A gray whale found near San Francisco’s Pier 80 died from injuries consistent with a vessel strike, according to the Marine Mammal Center. This marks the 13th gray whale mortality in the Bay Area this year. Scientists report that more whales are lingering in the busy shipping lanes of San Francisco Bay, increasing the risk of fatal collisions with maritime traffic.
Why are gray whales lingering in San Francisco Bay?
Gray whales typically migrate 12,000 miles between Mexican breeding lagoons and Arctic feeding grounds. However, data from the Marine Mammal Center indicates a sharp increase in whales entering the bay since 2018. Researchers suggest these animals use the warmer, shallower waters of the bay to rest and forage, a behavior shift that places them directly in the path of cargo ships, ferries, and recreational boats traversing the Golden Gate Strait.
A study published in Frontiers in Marine Science estimated that at least 18% of gray whales spotted entering the bay between 2018 and 2025 did not survive their time in the region. Experts believe the actual mortality rate is likely higher, as many carcasses sink or drift out to sea before they can be documented.
How does the new AI-assisted detection system work?
To mitigate the risk of ship strikes, researchers from the Benioff Ocean Science Laboratory, the U.S. Coast Guard, and the Marine Mammal Center have deployed a thermal camera system. According to the Benioff Ocean Science Laboratory, these cameras detect whale blows and heat signatures in real-time. The goal is to alert mariners so they can reduce vessel speed or adjust their course when whales are detected in high-traffic corridors.
Current deployment status
- Angel Island: The first thermal camera is active at a Coast Guard station, monitoring the area between Treasure Island and the Bay Bridge.
- San Francisco Bay Ferry: A second system is planned for installation on the MV Lyra, a ferry operating between Vallejo and downtown San Francisco.
What are the primary causes of whale mortality in the region?
The Marine Mammal Center classifies gray whale deaths based on necropsy findings and observational data. Of the 13 deaths recorded in the Bay Area this year, the causes vary significantly:
| Cause | Count |
|---|---|
| Suspected Vessel Strike | 4 |
| Undetermined/No Necropsy | 6 |
| Necropsy Pending | 2 |
| Suspected Orca Predation | 1 |
Frequently Asked Questions
Why is it difficult for ships to avoid whales?
According to researchers, gray whales surface low in the water, making them hard to spot. Combined with heavy traffic and visibility challenges like fog, mariners have limited windows to adjust course.
Are there protocols for ferries to avoid whales?
Yes. SF Bay Ferry Executive Director Seamus Murphy stated that the agency is implementing protection protocols, including route adjustments, speed reductions, and continuous monitoring to ensure safety when whales are present.
What should I do if I see a dead or injured whale?
Report sightings immediately to the Marine Mammal Center or local wildlife authorities. Do not approach the animal, as it may be diseased or pose a safety risk.
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