Megan Stone
Special to Mustang Daily
Cal Poly students and faculty are keeping watch on the waters of the Central Coast to help control and reduce the presence of E. coli. While they collect and analyze all different strains of E. coli, it’s the half dozen strains that cause intestinal upset, illness and even death to watch out for.
Some 13 years ago, an oyster farm in Morro Bay had to shut down harvesting when tests revealed levels of E. coli above acceptable limits. Biological sciences chair Christopher Kitts studied Morro Bay to identify the various sources of E. coli and assisted the oyster farm in finding new ways to reduce levels. It turned out that birds were the No. 1 source of E. coli presence in the water, Kitts said.
“When I worked on it back in 2000, the issue was the oyster farms and the California Department of Health would shut down harvesting at the oyster farm every time the levels get up too high,” Kitts said. “I know that after our study, they changed the way that they set out the oyster bags so birds weren’t roosting on them; big difference.”
The San Luis Obispo County public health department conducts weekly tests from Grover Beach up to San Simeon Bay, Kitts said. It also does some testing at the Morro Bay oyster farm and the National Estuary Program has a volunteer-run water sample-testing regime.
In Morro Bay, it wasn’t a “bad” E. coli that caused the problem at the oyster farm, which was sold. Higher levels of E. coli indicated that there could be an increase of fecal contaminants in the water, Kitts says. Having more fecal matter in the water increases the chances of the presence of other pathogens that can also cause illness.
There is no reason to worry about consuming contaminated seafood, Kitts says.
“I don’t consider Morro Bay to be a horribly contaminated area that I should avoid,” Kitts said. “I eat seafood a couple times a week.”
The public health agency and others like it take water samples and test them on a weekly basis, but they just count the number of E. coli, Kitts said.
“They can’t tell you where those came from,” Kitts said. “What I’ve been doing is trying to come up with simple ways to figure out where the bacteria are coming from so that you can go back and say, ‘Well it looks like in Chorro Creek, 50 percent of all E. coli in Chorro Creek are coming from cattle. Maybe we should do something about this.’”
While birds were a primary source of E. coli closer to the ocean, the creeks that drain into local beaches can get E. coli from domesticated animals, some human sources and a lot of farm animals, Kitts said.
“A bunch of property owners that have ranches that border creeks or go into Chorro Creek did some programs of fencing the cattle out of the creeks to see if that would help,” Kitts said.
While the fencing reduced E. coli levels, the levels have been rising. So Kitts and his team of faculty are in the process of following up to determine if the E. coli is still coming from cattle.
While E. coli can make people very sick, it is a good indication of fecal contamination, Kitts said. It means there is likely to be other bacteria, viruses or parasites that are commonly associated with fecal contamination to watch out for, Kitts said.
“E. coli itself is really not all that bad, although you hear about different kinds like O157:H7, there actually are a whole bunch of different strains of E. coli,” Kitts said. “But there are only six that cause problems.”
Taking caution to not swallow water when swimming in lakes or in the ocean will help reduce the risk of coming in contact with E. coli, Kitts said. It will also help prevent the spread of other bacteria and pathogens.
It’s not necessarily drinking water that is a concern; it’s more recreational waters, biological sciences professor Michael Black said.
It’s important to be aware of where sewage gets dumped because reducing the levels of E. coli will make recreational waters safer and cleaner, Black said.
Chemistry and biochemistry professor Anya Goodman works alongside Kitts, Black, other faculty and students to further develop their current analysis and testing methods to make it a process that students can use.
“If there is environmental contamination of some sort, you try to figure out, ‘Where did it come from?’” Goodman says.
Human feces are a concern because humans can contract bacteria and other pathogens, such as Hepatitis A, from human fecal contamination in a water source, Black said.
“I see it getting worse, and I don’t think I’m a pessimist, but as the human population continues to grow and as our demand for food and water continues to grow, then I see we’re going to have more and more problems with that,” Black said.
Megan Stone contributed to this article.