Seabird Die-Off in San Diego Linked to Record Ocean Heat Wave

• 📌 A marine heat wave has caused widespread seabird deaths along the California coast, particularly in San Diego County, with species like brown pelicans and cormorants starving due to record-high ocean temperatures.
• 📌 Scientists fear the ongoing El Niño could worsen the die-off, as warming waters disrupt the cold, nutrient-rich band where krill and fish thrive, forcing birds to search inland for food.
• 📌 Wildlife rehabilitation centers have treated hundreds of emaciated birds since March, and postmortem exams show emaciation as the primary cause, with high DDT levels also found in pelicans and cormorants.

Introduction

San Diego’s beaches have become a grim scene for marine biologists, who are documenting a massive seabird die-off linked to a persistent marine heat wave. Since early 2026, record-warm ocean temperatures off California have starved birds like California brown pelicans, Brandt’s cormorants, and common murres, with experts warning that the developing El Niño could amplify the crisis.

Marine Heat Wave and Starvation Crisis

According to the Scripps Institution of Oceanography, ocean temperatures at three coastal stations broke records for 40 or more days this year. “We’ve been seeing cormorants walk to shore and then just die within the hour,” said marine ornithologist Tammy Russell. The heat wave, which has persisted for over a year, is only the third such event on record to cover such a large coastal area for so long without an El Niño.

The warm water reduces the cold, nutrient-rich surface layer where krill, anchovies, and sardines gather, forcing seabirds to search deeper or inland for food. “Brown pelicans are turning up in inland lakes,” noted J.D. Bergeron of International Bird Rescue, which has treated hundreds of emaciated birds since March.

El Niño Threatens to Worsen Conditions

The National Oceanic and Atmospheric Administration confirmed an El Niño formed in June 2026, expected to grow to historic strength. This could further warm the Pacific and disrupt food webs for gray whales and seabirds alike. “We don’t know how bad this is going to get,” Russell said, recalling a similar pattern during the 2015-2016 El Niño that killed 4 million common murres.

Local California Context: San Diego County at the Epicenter

Surveys along San Diego beaches, including Blacks Beach and near Scripps Pier, reveal alarming numbers of dead birds. The Wetlands and Wildlife Care Center in Huntington Beach has taken in over 100 brown pelicans and 66 Brandt’s cormorants since March. Krysta Rogers of the California Department of Fish and Wildlife noted that high juvenile mortality followed a robust 2025 breeding season, but the heat wave is a key factor. Additional stressors include high DDT contamination and fungal infections like aspergillosis.

Conclusion

The seabird die-off along California’s coast is a stark reminder of climate change’s impact on marine ecosystems. As El Niño looms, scientists and wildlife rescuers urge public reporting of sick birds and caution against disturbing them. Continued monitoring and conservation efforts are critical to mitigate future losses.

Sources and Materials

• timesofsandiego
• seattletimes
• newsday
• wsls
• clickorlando