Murky mystery: Cloudy water off La Jolla Shores raises questions but is thought to be ‘natural’

A large mass of cloudy ocean water that appeared recently off La Jolla has raised questions from locals, but experts say there’s no cause for concern.

The oddly shaped patch, photographed by resident Scott Fairchild on June 14, appeared off La Jolla Shores between The Marine Room restaurant and the caves at La Jolla Cove.

It seemed to be “some kind of a discharge,” said Shores resident Joe Dicks, one of several La Jollans who raised concerns about the area, a designated ecological preserve.

Fairchild, who often snorkels there, said that although that particular stretch of water “always has the worst visibility, [June 14] seemed oddly unique. The ‘line’ separating the good and bad ... was so distinct, almost like oil and vinegar.”

Dicks said the murky water also was present July 11.

Matt O’Malley, executive director and managing attorney for environmental group San Diego Coastkeeper, said, “Our team was out snorkeling that area [the week of July 5] after we saw the picture and noticed it was murky, but there was no discernible discharge causing it.”

“Based on what we saw, it’s our best guess that it’s a natural phenomenon,” he said. “Waves often crash against the seawalls and caves in that area, causing some interesting conditions.”

Ed Parnell, a marine ecologist at the Scripps Institution of Oceanography in La Jolla who studies human effects on the coastal zone and the ecology of kelp forests and the coastal shelf environment, said the murky water “is as natural as you could expect.”

“That corner of the reserve is flanked by cliffs that are really fine-grained,” Parnell said. Sediment from the cliffs is “very prone to being suspended by surface wave action from swells coming in at the right angle or by strong afternoon winds, which lead to these turbid plumes.”

The cloudiness of the water in the area “is especially bad after a really high tide that laps up at any recently fallen sediments at the upper edge of the beach,” Parnell said. The condition is further exacerbated “given that the clifftops are highly developed and irrigated, which speeds up erosion.”

Donna Durckel, communications officer for the San Diego County Land Use and Environment Group, said the county’s Department of Environmental Health and Quality inspected the site June 15 and “found there was no smell or debris.”

She said the department “also checked with the city of San Diego and there were no reports of discharge. DEHQ’s routine water sampling conducted the morning of June 15 was also within state health standards.” ◆