Newly deployed system aims to warn ships of whales in their path
An AI-powered monitoring system could save the lives of gray whales that are increasingly taking deadly detours in California’s heavily trafficked San Francisco Bay.
The new technology combines thermal cameras deployed 24 hours a day at different locations in the bay with AI to detect whales up to 7 kilometers away. Once the whale detection is confirmed by scientists, an alert is issued to warn ships in the area to slow down or change course to avoid a collision.
A coalition of ocean scientists, the U.S. Coast Guard, whale tracking experts and local ferry companies unveiled the deployment to the bay on May 19. A camera mounted on a radio tower on Angel Island in the bay will monitor many busy shipping lanes. A second camera will be installed on a passenger ferry that crosses the bay daily, and future additional camera sites could include the Golden Gate Bridge and Alcatraz.
AI-based whale detection technology was the brainchild of researchers at the Woods Hole Oceanographic Institution, or WHOI, in Massachusetts, who then created a company called WhaleSpotter to commercialize the technology. “We wanted to be able to detect whales so far away that it would give mariners time to act,” says Daniel Zitterbart, a physicist at WHOI and chief scientist of WhaleSpotter. This is particularly important for large ships, such as container ships, which have high inertia and cannot change course quickly.
It took about 15 years to develop a reliable whale detection system, Zitterbart says. The water emitted from whale blowholes, or from the bodies of the whales themselves, is warmer than the ambient water by about 2 degrees Celsius. So the researchers used hundreds of thousands of thermal images to train the AI to recognize these relative temperature differences as signifying a whale. Then, if detected, a WhaleSpotter researcher will verify the data to minimize false positives. Once verified, an alert is sent to all nearby ships.
“We want as many deployments as possible, because ultimately that means we have better eyes on the ocean,” Zitterbart says. “Shipping is not going to disappear. We need technology that allows us to use the ocean, but also allows whales to go about their business.”
In 2025, 21 gray whales (Robust Eschrichtius) were found dead in and around San Francisco Bay; Two-fifths of these deaths were due to ship strikes, researchers said. Deaths part of worrying trend that researchers first observed in 2018: Whales increasingly stopped in the bay during their 10,000-mile southward migration from their feeding grounds off the coast of Alaska to their mating grounds near Mexico.
The whales were probably hungry. In the Arctic, they feed on tiny crustaceans called amphipods in ocean sediments; these amphipods, in turn, feed on algae that grow under sea ice. Climate change is rapidly melting sea ice, disrupting the food chain.
Gray whale populations have fallen dramatically, from around 20,500 in 2018 to around 14,500 in 2023. Hundreds of whales have been found stranded along the west coast of North America. Many of them the whales suffered from malnutrition. So, to sustain themselves for the remainder of their migration, they head toward the bay in search of food.
“It’s heartbreaking to see these hungry whales stumbling amidst the hustle and bustle of San Francisco Bay,” Douglas McCauley, a marine ecologist at the University of California, Santa Barbara, said May 19 in a press release. McCauley is the director of UCSB’s Benioff Ocean Science Laboratory, one of the coalition partners that developed and is deploying the new technology. “Every day is a challenge… This new system will save the lives of whales. »
Josephine Slaathaug, a whale biologist at Sonoma State University in Rohnert Park, California, hopes the technology will be “a big step in the right direction to protect whales in San Francisco Bay.”
“I’m cautiously optimistic,” says Slaathaug. “I am very pleased that the issue of ship strikes is being taken seriously.” And it’s particularly encouraging, she adds, to see so many different organizations and partners, including the shipping industry, working together to develop a long-term, science-based solution.
