Conservation

Shark Wranglers Tag 2,500-Pound Great White Shark

The crew on OCEARCH recently tagged a massive great white shark with a fine-scale motion sensor — a first for scientists. The female great white, which weighed more than 2,500 pounds and measured nearly 15 feet long, was tagged and released on September 13 during an expedition off of Chatham, Massachusetts. The project is a group effort, led by Chris Fischer’s OCEARCH and includes researchers from the Massachusetts Division of Marine Fisheries, Mote Marine Laboratory and other collaborators.

The great white shark was tagged off of the M/V Ocearch, a unique ship, which uses a custom lift to raise giant great whites out of the water so researchers can collect biological samples, apply tracking tags that and then return the sharks to the wild. The OCEARCH crew and their ship are featured in the show “Shark Wranglers” on HISTORY (formerly The History Channel).

The 2,500-pound shark is the first great white to be caught and released by OCEARCH in the North Atlantic — and she has already made scientific history. The fish is the only Atlantic great white ever tagged with a satellite transmitter that can send scientists real-time updates on her geographic location. She is also the first great white tagged with an accelerometer — a motion sensor designed to record her every tail beat and tilt of her body using the same motion-sensing technology found in smart phones and the Nintendo Wii.

Dr. Robert Hueter, Director of the National Center for Shark Research at Mote, is coordinating Mote’s involvement in the project and was on the M/V Ocearch during the first week of the expedition, when bad weather allowed for only one day of fieldwork.

“It was unbelievable putting it on,” said Dr. Nick Whitney, who deployed the first accelerometers on several coastal sharks and other species — but never on anything so massive. “It was nighttime and I was working on the dark side of the shark — she was so enormous she blocked out the lights from the boat.”

The shark was fitted with an acoustic transmitter that will provide data on her position by sending a signal to receivers placed in coastal waters of the eastern United States, and she was fitted with a satellite tag for real-time tracking by Dr. Gregory Skomal, Senior Scientist with the Massachusetts Division of Marine Fisheries.

Skomal, the Scientific Leader of the current expedition, nicknamed the shark “Genie” to honor Dr. Eugenie Clark, who founded Mote Marine Laboratory in 1955.

The news quickly reached Clark, who turned 90 this year and continues to do research from her office at Mote’s main campus in Sarasota, Florida. “I’m honored, and I’m glad the shark is alive and swimming,” she said. “I’ve seen and dived with many great whites off Australia, and it’s good to hear that one has been tagged off Massachusetts, which is not far from where I was born and raised in New York. I hope this shark will be around a long time, like me.”

shark wranglersGenie the shark swam off looking strong and bearing scientific equipment that should help reveal the life cycles of great whites in new detail. Despite the popular fascination with great whites, many basics about their life history remain unknown; the new tags deployed on Genie will help uncover great-white movement patterns and potentially reveal vital habitats where they mate and give birth.

“This shark may be the most important fish we’ve ever caught in our lives,” said Chris Fischer, Expedition Leader, Founding Chairman of OCEARCH and owner of the M/V Ocearch.

Exciting data have already come in from Mote’s accelerometer, which measured Genie’s every tail beat and body tilt for 10 hours before detaching and floating to the surface, as it was programmed to do.

“We were thrilled,” Whitney said. “The data showed us that she swam off the lift really well. She surprised us by swimming very level. Other sharks we’ve tagged tend to go up and down constantly in the water column, but she was as stable as a 747 jet. She started with frequent tail beats of lower power, and then she resumed a stronger, more typical swimming pattern with more force behind each tail beat. During the last few minutes before the tag came off, she was very active — she might have been swimming in strong currents or chasing prey.”

Shark Wranglers Tag 2,500 Pound Great White Shark

shark wranglersGenie’s real-time satellite tag has been signaling her geographic location since September 14, revealing that she headed south, continuing on past Nantucket. The public can follow her progress at sharks-ocearch.verite.com/.

Attaching multiple tags and gathering several biological samples from the same shark allows scientists to better understand the movement, behavior and physiology of great white sharks, which are considered “Vulnerable” by the International Union for Conservation of Nature and are protected by many national governments, including the U.S. For more information about OCEARCH, visit ocearch.org/expeditionblog/.