but it is not strong enough to communicate all of the data needed to get a location for the animal,” the organization said in a statement.
On October 31, several strong signals were recorded from Katherine’s tracker, putting her in the deep North Atlantic, hundreds of miles from the U.S. east coast.
“This is a record for our Atlantic SPOT-tags, that normally only send white shark data to us for about five years.” Bryan Franks, who is Assistant Professor of Biology/Marine Science Jacksonville University and works with OCEARCH, said in a statement. “Katharine pinged in multiple times yesterday, confirming it was not a fluke.”
OCEARCH said it was “very unusual” to get data back for a shark over such a long period and that Katherine will provide a valuable insight into the lives of other great whites in the region.
“Katharine showed movement patterns indicative of being a reproductively mature female [white shark] with trips during some winters out into the open ocean,” the OCEARCH statement said. “Her tracks over the past seven years up and down the coast from Cape Cod to Florida and with long forays to the Grand Banks of Newfoundland, the eastern Gulf of Mexico, and the offshore Atlantic, may cover the movements of two or three cycles of pregnancy and birth of her pups.
“She has already provided an incredible dataset with more than 1,700 locations, covering 37,000 miles of ocean since the day she was tagged. It will be fascinating to see where her next moves may be.”
When she was tagged, Katherine was a sub-adult measuring 14 feet and two inches in length. It is thought that since then she could have grown considerably.
“It’s been seven years. One of the things we don’t understand is the growth rate when they get to this size,” OCEARCH founder Chris Fischer told the Miami Herald in April.
“She’ll be bigger, significantly bigger and in particular, she’s much, much girthier. When they get over 12 feet, they begin to grow girth and body weight. The volume grows quite a bit. She’s probably a very robust, mature female white shark in her productive prime.”
