Effects of rocky shore coseismic uplift and the 2010 Chilean mega-earthquake on intertidal biomarker species

The devastating earthquake (moment magnitude: 8.8 MW) that struck Chile on 27 February 2010 and the following tsunami waves produced widespread damage, coastal coseismic uplifts, and large-scale mortality of rocky intertidal and shallow subtidal organisms. The effects were particularly remarkable around the Gulf of Arauco, Santa Mar a Island and the Bay of Concepcion (similar to 36 to 38 degrees S). Measurements of rocky intertidal and shallow subtidal belt-forming (biomarker) species conducted a few weeks after the earthquake indicated coastal uplifts ranging from similar to 0.2 to 3.1 m, which are similar to uplifts estimated by FitzRoy (1839; Voyages of the Adventure and Beagle, Vol. II) and Darwin (1839; Voyages of the Adventure and Beagle, Vol. III) after the 1835 Chilean earthquake. In major uplifted sites, there was massive mortality of the main intertidal and shallow subtidal belt-forming species, such as lithothamnioid melobesioid coralline algae, brown kelps and mussels, and dramatic changes in the marine rocky intertidal ecosystem. We suggest that in the southeastern Pacific, drastic and rapid coastal deformations seriously impinge on rocky shore populations, communities and ecosystems and may have significance for management and conservation practices, as for example in connection with alterations of parental stocks and recruitment rates.