MEPS 515:161-172 (2014)  -  DOI: https://doi.org/10.3354/meps10998

ABSTRACT: The mega-earthquake that occurred in 2010 in central southern Chile produced a coastal uplift of over 3 m in some areas, resulting in the mass mortality of intertidal organisms. At Punta Hualpen, local extinctions of the 2 intertidal bioengineer mussel species Perumitylus purpuratus and Semimytilus algosus occurred as a result of the earthquake. Here we evaluate the ecological recovery capacity of these 2 mussels and explore whether differences in their interspecific competitive abilities may explain the restoration of the vertical distribution of these species during the recovery process. A yearly record of abundance of P. purpuratus and S. algosus in the intertidal zone between 2009 and 2013 indicated that the earthquake had a strong negative impact but that there was a rapid recuperation of the abundance and distributional range of both species over time. Experimental plots in the mid intertidal zone and laboratory experiments showed that S. algosus exhibited lower survival and growth rates in the presence of P. purpuratus. In addition, our results suggest that the recovery of the vertical distributional pattern of intertidal mussel species may be explained by a combination of interference competition caused by crowding behavior at smaller body sizes and competition due to clearance rate efficiency at larger sizes. However, most research has been focused on the description of the effects of mega-scale natural perturbations on marine communities, instead of trying to understand the underlying mechanisms operating in the recovery process.

KEY WORDS: Perumytilus purpuratus · Semimytilus algosus · Earthquake · Intertidal community · Ecological resilience · Chilean coast