Tagging Great White Sharks In Cape Cod
Captain Brett McBride holds the line steady as the lifts raises him and the great white shark out of the water.Caroline Nurse/OCEARCH
For the first time ever in North Atlantic waters, a great white shark has been tagged and released with fine motion sensors, capable of revealing unprecedented information about one of the most misunderstood creatures on the planet.
The tagging expedition is led by OCEARCH, a non-profit organization that provides support for researchers looking to gather data on the biology and health of sharks, as well as their life history and migration.
For this project, research is being carried out by Dr. Greg Skomal of the Massachusetts Division of Marine Fisheries and a team of scientists, including Mote Marine Lab?s Dr. Robert (Bob) Hueter ? the Director for the National Center for Shark Research.
Captain Brett McBride alongside "Mary Lee."Caroline Nurse/OCEARCH
Since the expedition began on September 3 in the waters of Cape Cod, two great white sharks have been successfully tagged and released. The first, nicknamed ?Genie? after Mote's founding director, Dr. Eugenie Clark, measured about 15 feet and weighed an estimated 2500 pounds.
The second shark was even bigger: ?Mary Lee,? a 16 foot long, fully mature shark weighing close to 3500 pounds.
Chris Fischer, the OCEARCH expedition leader, named the shark after his mother.
His team is responsible for finding, catching, and hauling in the shark, while the scientists take samples and affix their tags.
The top tag marks the shark's geographic location, while the bottom tag is the pop-off accelerometer.Caroline Nurse/OCEARCH
One of the tags is an accelerometer, a fine motion sensor designed to record every tail beat and tilt of a shark?s body using the same motion-sensing technology found in smart phones and the Nintendo Wii.
The accelerometer breaks off and floats to the surface after a day being attached to the shark. The information contained within is not only new knowledge of how great white sharks move, but also shows how well the shark recovered from being tagged.
So far, both sharks have shown no ill effects whatsoever.
In addition to the accelerometer, they are tagged with a satellite transmitter that can send scientists real-time updates on the shark?s geographic location.
The public can follow the global shark tracker here.
Looks like they found a big enough boat
As could be expected, tagging great white sharks is no easy task.
At this angle you can get an idea how big this shark really is.Mike Esterbrook/OCEARCH
First, a shark has to be caught. The crew uses a 27/0 Mustad hook, designed to handle 4,400 pounds of force. Once a great white takes the bait and is hooked, the OCEARCH team attaches floating balloons to the line that slide down to the shark, keeping their catch close to the surface.
They then bring the shark towards the M/V OCEARCH a unique 126-foot vessel equipped with a custom 75,000 hydraulic lift and research platform, formerly a Bering Sea crabber.
Once they get the shark to the lift, that's where the work really begins: the platform raises the shark out of the water, allowing the crew to walk out and tag its fins.
The OCEARCH crew and scientists work quickly to get the shark tagged and released safe and sound.Mike Esterbrook/OCEARCH
Water is fed constantly through the shark?s gills to keep it alive, meaning crew members have to get within inches of 3,000 razor sheep teeth - no sedatives of any kind are used.
All of this may sound like too much of a risk, but OCEARCH have been catching sharks for research purposes since 2007. What is learned is worth the effort, in Fischer?s eyes, especially for great white sharks.
?These sharks are a 400-million-year-old secret. We don?t know where they are breeding, feeding or giving birth,? said the expedition leader about the project. ?What we do is provide the best scientists access to these sharks to gather information and help demystify the life of Jaws.
Water is constantly fed through the shark's mouth and gills throughout the tagging process.Mike Esterbrook/OCEARCH
?Our goal is to increase knowledge of these animals to ensure that they have a robust future. Conservation decisions should be driven by data rather than emotion.?
Tagging and monitoring great white sharks this way will allow Dr. Skomal and his team of scientists to learn:
- Reproductive behavior, including where and when great whites mate.
- Juvenile behavior and their relation to nursery grounds.
- How season and stage of life affect individual movements.
- Adult female behavior.
- Identification of additional coastal sites.
Having more knowledge of sharks helps authorities make the right conservational decisions to protect them.
Sharks are an apex predator that is crucial to maintaining balance in the world's oceans. Their loss would lead to a catastrophic domino effect throughout the food web.