To Swim or Not to Swim

Closer monitoring by scientists helps outdoor enthusiasts decide when it’s safe to jump in

by Rona Kobell

A sign posted at Lake Needwood in Rockville, Md. this summer warns visitors to avoid contact with the water because of a dangerous toxic bloom of blue-green algae. Photo, Dan Gross / The Frederick News-Post
A sign posted at Lake Needwood in Rockville, Md. this summer warns visitors to avoid contact with the water because of a dangerous toxic bloom of blue-green algae. Photo, Dan Gross / The Frederick News-Post

The Arundel Breakfast Club is convening its Saturday meeting. And yes, someone remembered to bring the doughnuts. But they are almost beside the point.

This club is about swimming—in the rivers, for miles at a time, hugging a shoreline chock-a-block with piers and powerboats and making way for the occasional otter or dolphin. About two dozen people in this tight-knit swim league have been circumnavigating a four-mile loop on weekend mornings. This morning they launch at a community beach in Arnold under a sherbet sunrise. Some train for the Great Chesapeake Bay Swim, while others have crossed the English Channel, Lake Champlain, or circled the island of Manhattan. They are defense contractors, entrepreneurs, police officers, and government workers from Annapolis to Bowie, Baltimore to Washington. Neither brain tumors nor back surgeries—both of which some breakfast clubbers have experienced—have stopped them from a routine that is part meditation and part exercise, and one that has also made them stewards of the rivers they depend on.

Two years ago, stalwart breakfast clubber Mark Milleker contracted a staph infection that left him hospitalized for five days. Milleker, a 56-year-old technology executive, was cleaning his boat when he scraped his shin, breaking the skin. He cleaned the wound, forgot about it, and swam as usual in the Magothy River near his house a few days later. Shortly afterward, he woke up in the middle of the night in excruciating pain, suffering from a headache, nausea, and a high fever. After a couple of misdiagnoses, he said, doctors concluded that Staphylococcus bacteria from the river had entered the cut. They treated him with intravenous antibiotics until he was healthy enough to go home. Unlike some victims of serious bacterial infections, Milleker left the hospital with all his limbs and without having to undergo serious surgery. He was lucky.

Better, and worse

In an average year, about 15 of every 1,000 people who swim or wade recreationally in the United States will become ill from water contact, according to a study published in the journal Environmental Health that was led by Environmental Protection Agency (EPA) epidemiologist Stephanie DeFlorio-Barker. The researchers also estimated that more than 90 million cases of recreational waterborne illness occur each year, with varying degrees of severity, from skin rashes to serious infections requiring hospitalization.

Bacterial infections like Milleker’s are still rare in Maryland, but many summers a bad case or two surfaces. Last year, Frederick County fisherman Al Geisler nearly lost his leg after a spike from a rockfish poked him and Vibrio bacteria entered the punctured skin. In 2010, Calvert County crabber Mauro Lanzisera tripped on his dock as he was trying to get to his boat and jumped into the Patuxent River to catch the rope. He had an open wound from his fall when he entered the water. Lanzisera ended up spending a month in the hospital, with an eventual diagnosis of a Vibrio vulnificus infection. This summer, a boy contracted a skin infection that was diagnosed as Vibrio, according to his mother, after swimming in a bay near Ocean City. It is enough to frighten vacationers and flummox public health officials, who want swimmers and boaters to be safe but don’t want to lose the economic benefits that come from outdoor recreation.

Milleker contracted his infection at a time when, by many measures, the water quality in the Chesapeake Bay and many of its rivers is improving. Upgrades to sewage treatment plants, new regulations on fertilizer applied to fields by farmers, and better storm water management practices have pushed the effort along. Also helping are new requirements for denitrifying septic systems in waterfront areas.

But climate change may be turning the tide yet again as it brings warmer water temperatures that bacteria crave, according to recent findings reported by the National Academy of Sciences. Waterborne bacteria, such as Vibrio, Staphylococcus, Enterococcus, and Streptococcus, can enter the body through open wounds and cause serious infections and even death. Public health officials and scientists have noticed an uptick in bacterial infections over the past 15 years. Meanwhile, officials at the National Oceanic and Atmospheric Administration’s Oxford Cooperative Laboratory on the Eastern Shore are using temperature data to map areas in the Chesapeake Bay where the bacteria are likely to thrive, and they are seeing areas of concern becoming more extensive.

In 2016, Rita Colwell, a University of Maryland and Johns Hopkins University researcher, was one of nine scientists from around the world who published a study that linked rising ocean temperatures in Europe to increasing numbers of Vibrio species in the water that are potentially harmful for humans. The study, which Colwell believes is the first to explore the connection, examined plankton samples collected over the last half-century and retroactively assessed their Vibrio concentrations, then compared those numbers to recent samples in nine areas. In every case but one (Newfoundland), the number of Vibrio bacteria had increased, which correlated with an increase in water temperatures of up to 1.5 degrees Celsius over the past several decades.

The number of infections caused by Vibrio is also increasing, the researchers found. It’s not what Colwell, the former director of the National Science Foundation and Maryland Sea Grant, would call an epidemic. But it is, she said, a concern.

