UPDATE, 5:13 p.m. Aug. 30: The advisory at Cannon Beach has been lifted.

There's doo-doo in the water.

The Oregon Health Authority is warning beach goers to stay out of the ocean at some of the state's most popular beaches after elevated levels of bacteria were detected, likely due to fecal matter in the water, officials said Wednesday.

Cannon, Nye and Agate beaches were all under advisories Wednesday morning. Officials don't know whether the advisory will be lifted before Labor Day weekend.

"Water samples indicate higher-than-normal levels of fecal bacteria, which can cause diarrhea, stomach cramps, skin rashes, upper respiratory infections and other illnesses," the agency said in a statement. "People should avoid direct contact with the water in this area until the advisory is lifted."

Children and the elderly are particularly vulnerable to waterborne bacteria, officials said, and all beach goers should avoid nearby creeks, tidepools and any water that appears to be discolored.

It was unclear exactly what was causing the spike in bacteria, though the agency said it can come from sources both on land and offshore. Among those, "stormwater runoff, sewer overflows, failing septic systems, and animal waste from livestock, pets and wildlife" are the likely culprits, officials said.

The agency didn't indicate when the advisories might be lifted, but said conditions can change rapidly and recommended those looking to visit any of the affected beaches check the state's water quality monitoring website.

In the meantime, the beaches themselves will still be open for kite flying, picnicking or frolicking in the sand.

-- Kale Williams

kwilliams@oregonian.com

503-294-4048