RECOVERY AND GENETIC DIVERSITY OF THE INTERTIDAL KELP LESSONIA NIGRESCENS (PHAEOPHYCEAE) 20 YEARS AFTER EL NINO 1982/831

摘要: Massive mortality in kelp beds of the Pacific coasts North and South America was caused by rise surface seawater temperature during El Nino Southern Oscillation (ENSO) event 1982/83, strongest four half previous centuries. In northern Chile a stretch 600 km coastline showed massive intertidal species Lessonia nigrescens Bory, which only few individuals managed to survive. Kelps their associated biodiversity recovered but recolonization general variable time space seemingly very slow along Chilean coasts. Here we show, effectively, that northward advanced less than 60 20 years. Conversely, Northern Hemisphere 300 six months after same ENSO event. Genetic diversity two most affected populations L. shows heterozygosity polymorphism with respect observed non populations. addition, geographically separated seem highly isolated as evidenced high significant fixation indices (all F S T values over 0.4).