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Stanford Study Aims to Clear the Water at Santa Cruz's Cowell Beach


Written by Maria Gaura

La Vida Local

SANTA CRUZ (June 2011) – Cowell Beach is one of the most popular family beaches in Santa Cruz County, but persistently high levels of bacteria in the water have been putting a damper on summer fun in recent years.

The waterline at Cowell has been posted with warning signs most days for the past two summers, and the signs are likely to be a fixture this summer as well. Adding insult to injury, Cowell was recently named the biggest “Beach Bummer” in California by the environmental group Heal the Bay.

Cleaning up the contamination at Cowell has been stymied by coastal regulations, as well as disagreement over the source of the noxious bacteria. But a scientific study by researchers from Stanford University and the Southern California Coastal Water Research Project (SCCWRP) aims to help clear up the confusion and, eventually, the water at Cowell Beach.  


City officials are asking the California Coastal Commission to approve a two-year study on Cowell Beach aimed at determining whether piles of kelp left to rot on the beach are the main source of the water pollution, or whether the area’s sea lions, pelicans and fish are the real culprits. Ongoing testing by the county’s Environmental Health Department has already ruled out human sewage as the bacterial source.

The proposed update of Santa Cruz's Beach Management Plan, to be presented to the Coastal Commission at its June 16th meeting, would continue the current level of beach maintenance for the rest of this year, allowing researchers to take samples and establish a baseline of water quality data. Next year, if the plan is approved, the beach will be regularly cleared of kelp piles, allowing researchers to measure any effect on bacteria levels.

“The Coastal Commission had asked us to come up with a method to evaluate the effect that kelp removal would have on the species that are supported by kelp on the city's beaches,” said Dannettee Shoemaker, Director of the city’s Parks and Recreation Department. “This is a great opportunity to do that, and to put an end to the uncertainty, all without additional cost to the city.”

While the Cowell Beach study is a big deal for Santa Cruz, it is a small portion of the researchers’ overall project, according to Steve Weisberg, Executive Director of SCCWRP. “The Cowell Beach study is a small part of a much larger collaboration between researchers at Stanford, UCLA, UC Santa Barbara and (SCCWRP) to develop protocols for bacterial source identification,” Weisberg said.

Researchers are working to identify the best methods for linking individual bacteria samples to the type of animal that excreted it. One important part of the study involved sending unidentified samples of feces to researchers and challenging them to accurately identify the source animal.

“We created blind samples,” Weisberg said. “We know where the poop came from because we grabbed it from the back end of the cow, horse, bird, or other animal, and shipped it to the researchers.”

A good, accurate method of bacterial identification will be crucial to determining the source of pollution at places like Cowell Beach, where bacteria can originate from a variety of sources. But the local portion of the study will also look at whether bacteria that originated in an animal’s gut can reproduce and thrive in piles of warm, decomposing vegetable matter, resulting in significant water pollution.

In the meantime, beach visitors and hundreds of local kids enrolled in the city’s summer beach programs will have to play in the cleaner water at the west end of Cowell Beach, or relocate to nearby Main Beach, to avoid exposure to possibly harmful bacteria.

In addition to editing, Maria Gaura currently serves as a Parks and Recreation Commissioner for the City of Santa Cruz.