Some of the dead western gulls that washed ashore in Huntington Beach last month tested positive for a type of botulism more commonly associated with humans.
That was the finding from necropsies performed on the birds, the Wetlands & Wildlife Care Center said Friday.
Personnel from the care center responded Oct. 10 to a report of dead or dying sea gulls at Huntington State Beach, across from the nonprofit organization’s facility. The workers found a dozen beached western gulls.
With the help of a lifeguard, they rescued four gulls that were found tangled in seaweed at the high tide line, according to the care center.
Eight other beached seabirds found at the site were already dead.
The live sea gulls suffered from general paresis so severe that they couldn’t close their eyes. One ended up dying, according to the center.
Two of the remaining gulls were released this week; the third remains in the organization’s care.
Necropsies performed at UC Davis on two birds found they had enlarged hearts and livers, a sign of acute toxicity.
Five other gulls were sent to the California Department of Fish and Wildlife’s investigative laboratory, which found the toxicity was from botulism Type A, according to the care center. The results were released Friday.
The source of the illnesses is unknown, but five more exhibiting the same symptoms were recovered in the area in the past few weeks, officials said. Two have died, and three are being treated at the Wetlands & Wildlife Care Center.
Type A is more common in humans, with improperly canned foods among the most common sources.
In humans, the serious and potentially deadly illness can cause difficulty breathing and muscle paralysis, according to the U.S. Centers for Disease Control and Prevention.
The most common form of botulism found in birds is Type C. Type E is occasionally diagnosed among those that eat fish.
Anyone who sees a sick or weak seabird in Orange County is asked to contact the Wetlands & Wildlife Care Center at (714) 374-5587.