Shorter and more intense rain events due to climate change wash nutrients into local waterways in higher concentrations that help these colonies thrive. Colwell said that both warmer temperatures and more nutrients contribute to favorable conditions for the bacteria.

“It is a bacterium that grows rapidly under optimal conditions in the laboratory,” Colwell said, pointing out that longer, hotter summers and shorter winters and optimal salinity could create such conditions in the Chesapeake estuary as its water warms.

The increased number of infections in the Chesapeake Bay region caused by one species, Vibrio vulnificus, presents scientists and those working on restoration efforts with a conundrum: how to responsibly encourage people to use local waterways without putting them at risk. It is a delicate balance that swim groups like the Arundel Breakfast Club understand, because environmental stewardship helps ensure clean water for their recreational needs.

A Culture of Swimming

Tammy Domanski, a microbiologist at Anne Arundel Community College, uses a secchi disk to test water clarity near the Eastport Yacht Club in Annapolis. Photo, Nicky Lehming / MDSG
Tammy Domanski, a microbiologist at Anne Arundel Community College, uses a secchi disk to test water clarity near the Eastport Yacht Club in Annapolis. Photo, Nicky Lehming / MDSG

When Tammy Domanski asked a group of teenagers to describe the quality of the water on a recent visit to Spa Creek in Annapolis, she heard the usual answers: “Horrible.” “Dirty.” “Full of sediment.” But Domanski, a microbiologist at Anne Arundel Community College, knows the data tell a different story. She’s part of a nearly three-decade effort to collect bacteria counts, post them on a public website, and communicate with county health officials when necessary.

Domanski is the scientific director of Operation Clearwater, a nonprofit connected with the college that runs weekly tests on more than 70 community beaches in Anne Arundel County to determine bacteria levels and also temperature, pH, dissolved oxygen, and salinity. Community associations pay her to do it because residents use the rivers. Many other water quality monitoring organizations and environmental groups throughout the state rely on citizen scientists and research partners to do their own testing. Domanski gets results within 24 hours and uploads them to the Operation Clearwater website as soon as possible.

While many counties have mostly private piers and beaches, Anne Arundel has dozens of communities on the Severn, South, and Magothy rivers that share beaches, kayak launches, and piers. The arrangement—which is called “water privileged” instead of “waterfront” because communities share communal property with water access—hearkens back to the days when the now year-round communities were summer cottages for Baltimoreans. Homes are more affordable because they share the waterfront, and maintenance costs are also shared across community associations. One community, Sherwood Forest, even has a summer camp where children swim in the Severn almost every day.

James Fegley, a longtime, competitive open-river swimmer and professional photographer who lives on the Severn, said he pays attention to Domanski’s reports. “I am not driven with a lot of worry,” he said. “But if nothing else, it makes you kind of aware.”

The communities rely on Domanski to make what are, if not life-and-death decisions, then potentially life-and-limb ones. The Arundel Breakfast Club leader reviews Operation Clearwater data every week and sends an email to the group to determine whether the counts indicate it’s safe to swim. In recent years, the answer is almost always yes.

Simple question, complicated answer

Biology major Stephanie Vargas looks at a water sample. Photo, Nicky Lehming / MDSG
Biology major Stephanie Vargas looks at a water sample. Photo, Nicky Lehming / MDSG

Domanski said the answer to the “safe to swim” question is always a little complicated. “I’m very leery about giving labels,” she said. “This is data. Some parameters are improving, some are not improving. It’s really important to dig into what that means.”

She generally advises swimmers to stay out of the water for 48 hours after rainfall of half an inch or more, a not-uncommon occurrence in recent years. Her website also advises swimmers and boaters who have a cut or any type of break in the skin not to go in the water.

In the Operation Clearwater lab, biology major Stephanie Vargas analyzes the samples. A safe measurement for swimming is 104 enterococci per 100 milliliters of water, according to the EPA. Enterococci are indicators that show whether fecal matter is present in the water. Often, there is a localized reason for high counts in one spot. Vargas, Domanski, and the team work with Erik Michelsen of the Anne Arundel County Watershed Protection and Restoration program to determine the cause. Sometimes it’s a dog beach with lots of pet waste. Sometimes it’s a flock of geese.

Residents know what the state of the rivers is at all times, Michelsen said. The rare incidence of alarmingly high counts, such as those last year due to unusual amounts of rain, will make the news and frighten residents.

“It’s kind of an ironic situation in that there’s a perception that local waters are more dangerous than they have been in the past, when the reality is they are quite a bit less dangerous,”

said Michelsen, whose children swim in a Severn that is much cleaner now than when he was a kid in the 1980s. “We’ve been very effective in establishing that there are problems with the Bay. The difficulty then becomes convincing people, as things improve, that things have improved.”

Colwell’s warning, that the Bay may provide more optimal conditions for Vibrio as the water warms, may come to pass. But for now, community beaches up and down its tributaries, like the Severn and Magothy, are busy with splashing children, romping dogs, and serious swimmers.

As for Milleker, he was back in the water with the Arundel Breakfast Club as soon as his wound healed. Asked if the infection gave him pause, he shrugged and said, “Not for a minute.”

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