A cart of deceased malnourished and dehydrated sea lions that had been stranded along the northern California coast, await their turn for necropsy. Photograph: Peter Dasilva/EPA
May 2015 – OCEAN HEALTH – 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. The problem, explains Justin Viezbicke of NOAA, is those crystal-clear waters. “The main contributing factor that we’re looking at right now and talking about with the biologists and climatologists on the Channel Islands [a major sea lion rookery] is the lack of upwelling. We haven’t had the strong north winds that drive the currents that create it, and because it hasn’t materialized – it’s moved the prey further and deeper from the moms that are foraging.” –Guardian
Nate Mantua, NOAA: “[An unusually large number of sea lions stranding in 2013 was a red flag] there was a food availability problem even before the ocean got warm.” Johnson: This has never happened before… It’s incredible. It’s so unusual, and there’s no really good explanation for it. There’s also a good chance that the problem will continue, said a NOAA research scientist in climatology, Nate Mantua.
Experts blame a lack of food due to unusually warm ocean waters. NOAA declared an El Nino, the weather pattern that warms the Pacific, a few weeks ago. The water is three and a half to six degrees warmer than the average, according to Mantua, because of a lack of north wind on the West Coast. Ordinarily, the north wind drives the current, creating upwelling that brings forth the nutrients that feed the sardines, anchovies and other fish that adult sea lions feed on. –ERN