Nearly 1 in 5 Gray Whales That Enter San Francisco Bay Die There

Researchers tracked gray whales entering San Francisco Bay from 2018 to 2025 and found that about 18% of identified individuals later died there.

Vessel trauma and starvation were the main causes of death, according to necropsies and field observations.

Most whales did not return in later years, suggesting the bay is becoming a risky stopover rather than a reliable habitat.

The study highlights how climate-driven shifts in whale behavior can increase ship-strike risk in crowded waterways and complicate conservation for a declining population.