Seabird Deaths Linked to Marine Heat Wave off California Coast

The shores of San Diego have become graveyards for seabirds. Marine ornithologist Tammy Russell discovered numerous feathered carcasses scattered across the beach. Some were intertwined with kelp, while others lay beneath rocks.

Each month, scientists and volunteers survey dead seabirds, revealing the troubling effects of a prolonged marine heat wave off the California coast. These surveys, conducted by various organizations for decades, provide vital data on beached sea life to detect emerging threats.

Tammy Russell, a postdoctoral scholar at UC San Diego’s Scripps Institution of Oceanography, observed numerous seabirds, including brown pelicans, loons, and grebes, dying from starvation. She explained that record ocean temperatures reduced the cold, nutrient-rich waters where small fish thrive.

“We’ve witnessed cormorants walking to the shore and dying within minutes,” Russell said, highlighting the widespread issue along the coast.

Scientists express concern over the potential worsening of the situation due to the recent formation of El Nino. This warming event in the central Pacific can significantly impact global weather patterns and ocean temperatures.

The U.S. National Oceanic and Atmospheric Administration confirmed the El Nino’s formation, predicting it will reach historic intensity. While seabird die-offs occur periodically, the frequency is increasing with the warming planet.

Beach surveys reveal ongoing seabird deaths. Marine heat waves lingered off the West Coast for a year, marking only the third recorded instance of such prolonged warming, according to NOAA.

Daily ocean temperature measurements by Scripps show multiple stations breaking records for extended periods. Robotic gliders also recorded high temperatures off Southern California’s coast.

Russell remarked, “We don’t know how bad this is going to get.” The combination of marine heat waves and El Nino disrupts food webs, altering the habitat for various species from whales to seabirds.

Unusual food-seeking behavior in seabirds becomes evident as they starve. Wildlife conservation groups treated hundreds of malnourished birds this spring. J.D. Bergeron, CEO of International Bird Rescue, notes pelicans searching inland and near human activity for sustenance.

The California Department of Fish and Wildlife reported that most examined seabirds tested negative for bird flu, but many were young and emaciated. Opportunistic infections linked to malnutrition were also noted.

High mortality rates among young Brandt’s cormorants and common murres occurred after a robust breeding season and coincided with marine heat waves.

Only a fraction of birds dying at sea wash ashore, providing limited data. Past events like the 2013 “blob” off Alaska, followed by El Nino in 2015, resulted in massive seabird die-offs.

Common murres, resembling thin penguins, require substantial food intake due to high metabolism. Shortages can lead to fatal starvation within days.

Studies reveal a small percentage of sea deaths reach shores. The impact of marine heat waves on seabird populations remains significant.

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