In the past year, Brazil has seen an unprecedented invasion of Magellanic penguins. The penguins have been washing up on the beaches by the thousands. When they arrive, they are starving and exhausted.
So far, the cause is unknown. The most obvious candidate is climate change, which can affect the circulation of ocean currents. Unfortunately, the effects of climate change on the oceans is not well understood.
"This is extreme, but we don't have statistics on the number of penguins and the ocean temperatures," said José Marengo, a climatologist at Brazil's National Institute for Space Research and a member of the U.N. Intergovernmental Panel on Climate Change. "Some of the most important uncertainties we have are on the oceanic currents."For now, zoos and veterinarians are rehabilitating what penguins they can. Once penguins have recovered, they will be shipped south and sent back out to sea, so that they can find their way back to their normal territories. As long as the cause remains a mystery, however, there is a danger that this phenomenon could cease being an anomaly and become a trend.
There have been other unusual changes in the oceans off Brazil. In 2004, scientists recorded Catarina, the first-ever hurricane generated in the South Atlantic. But only in the last 10 to 15 years have satellites been gathering information on the eddies moving across the Atlantic, and there is not a firm scientific grasp of where and why currents such as the Falkland end, said Antonio Busalacchi, an oceanography and climate expert at the University of Maryland.
"Clearly we've been seeing changes in the ocean circulation in the Southern Hemisphere," he said. "The question for the future, and we don't have an answer yet, is how is that going to shift against the backdrop of climate change?"