The majestic gray whales of the Eastern North Pacific are facing another alarming die-off, and marine scientists are scrambling to understand why. At least 70 gray whales have died since the beginning of 2025—many in the shallow lagoons of Baja California, Mexico, where these creatures have migrated for generations to breed, nurse, and give birth.
A Worrying Decline in Calves and Mating Activity
One of the most distressing signs this year is the historically low number of mother-calf pairs in Laguna San Ignacio, a key breeding ground. According to Dr. Steven Swartz of the Gray Whale Research team, only five mother-calf pairs were spotted—the lowest ever recorded since research began in the late 1970s.
Whale Deaths Increasing Along the Migration Route
As the whales begin their 6,000-mile northward migration to feeding grounds in the Arctic, the body count is rising. In just the last two weeks, three gray whale carcasses were discovered in San Francisco Bay. At least one was found to be malnourished and emaciated, suggesting a possible lack of food.
Scientists Observing Record-Low Migration Numbers
Marine biologist Alisa Schulman-Janiger, who has been leading whale migration monitoring in Los Angeles since 1979, reported record-low sightings this year.
“We didn’t see a single southbound calf—something that’s never happened in over 40 years,” she said.
This lack of calves raises serious questions about the species’ reproductive health and the overall condition of the population.
Possible Causes: Climate Change, Food Shortages, and Human Activity
Although the exact reason behind the gray whale die-off remains unclear, scientists are pointing to a combination of environmental stressors:
- Declining Arctic food sources such as amphipods and small crustaceans
- Climate change affecting oceanic productivity
- Microplastic pollution, toxic algae, and chemical exposure
- Increased risks from ship strikes, discarded fishing gear, and killer whale predation
Many gray whales are now seen feeding in unusual locations like San Francisco Bay and Long Beach—areas never known for whale foraging behavior. This could indicate that traditional feeding grounds in the Bering and Chukchi Seas are no longer sufficient.
Echoes of the 2019 Mortality Event
This situation feels eerily similar to the gray whale die-off in 2019, when over 200 whales were found dead along the North American Pacific Coast. That prompted a formal investigation by NOAA into what was deemed an Unusual Mortality Event (UME). Although the investigation ended in 2023, no definitive cause was ever determined.
What Researchers Are Saying Now
NOAA spokesperson Michael Milstein stated that while recent deaths are concerning, the current stranding numbers are still below average—with only seven in California and one in Washington so far in 2025.
But researchers like Schulman-Janiger caution that we are just entering the peak stranding season (April to June), and more deaths could still occur. Additionally, La Niña ocean conditions and shifts in migratory paths may be affecting whale visibility this year.
“It’s a very strange year for gray whales,” she added. “Given their body condition, the strandings, and the very low calf numbers, we’re deeply concerned.”
Final Thoughts
Whether the cause is climate-driven changes in the Arctic, food stress, or something else entirely, the continued decline in gray whale health and reproduction is a red flag for marine ecosystems. Ongoing monitoring and coordinated international research are essential to protecting these iconic ocean travelers.