Amongst surfers, it’s common knowledge that you should stay clear of the ocean after a storm. Why? Because after it rains, the ocean is a supercharged cesspool of sludge.
“The coastal waters are polluted with urban runoff and sewage from leaking waterlogged sewer pipes. In most places, and especially in Southern California, ocean water quality after a rain is dangerous,” writes Chad Nelsen, environmental director of the Surfrider Foundation.
But according to a recent study from the University of Exeter Medical School and Centre for Ecology & Hydrology, the ocean is a dangerous place to swim in no matter what the climate is. “[The study] concluded, compared to non-sea swimmers, the likelihood of developing an earache increases by 77 percent and for a gastrointestinal illness rises by 29 percent,” reported the BBC. Furthermore, one epidemiological study in Santa Monica Bay found that there’s an increased health risk when swimming within 400 yards of a flowing storm drain, reported Beachapedia. (For reference, in Southern California, nearly every stretch of surf is close to a storm drain.)
Scientists measure ocean water quality by taking a water sample 12 to 20 inches from the surface of the ocean. After the sample is taken, it’s placed in a cooler and driven to a nearby lab to be analyzed. “Essentially, you take one bacteria, which is hard to detect, give it food and let it grow into a colony, and then you can count it,” Keith Kezer, program coordinator of the Land and Water Quality Division of San Diego County’s Environmental Health Department, told La Jolla Light. According to the same article, after 16 hours of allowing the bacteria to cultivate, the county decides if the bacterial threshold has been exceeded. If it has, the county will issue a Bacteria Exceedance Advisory.
To that end, there are a number of ocean-related horror stories of surfers and swimmers contracting life-ending infections from the water: In 2015, award-winning surfer Barry Ault contracted a staph infection at Sunset Cliffs in Point Loma, just two days after a rainstorm, reported NBC San Diego. And in 2016, CBS reported that a 67-year-old man died of a flesh-eating bacteria on the eastern shore.
So yes, swimming in the ocean is dangerous, because you might be devoured by sharks or flesh-eating bacteria. But since it’s nearly summer, and there’s only so many skin cancer-inducing tanning sessions you can partake in, frolicking in that deep-blue sea is the cheapest and arguably best way to spend a summer day.
Let’s then turn our focus to the positives, because there are plenty of those, too.
For one, there’s thalassotherapy, which uses seawater as a way of healing. “In 1769, a popular British doctor Richard Russell published a dissertation arguing for using seawater in ‘diseases of the glands,’ in which he included scurvy, jaundice, leprosy and glandular consumption, which was the name for glandular fever at the time. He advocated drinking seawater as well as swimming in it,” reports The Conversation.
According to the same article, the number of minerals in the ocean also works in your favor: “Ocean water differs from river water in that it has significantly higher amounts of minerals, including sodium, chloride, sulphate, magnesium and calcium. This is why it’s highly useful for skin conditions such as psoriasis.”
In 2016, The Daily Mail reported that there’s some evidence that seawater can help treat eczema, due to the moisture-retention quality of magnesium which — as noted above — is a prevalent mineral in ocean water.
Other benefits of thalassotherapy include the fact that it may help increase blood circulation: “Swimming or bathing in warm seawater improves circulation by restoring essential minerals depleted by stress, a poor diet and environmental poisons, according to the Thalasso Experience website,” reported Livestrong.com.
And sure, you could argue that thalassotherapy is a pseudotherapy that’s not backed by actual scientific data. But you could also scroll through pictures of other human beings floating in the ocean being all, like, happy and stuff, and then decide for yourself.