Monitoring Great White Sharks off the Coast of San Francisco

Zack Johnson
Zack Johnson

Just a 3-hour boat ride away from the busy San Francisco Fisherman’s Wharf lie several rocky islands - surrounded by some of the world’s most favored great white shark hunting grounds. Every fall, an organization called Shark Stewards leads public education expeditions to the Farallon Islands that introduce students and the general public to marine ecosystems, marine life, and the management challenges of both. David McGuire is the founder of Shark Stewards and leads these trips regularly into what is known as the "Red Triangle."

Getting Up Close to the Ocean's Top Predators

David uses Trident Underwater Drones to provide a unique and unforgettable experience for his guests:

“To me, Trident is an excellent tool to share the diversity and our impact on the ocean, to show how incredible our wildlife is and why it deserves to be protected. It’s really a whole new Farallon experience for me and my guests. It’s always incredible to be out on the water, but it also opens up a whole new dimension under the water.”

David and the Shark Stewards don’t make these trips solely for the guests’ education and enjoyment. They’re simultaneously doing real-time MPA monitoring. On each trip, they collect data using Trident. The footage collected is not only exciting for their guests, but also useful for researchers.

Each trip provides more discoveries and more data. This is especially important in areas like the Farallons, where studying wildlife underwater is extremely difficult.

“It’s a challenging environment out here with rough swells, cold water, and especially around this time of year when the great white sharks are congregating to feed. It’s hard to get work done from a shark cage, but with Trident we can provide data regularly.” 

The most compelling reason that guests take trips with Shark Stewards is the chance to see first-hand evidence of the presence of great white sharks, usually in the form of a “predation event”—the savage slick of blood-red water after a kill—or a rare glimpse of the actual shark itself. Great white sharks are incredibly charismatic, even iconic. They are also a threatened species, and researchers still don't know a lot about them because they are so difficult to observe. On his most recent trip, David deployed Trident into the deeper channel called “shark alley” surrounding the islands. As soon as Trident was in the water, guests and crew members huddled around a monitor streaming live video from the drone, hoping to see a shadow or a fin.

researchers) but showed an interest in Trident, making several exciting close passes. Trident’s detailed video footage showed that the shark didn’t have a tag, but according to David, his many distinct scars and markings were enough to enter him into the Block Lab's database in the Tagging of Pelagic Predators program. “Exploring our sanctuary at the Gulf of the Farallones is a gift of nature....and sometimes you get even more than you ask for.”

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