Beaches are where the land meets the sea – and where stuff on the land meets the sea. They are usually the easiest way from land to ocean, which means stuff that’s bad on land (like Enterococci Bacteria) often finds its way to the sea by beach. Significant events like heavy tropical rainstorms washes the junk off the land into the sea.
The Department of Planning & Natural in the US Virgin Islands tests beaches weekly and measures levels of Enterococci Bacteria as well as something called ‘Turbidity’ – a measure of water clarity. Most of the time nearly all the beaches are fine – though every week at least one seems to be on the detention list.
This isn’t restricted to the tropics – in Colorado, where I live (for awhile longer), streams and reservoirs are often blacklisted for bacterial misbehavior. At the same time I’m grateful for the measurements. The perfect pairing of Robinson Crusoe and Rachel Carson.