Don’t needlessly bypass or worry about enjoying some great Malibu beaches because they have had bad beach grades from Heal the Bay (HTB).
This article covers: Under what conditions can HTB beach grades be misleading or helpful? How can you pick a clean beach? How can you lower your risks of getting sick from the waters or sands at any beach?
Fortunately, after years of clean water initiatives by many, the risks of getting sick recreating at Malibu beaches typically trails behind the incidence of going to parties, concerts, schools etc. where ill people can spread contagious germs called pathogens. Shoreline water risks go up significantly when human fecal bacteria contaminate shoreline waters. This has not been the case in Malibu. Bad beach grades here have been attributed to natural sources of relatively harmless bacteria. In recent studies, Malibu’s septic systems have not been the source for high fecal indicator bacteria (FIB) counts and corresponding bad grades at Surfrider, Paradise Cove and Escondido beaches.
The FIB tests are meant for screening purposes mainly, not for the specific detection of disease-causing pathogens and their sources. The validity of the FIB tests is highest when they are used to show long-term trends in order to detect unexpected spikes in counts that require further investigation. Also, routine FIB testing is often not done daily, more typically weekly or monthly. Reports are often delayed by at least 24 hours to weeks when events can easily change water quality.
On the one hand, low FIB counts and A grades can indicate clean water trends except rare times when parasite pathogens are predominant. On the other hand, high FIB counts are often not valid at Malibu beaches and others with unique large natural shorelines and watersheds.
Large numbers of shore birds, sea mammals, soil and sediments, and watershed animals easily account for the high FIB counts. These counts naturally fluctuate depending on where birds, seals or other wildlife and domestic animals have been; as well as whether lagoons and creeks are draining, where and when kelp and algae harboring the bacteria have been transported, and what the tides and currents have done to bring bacteria-laden waters in or out. Also, Malibu’s unique south swell surf resuspends sands containing high FIB counts.
What are the risks from these natural bacteria and other microbes? In our daily lives, we are immersed with millions of bacteria, viruses, parasites, fungi and the like. Most are rarely potential pathogens (human disease causes). In fact, many compete with pathogens and inactivate them or kill them. Some natural source pathogens have been found relatively rarely. Sometimes fecal and Staph bacteria have been attributed to beach goers. The more people the more likely some of them will carry potential pathogens to the beach.
Natural processes help protect us from illness. Sunlight and drying reduce bacteria counts and some pathogens die making the transition to and from fresh and salty waters. Aeration with oxygen from flowing and bubbling water also kills some. The densities and corresponding infection rates of pathogens also fall when they are dispersed in large volumes of water.
You can also make yourself less vulnerable to pathogens. Habits of healthy eating, sleeping and exercise can do wonders to ward off infectious diseases.
To lower your illness risks at any beach simply do the following; learn its local reputation ideally from current studies. If the beach has had consistent A grades, it is likely safe. If it has sporadic bad grades due to natural sources and not high spikes, it is also likely safe; go to the beach after the sun has had several hours to kill off possible pathogens; stay away from actively draining lagoons, storm drains and creeks; shower with soap before and after you go to the beach and encourage others to do the same; avoid beaches where there are or have been large crowds recently; avoid water contact for 72 hours after rain events; if you do get sick, seek medical care for proper diagnosis and care.
To help keep your beach waters clean: pick up the litter, report unnatural water runoff sources that can transport contaminants and don’t let others open creek berms allowing flow to the shoreline. Finally, understand and educate your fellow swimmers, surfers and water enthusiasts about the real limitations of relying on FIB tests as the primary indicators of water quality in Malibu. We don’t want government actions like those taken elsewhere to have dogs chase away coastal birds or tractors to sweep and haul away kelp. More on these related issues next week.
Jeff Harris, M.D., M.P.H.