AI System Monitors Whales in San Francisco Bay to Reduce Ship Strikes

A new AI-powered detection network called WhaleSpotter began operating this week in San Francisco Bay. The system scans the water around the clock for whale blows and heat signatures up to two nautical miles away. Ferries, cargo ships and tankers move through the bay daily. The network sends alerts to mariners so they can slow down or change course when whales are nearby.

Thomas Hall, director of operations for San Francisco Bay Ferry, said the alerts will let operators adjust routes well before they approach whales. The system will also collect data on whale locations to help adjust ferry routes during whale season.

One thermal camera is mounted on Angel Island. A second camera will be installed on a ferry traveling between San Francisco and Vallejo. Researchers plan to add cameras on the Golden Gate Bridge and Alcatraz to expand coverage.

Last year, 21 dead gray whales were found in the wider Bay Area, the highest number in 25 years, according to The Marine Mammal Center. At least 40 percent of those deaths were attributed to ship strikes. At least 10 more gray whales have died in the Bay Area so far this year.

Scientists say the actual number of deaths is likely higher because many carcasses sink or drift out to sea. Gray whale numbers in the eastern North Pacific have fallen by half over the past decade, leaving roughly 13,000 animals.

Warming ocean temperatures have altered gray whale feeding patterns in the Arctic, according to a 2023 study in Science. Many whales now enter San Francisco Bay and remain in high-traffic areas between Angel Island, Alcatraz and Treasure Island. Humpback whales face additional risks from crab fishing gear.

Thirty-six whales were confirmed entangled off the West Coast in 2024, the highest number since 2018, according to NOAA. California approved commercial use of ropeless pop-up crab gear this spring to reduce entanglement. Rachel Rhodes, a project scientist at the Benioff Ocean Science Laboratory, said the system is the first to combine land-based and vessel-mounted detections with official mariner alerts.