Is It Safe to Swim in the
Wonder if it is safe to swim in the Chesapeake Bay in 2018?
What are the risks of getting sick from swimming in the Bay around Annapolis?
It’s mid-summer and water temperatures are heating up — which means higher bacterial counts. It the perfect time to review what you can get, from where and how to avoid getting any of it.
How to Avoid Getting Sick in the Bay
Of all the rules to live by, the most important is “Do not swim within 48 hours of a rainfall.”
“Anytime after a significant rainfall… we know the water will be overloaded with bacteria,” according to a former director of environmental health for the Anne Arundel County Health Department.
To Avoid Getting Sick in the Chesapeake Bay: 7 Simple Rules
- After rainfall of 1/2 inch or more, all Anne Arundel County beaches are under a no swimming/no direct water contact advisory for at least 48 hours.
- Do not swim in the Bay before checking this site: Anne Arundel County’s Beach Swimming Guide.
- Never swim in cloudy, murky water or if the water has an odd appearance–greener or browner than usual.
- Look for trash and other signs of pollution, such as oil slicks or scum on the water.
- Do not swim in the Bay if you have an ear infection, a perforated eardrum, open cuts, scratches or skin lesions, or a compromised immune system.
- Do not swim in water areas where there is a fish kill or where there are any dead animals or known algae bloom.
- Try not to swallow water while swimming.
When water contact cannot be avoided:
- Cover wounds with water proof bandages
- Carry hand sanitizer to swimming areas and when fishing or crabbing so that wounds that occur can be cleansed immediately or have ready access to soap and water
- Wear water shoes to avoid cuts and scrapes
- Always shower following swimming in natural waters and wash hands before handling food or eating.
If you follow these simple rules, you lower your risk for getting a water-related disease dramatically.
“Which Areas of the Chesapeake are Safest?”
Unfortunately, there is not a single area that is “always safe”. The possibility of sewage leak, or irresponsible boater pumping out, means that any river can suddenly develop high bacterial counts.
Local health departments test for bacteria from human feces (usually E. coli or Enterococci) once or twice per week.
In Annapolis and surrounding areas, these results can be easily found on Anne Arundel Health Department’s website: Water Quality Report . These tests are performed by local health departments following guidelines set up by the EPA.
The EPA’s “acceptable” level of fecal bacteria is 104 or fewer bacteria colonies per 100 milliliters of water.
If you are not checking this report, you would have no idea which beaches are near closure.
Please note: the Water Quality Monitoring Program does NOT sample in the 48 hours after rainfall of 1/2 inch or more. The reason is that bacteria levels would be very high in nearly every location!
“What Diseases Can I Get in the Chesapeake Bay?”
The most common illness people get from dirty Bay water is diarrhea. Diarrhea can be caused by germs such as Crypto (short for Cryptosporidium), Giardia, Shigella, norovirus and E. coli.
In 2009, the Chesapeake Bay Foundation published, “Bad Water: The Impact on Human Health in the Chesapeake Bay Region”. In it, CBF states, “The Chesapeake Bay in summer is like a warm pond with a broth of nutrients at the right temperature to breed algae and bacteria.”
Vibrio (“Flesh Eating Bacteria”)
“Flesh-eating bacteria,” as Vibrio is sometimes called, consists of several species of Vibrio. Vibrio vulnificus causes severe skin ulcers, gangrene, and deadly blood infections in people who expose cuts to warm saltwater containing the bacteria, as well as diarrheal illnesses in people who eat shellfish infected with Vibrio.
Another species, Vibrio parahaemolyticus, causes diarrhea, vomiting, and skin infections, but is seldom deadly. The best known is Vibrio cholerae which causes cholera. Maryland Healthy Beaches also maintains a nice webpage for Vibrio which can be found here.
The NCCOS publishes a Vibrio map that estimates the areas with highest levels of vibrio bacteria in the water–and forecasts the levels for the next few days. Click this link to view the most up to date map. Note that on this map, some of the highest counts are found just outside Annapolis in the eastern portions of the Severn and south of Annapolis.
Harmful Algal Blooms and Cyanobacteria
One toxin-producing form of algae, called blue-green algae, is not really algae at all. It is actually a class of bacteria called cyanobacteria. There are at least 35 types of algae in the Chesapeake Bay that produce toxins. The most well known, Blue-green (Microcystis), is the cause of most blooms and fish kills reported.
A 2008 study reported that between 2000 and 2006, 31 percent of the waters tested with blue-green algal (cyanobacteria) blooms had enough toxins to make them unsafe for children to swim in.
According to the World Health Organization, Cyanobacterial toxins are classified by how they affect the human body. Swimmers in water containing cyanobacterial toxins may suffer allergic reactions, such as asthma, eye irritation, rashes, and blisters around the mouth and nose.
Mycobacterium marinum (M.Marinum)
This infection can require 6 months of antibiotics. It usually occurs when people swim with an open skin cut. The average time between being in water and showing signs of infection was 21 days (range 5 to 270 days). Also known as “Fish Tank Granulomas,” they are slow growing and can affect the elbows, knees, and backs of feet and hands. The infection can look like either nodules (image left) or shallow ulcers (image right).
A protozoan organism comes from human and animal feces. Unfortunately it is NOT tested for by local health departments.
Cryptosporidium can cause serious diarrhea. In 70% of samples from the Chesapeake Bay (near Baltimore), levels were high enough to infect people, according to Dr. Thaddeus Graczyk, a Johns Hopkins Bloomberg School of Public Health researcher.
Nitrates are compounds found in polluted runoff from farms, lawns, and streets. They can seep into surface and ground water. Drinking water with excessive nitrates may raise the risk of cancer, nervous system deformities in infants and other problems.
“What About People with Younger Children?”
Children can certainly swim in the Chesapeake Bay, but with extra caution. They are at higher risk for ear infections, skin infections and diarrheal illnesses.
Parents know that younger kids are just not as good about avoiding getting water in their mouths. Plus, a young child swallowing a bunch of bacteria is going to be a much bigger dose, relatively speaking, compared to an adult.
“As a parent myself of 2 kids ages 8 and 12, they almost always have some kind of scratch or abrasion on their shins or arms. It’s easy to overlook those open wounds,” says Dr. Michael Freedman of Evolve Medical. “Check them before swimming in the Bay. Open cut or sore? Keep them out or use a really good water-proof bandage.”
“Are Chesapeake Bay Crabs or Fish Safe to Eat?”
If the water isn’t always safe, what about the seafood? Crabs, fish, oysters?
Eating crabs and fish are always ok as long as they are cooked thoroughly. Just remember that after catching fish, they should be kept on ice or refrigerated after being caught. And never put cooked crabs or fish back in the containers they were kept in before cooking.
Note that raw oysters always carry risk, particularly with infections such as Vibrio.
If you have any questions or have been experiencing one of the above symptoms, see your doctor immediately. Evolve Medical is also happy to see you. Same day scheduling on-line here or call 844-322-4222. Or email them at firstname.lastname@example.org.