Where did all the sardines go?

http://www.salon.com/2015/01/25/where_did_all_the_sardines_go_partner/



The Galapagos archipelago, a breathtakingly beautiful cluster of 19 islands and more than 100 rocks and islets off the coast of mainland Ecuador, was designated a United Nations World Heritage site in 1978. It is home to thousands of animal species that live in, or depend on, the sea. One of the most beloved is the blue-footed booby, known for its brilliant colors and penchant for elaborate dance. Now it appears that the Galapagos may lose its most iconic species. In April 2014, a team of researchers from Wake Forest University announced that blue-footed boobies had nearly stopped breeding, putting the survival of the species in grave danger.

Researchers from University of California reported similar findings about another shorebird 2,000 miles from Galapagos. While conducting a survey of Mexico’s Natural Protected Areas, they discovered that the endangered California brown pelican was largely absent from its primary nesting grounds. Like the boobies, they had nearly stopped breeding. Meanwhile, marine scientists from NOAA had been studying the unprecedented illness of thousands of sea lions on California coastlines.

Are marine animals experiencing a streak of mysterious bad luck? Perhaps. But perhaps it’s not as mysterious as it may seem. Blue-footed boobies, California brown pelicans, sea lions, and a number of other species have something in common: Their natural diet is comprised largely of Pacific sardines, which have suffered the worst population crash since the mid-1900s, leading scientists to posit that the sardine crash may be having widespread impacts on local and migratory species dependent on the Pacific Ocean.

Where did all the sardines go?
In 1948, this question was posed to ocean biologist Ed Rickett, who was investigating the most famous sardine crash in history, which began in 1946. He responded, “They’re in cans!” Today’s scientists don’t think the answer is so simple, as sardine populations are known for following a boom-and-bust cycle. However, they don’t deny that rampant fishing played a significant role in the mid-century crash, and have found that cool water temperatures triggered a natural decline in the 1940s, which was greatly exacerbated by overfishing. It would take four decades for the population to recover from that crash.