THURSDAY, May 31, 2018 (HealthDay News) -- Can dogs help keep nasty bacteria off the beaches?
A new study suggests it's possible: E. coli spread by seagull droppings prompts beach closings, but dog patrols that chased the birds away did their part in keeping beaches open.
The bacteria can be spread by other birds and other animals, even dogs, but gulls are the primary culprit, the researchers noted.
"It's important to encourage access to these important natural areas," said Meredith Nevers, a research ecologist with the U.S. Geological Survey. "Finding and eliminating the source of E. coli, which is one reason for closing beaches, can lead to fewer beach closings and more people getting to the beach."
For the study, Nevers and her colleagues sampled water from Lake Michigan beaches in Indiana in 2015 and 2016 in an area that includes the Grand Calumet River.
"This was identified as an area of concern in 1987," Nevers said. "The area had a high amount of pollution, as well as a high number of beach closings. The Grand Calumet River is low-gradient, meaning its flow isn't usually very fast. This can cause pollution to stay in place, rather than flowing out of the river to Lake Michigan."
Levels of E. coli are one factor in determining whether to close a beach. E. coli may not be the cause of health risks, but its presence can indicate that more harmful germs are in the water, the researchers explained.
To gauge the level of E. coli, Nevers and her team looked to animal poop. In all of the beaches sampled, gulls were the major source of E. coli that led to beach closings, the researchers found.
Next, the researchers looked for ways to control the spread of E. coli. They turned to dog patrols. Dogs patrolled the beaches from sunrise to 7 p.m. for one month in 2015 and from June through September in 2016.
The dog patrols reduced the presence of gulls by nearly 100 percent. They also cut the number of times per day that gulls were present on or near the beaches by 93 percent. This resulted in fewer beach closings, the researchers reported.
The report was published May 23 in the Journal of Environmental Quality.
The dogs were specially trained for their job of gull deterrence, and their handlers made sure the dogs "left no trace behind," the researchers added in a journal news release.
Visit the U.S. Centers for Disease Control and Prevention for more on E. coli.