Environmental group collects tar balls in effort to identify source

Ariadne Reynolds and Brian Stirling peered through binoculars, scanning Manhattan Beach for signs of oil or tar balls from aboard a 21-foot, open-deck motorboat. Other than sometimes catching a whiff of oil, they had yet to find anything. Until —

“Black! In the water!” shouted Stirling, an intern with the Bay Foundation, pointing to a dark lump bobbing in the ocean.

Reynolds, a staffer, pulled on latex gloves and opened a small glass jar to collect the sample. She leaned over the edge of the boat and scooped up the hamburger slider-sized tar patty, then brought it to eye level and shook it gently. It was a few inches long and a quarter of an inch thick, shedding little black specks that floated inside the jar.

Dozens of tar balls washed ashore in the South Bay on Wednesday, causing beaches to close along nearly nine miles of coastline from El Segundo to Redondo Beach. Scientists with the U.S. Coast Guard and the National Oceanic and Atmospheric Administration are investigating the cause, including whether the gunk is related to last week’s oil spill in Santa Barbara County.

The beaches are closed indefinitely while scientists study the substances and cleanup crews remove the last 10% of tar balls, which were baseball- to football-sized, officials said. Test results to determine the source and composition of the petroleum product could take a few days to several weeks.

In the meantime, staff of the environmental nonprofit foundation, which works to protect Santa Monica Bay, took a trip Thursday to see the tar balls for themselves. They hoped to find nothing.

At the helm, Heather Burdick pressed a button on the boat’s GPS to capture the coordinates of where the tar was found. They would pass the data along to government agencies.

“No one’s identified the source of the spill, so it’s good to keep an eye on it either way so we can say, ‘OK, we saw these pieces of tar in these places,’ and we can track them over time and see if it’s spreading or if it’s just a one-time event,” Reynolds said.

Another sample was more difficult to collect. Even slight movement of the boat disturbed the water. But Reynolds finally scooped up the second glob of tar. They found a third ball bobbing at Hermosa Beach. From there, they headed toward kelp forests along the edge of the Palos Verdes Peninsula.

The crew worried that restoration work on the underwater forests might have been hurt by the spill. The kelp’s long, leafy fingers slow the movement of water and could act as a net for tar-like substances.

Kelp forests in the Palos Verdes Peninsula have seen a major decline in the past century, partly because of a boom in purple sea urchins that have covered the sea floor, pushing out other life. Hundreds of species of fish, invertebrates and other algae depend on kelp for food.

Staffers with the Bay Foundation, like Reynolds and Burdick, and other partner organizations dive into the ocean and smash the urchins with hammers, giving the kelp time and space to grow. In the past year and a half, the group has restored about 28 acres of the sea floor and removed 2.5 million sea urchins from Lunada Bay to Golden Cove.

Over the boat motor’s loud humming, Burdick told the group she was looking for less dense patches of kelp to traverse. Seaweed gathered near the prop, and Burdick often had to put the motor in reverse to eject leaves.

Looking over the water with binoculars, the group spotted no traces of oil or tar in the kelp forests, though a white metallic balloon was seen in the leafy canopy.

“We pick up every balloon we see out here. They’re a little easier to catch than tar balls,” Burdick said with a grin.

After about four hours on the bay, it was time to head back.

“We’re really happy that we didn’t find oil sheens and wildlife covered in oil,” Burdick said, “but I think everybody just needs to keep an eye out for that stuff.”

Cruising toward shore, the boat sailed past massive ships laden with storage containers. Staff members said any one of the many cargo vessels could have released the oily, clotted substances. But they also could have been a natural seepage.

For now, it remains a mystery.

taylor.goldenstein@latimes.com

Times staffer Veronica Rocha contributed to this report.