The U.S. Coast Guard has ceased using Mobile Bay for certain types of training after rescue swimmers reportedly became sick.

Rescue swimmers, who interact with water in the bay more than other Coast Guard personnel, will now conduct training in the Gulf of Mexico, according to a U.S. Coast Guard statement.

“This precautionary measure was taken after our rescue swimmers noted symptoms of illness and irritation after working in Mobile Bay,” said Capt. William Sasser, the commanding officer of Coast Guard Aviation Training Center Mobile. “While the water samples taken did not exceed acceptable levels, the decision to move the training was precautionary as the health and safety of our crews is a top priority.”

Sasser said moving the training offshore had enabled aircrews to “train in an environment with more sea state and possibly less horizon references, which enhances their ability to be effective in real world situations.”

Coast Guard rescue swimmers are some of the most elite personnel in the U.S. military, often being asked to respond to extreme emergencies including rescues in hurricane-level seas. Attrition rates during the 24-week training course have been as high as 85 percent, according to the Coast Guard. By comparison, Navy Seal attrition rates are about 75 percent.

Sasser also said the health of rescue swimmers had improved since the move, while new cleaning and hygiene policies had also helped.

“While we cannot attribute any one cause or time period to the reports of illness and irritation, we have seen a benefit to overall rescue swimmer health since moving offshore, where the water has a higher degree of salinity and a higher volume of water, and implementing better sanitary measures," he said.

The press release didn’t give a timeline of how long the issue had been going on or what type of illnesses or irritation personnel had experienced.

Sasser said the Coast Guard was not an authority on water quality and that weekly testing had shown levels of the Enterococci bacteria to be within acceptable ranges. Water quality from various in Mobile and Baldwin County can be viewed online.

The Mobile Baykeeper said that everyone in the community has to do their part in keeping the bay clean.

“We hate to see anyone question their ability to swim, fish, or play in Mobile Bay,” said Casi Callaway, the Executive Director of the Mobile Baykeeper. “A healthy Mobile Bay is dependent on all of us doing our part – keeping sewage out of Mobile Bay, reducing legal and illegal pollution dumping into area waterways, and investing in the infrastructure (pipes, drainage, etc.) that will reduce stormwater, sewage, and other pollution from entering our waterways.”

Callaway suggested the issue facing the rescue swimmers may be related to Vibrio vulnificus, a naturally occurring bacteria that can infect people through open wounds or from under cooked shellfish.

“Warmer waters in the Gulf and drought upstream are allowing more of it to enter Mobile Bay,” she said of the bacteria. “There’s no quick test for Vibrio, but we are hoping scientists come up with one soon so that we can know when and where it is safe to swim.”

Vibrio is typically present in salty or brackish water and are present in higher concentrations between May and October, according to the Center for Disease Control and Prevention. The bacteria can be more prevalent during hurricane season.

Over the summer, heavy rains from Tropical Storm Barry overwhelmed local sewer systems where approximately 300,000 gallons of sewage spewed out into creeks and other bodies of water connected to Mobile Bay. The bay is about 413 square miles in area but is fed by a watershed that covers two-thirds of Alabama, some 45,000 square miles.

Such spills are fairly common.

In 2018, just under 3.4 million gallons of untreated sewage spilled into waterways in Mobile and Baldwin County, according to the Mobile Baykeeper’s analysis of information provided by the Alabama Department of Environmental Management. The figure is significantly down from 2017 when 25.8 million gallons of raw sewage spilled into local waters.

The move by the Coast Guard also comes during a period of environmental policy upheaval within the federal government. Dozens of President Barack Obama-era environmental policies have been scrapped, including clean water regulations that were designed to further protect small bodies of water from pollution. Some of the biggest lobbyists against the new regulations were utility companies.

After years of legal wrangling in dozens of states, President Donald Trump scrapped the new rules.