The waters of the Pacific off the coast of California are a clear, shimmering blue today, so transparent it’s possible to see the sandy bottom below. Viewing the ocean from the state’s famous craggy headlands, it’s impossible to know that the ocean’s unusual clarity is hiding a cruel beauty: clear water is a sign that the ocean is turning into a desert, and the chain reaction that causes that bitter clarity is perhaps most obvious on the beaches of the Golden State, where thousands of emaciated sea lion pups are stranded. Sea lions are a ubiquitous part of the Californian landscape – they’re up and down beaches, piers and wharfs, with an overall population estimated at around 300,000. They have the Marine Mammal Protection Act of 1972 to thank for their existence, passed by Congress in response to concerns about dwindling populations of marine mammals, including sea lions.

Now, the familiar creatures have become victims of their own success, with some arguing that their population may have reached natural capacity, and others blaming it on changing environmental conditions in California. Over the last three years, the National Oceanic and Atmospheric Administration (NOAA) has noticed a growing number of strandings on the beaches of California and up into the Pacific north-west. In 2013, 1,171 sea lions were stranded, and 2,700 have already stranded in 2015 – a sign that something is seriously wrong, as pups don’t normally wind up on their own until later in the spring and early summer. FULL REPORT