SAN FRANCISCO BAY — Researchers have recorded 16 gray whales in San Francisco Bay this year, seven of which have died. Necropsies have confirmed ship strikes as the cause of death for some of these gray whales.
The U.S. Coast Guard and conservation groups are utilizing thermal imaging and artificial intelligence (AI) technology to detect whales and broadcast alerts to vessels. Thermal imaging cameras, installed on an island, identify heat signatures from whale exhalations. An AI system and human reviewers verify these whale detections from the camera system before the Coast Guard uses the data to issue location alerts to vessels via radio.
Gary Reed, Director of Vessel Traffic Service San Francisco for the U.S. Coast Guard, said, "We want the word to get out. We want people to know there are whales in a particular location so they don't encounter them." Reed said, "Now with this new technology, it'll show us whales at night, so we can identify them and notify traffic." Participation in the whale avoidance alert system is voluntary for commercial vessels.
Kathi George, Director of Cetacean Conservation Biology at the Marine Mammal Center, said, "She died from injuries due to blunt force trauma from vessel strike." Personnel from the Marine Mammal Center and the California Academy of Sciences performed necropsies on deceased whales. George also noted increased instances of undernourished whales washing ashore in California and the Pacific Northwest in recent years. "These whales are hungry. We think they're stopping at different areas along their route to find sources of food, and San Francisco Bay has become one of those hotspots," George said.
Gray whales migrate annually between Baja California, Mexico, and Arctic waters. Arctic sea ice loss has reduced populations of the small crustaceans that they consume, and they require more than one ton of prey per day during summer feeding periods. The North Pacific population is approximately 13,000 and has decreased by 50 percent over the past decade. Last year, 22 deaths were recorded in the San Francisco Bay Area.
Douglas McCauley, Director of the Benioff Ocean Science Laboratory at the University of California Santa Barbara, stated, "We're looking at a moment for gray whales where every whale that comes in and goes out of the bay matters for population. So even though this is just one piece of the problem, it's a piece that we want to solve, can solve." An additional thermal camera is being installed on a local ferry, and operators for two local ferry companies adjust vessel speed or route when whales are present. Detected whale positions are published on the WhaleSafe website. McCauley said, "I'm really optimistic that this is one of those solutions where the community comes together, and the community solves it, but we'll see."