It's slime time on Southern California beaches. But that's a good thing.
Black sea hares — the largest of the sea slug species — appear to be showing up on Orange County beaches in greater numbers, the Orange County Register reported.
The slimy, shiny black mollusks have been spotted from as far north as Redondo Beach to San Clemente and Corona del Mar. They feed offshore but have shown up in tide pools and wedged between rocks.
Ali Huerta, 22, of Mission Viejo, accidentally stepped on some after surfing at San Onofre State Beach on Thursday.
"They are really, seriously slimy," she said. "I like when there's animals in the water, it's kind of cool. I also don't want to squish them, I feel bad."
"They're everywhere," said Savannah Parsen, who took her 4-year-old daughter to San Clemente. "You can see them floating all over the place."
Aplysia vaccaria, as the species is known scientifically, lives on algae and kelp. It is found off of California and Mexico's Baja California coast.
The black sea hare is "one of the most spectacular marine creatures we have along our coast," said Julianne Steers, a biologist with the Ocean Institute in Dana Point.
The species hasn't been seen in big numbers for at least a decade but recent algae blooms have helped feed the population, she told the Register.
The ones spotted on local beaches are about the size of a hand but the slugs can grow disturbingly large; they've been known to reach 3 feet long and weigh 30 pounds.
"Most often, they are somewhere in the 6- to 10-pound range," Steers said. "They get that big by consuming a buffet of algae. It's definitely not your garden variety snail."
The increased population is a good thing, Steers said.
"It's definitely a sign of a healthier ocean," she said. "We still have a way to go, but it's definitely a rebound."