Kategorie: News
16,000 Stingrays on a Football Field
On some beaches in Southern California, the sand is barely visible these days—not because of sunbathers, but because of stingrays. A prolonged heat wave in the Pacific is driving record numbers of the animals toward the coast.
The situation is particularly challenging in Seal Beach, southeast of Los Angeles, which has been nicknamed “Ray Bay” for decades. Marine biologist Chris Lowe, director of the Shark Lab at California State University, Long Beach, estimates that on some days, more than 16,000 round stingrays can gather there in an area the size of a football field. The animals, mostly no larger than a dinner plate, have been congregating at this spot for at least 60 years—drawn by warm cooling water discharged into the ocean by a nearby power plant, as well as a fine-sediment seabed that provides ideal living conditions.
This year, however, there is an additional factor: a widespread marine heatwave off the U.S. West Coast. According to meteorologists, this is the third such event since records began. Water temperatures have remained unusually high for weeks—a reason for the heat-loving rays to stay near the coast in even greater numbers. The effect is amplified by an emerging El Niño event, which is driving more subtropical rays northward from the Gulf of California.
Another factor that researchers like Lowe are observing is the trend among the rays’ predators: sharks, sea lions, and large groupers have declined in parts of the region or altered their behavior—with the result that the ray population is less regulated and can spread more freely near the coast.
This is particularly noticeable to beachgoers: At Bolsa Chica and Huntington State Beaches alone, more than 3,100 sting injuries have already been reported this year—more than twice as many as in all of last year. More than 2,000 cases occurred along Huntington Beach’s approximately 5.6-kilometer stretch of coastline, and in San Diego, more than 900 were reported in the first half of the year alone—more than in any of the past five years during the same period. The stings are extremely painful due to a neurotoxin in the tail spine, but are generally not life-threatening.
Advice from Lifeguards
To avoid injuries, lifeguards recommend the so-called “Stingray Shuffle”: When entering the water, shuffle your feet across the sand instead of walking normally. The disturbance usually scares off the stingrays buried in the sand in time, so they swim away instead of stinging. Given the persistently warm waters, the situation is unlikely to improve in the coming weeks—shuffling remains the best defense for now.
Further information:
KPBS
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