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El Niño affects coral for years

It took coral in northern Bahia 13 years to recover from the El Niño of 1997–98

Francisco KelmoIt took coral in northern Bahia 13 years to recover from the El Niño of 1997–98Francisco Kelmo

More than a decade was needed for banks of coral reefs in northern Bahia to completely overcome the negative effects caused by the largest El Niño in recent times, which occurred between 1997 and 1998, and return to the same levels of biodiversity as before. “We had no idea that it would take 13 years to recover,” says biologist Francisco Kelmo of the Federal University of Bahia (UFBA), author of the study along with Martin J. Attrill of the University of Plymouth, England (PLoS One, May 31, 2013). The researchers monitored the conditions of eight coral species found in the shallow reef banks at four sites in the region (Praia do Forte, Itacimirim, Guarajuba and Abaí) between 1995 and 2011. Caused by the abnormal warming of waters in the South Pacific, El Niño causes changes in rainfall and drought patterns and also affects atmospheric temperature in various regions of the globe. In the Northeast, it often intensifies the dry season and the heat. Climate changes favor the occurrence of the phenomenon called bleaching, easily identifiable because it makes corals become paler, possibly causing their death. During the monitoring period, all coral species showed high rates of mortality and one, Porites astreoides, disappeared entirely from the reefs for over seven years, from 2000 to 2007.