Massive Bird Die-Off at Salton Sea Raises Environmental Concerns

Thousands of birds were discovered dead at the Salton Sea last month, raising new concerns about the lake's declining health.

California Department of Fish and Wildlife workers cleaned up the carcasses at the Sonny Bono Salton Sea National Wildlife Refuge after hunters initially reported the gruesome bird die-off. More than 400 species of birds use the Salton Sea’s wetlands as a stop along the Pacific flyway for migratory birds.

The man-made Salton Sea is receiving less and less water from agricultural runoff and the Colorado River, causing it to shrink dramatically. Andrea Jones, director of bird conservation for Audubon California, said the birds fell victim to avian cholera, a contagious disease, due to overcrowding.

“Thousands of birds died in a couple-week stretch from a disease that is not entirely uncommon for birds, particularly ducks or geese when they crowd into situations instead of having a lot of habitat,” Jones said.

The shrinking sea leaves less habitat for migratory birds, which leads to them being concentrated in small areas, according to Tim Krantz, a professor of environmental studies at the University of Redlands and a renowned expert on the Salton Sea.

“If there are some diseased individuals and then they get concentrated just beak-to-beak, wing-to-wing, they're so crowded on the fields and then the water, at the south end particularly, then that is the place where the contagion is going to manifest itself,” Krantz said.

But that’s not the only way birds are being affected by the lake’s decline. The lake has become saltier as it’s shrunk, killing off nearly every species of fish that migratory birds rely on for food.

“There's still some tilapia out there, even those are not reproductive anymore,” Krantz said. “So a couple more years, there will be no fish in the sea.”

And the lake’s shrinking isn’t just bad for birds — it’s also bad for humans. As the lake shrinks and more lakebed is exposed, the salts that were in the water go into the air. They’re then breathed in by humans.

“These are super-fine silts, two millionths of a meter, two microns in size, I can get a hundred in the width of a human hair,” Krantz said. “If you breathe these sediments into these lungs you can't cough them out, they're too small — they'll profuse directly through your lung tissue into your bloodstream, carrying with them the minerals that are attached to them ... arsenic, selenium, cadmium, bad stuff.”

It could lead to a public health disaster as more of the lakebed is exposed. The bird die-off is a sign that the state needs to address the issue of the Salton Sea immediately, according to Jones.

“We knew something like this could happen, and it's a call to action to the state to get the habitats built, that they are in the process of designing at the Salton Sea,” Jones said. “We need to get the word out that both for the health of the birds and for the health of the people in the region, we need to do something about the Salton Sea as quickly as possible.”