In the foamy chop of the warm-water discharge flowing into the San Gabriel River from a Long Beach power plant, a green sea turtle, wide as a manhole cover, materialized Friday just a few yards from shore.
A few minutes later, an even larger sea turtle surfaced in the murky water near the plant's thicket of steel scaffolding, steam vents and transmission lines.
Green sea turtles usually have tropical haunts -- teeming coral reefs or white sandy beaches where they lay eggs -- but these chunky titans live more than a mile upstream in one of Southern California's most ecologically degraded rivers.
Little is known about the colony of at least six urban sea turtles. But a joint study by the National Marine Fisheries Service and the Aquarium of the Pacific aims to determine, among other things, what they're doing in there.
"Right now, it's a small group of what might be considered oddball turtles," said Peter Dutton, a senior researcher with the fisheries service. "But we have a lot to learn about them. Are they part of a more complex sea-turtle migration dynamic than we ever imagined, or just lost wanderers?"
Scientists also want to know how the federally endangered animals are adapting to the unique challenges they face in the 100-yard-wide river channel at the Los Angeles County-Orange County line, next to the Los Angeles Department of Water and Power's Haynes Generating Station. Those challenges include speedboats, water skiers, baited hooks, urban runoff, tons of garbage and harassment.
On Friday, a green sea turtle that had been trapped for weeks in the whirlpools of an intake channel near the power plant a few yards east of the river was rescued by a team of divers hired by the DWP. The 45-pound turtle was taken to the Aquarium of the Pacific, where veterinarians discovered a hook in its rear left flipper and a hook and a 3-inch gash in its front left flipper.
This week, witnesses told federal wildlife authorities that several fishermen had repeatedly tried to snag the animal. One man, they said, hooked onto one of its rear flippers and struggled for about an hour and half trying to bring the animal to shore. Eventually, the fishing line snapped and the turtle swam free.
Aquarium officials said they planned to release the turtle into the river in the vicinity of the power plant.
