Rocky intertidal zonation pattern in Antofagasta, Chile: invasive species and shellfish gathering

Biological invasions affecting rocky intertidal zonation patterns, communities and/or food-webs, yield information on species interactions and help in understanding ecosystem functioning. In the Bay of Antofagasta, northern Chile, the non-indigenous barrel-shaped tunicate Pyura praeputialis, originally from Australia, has invaded (in the past century or so) and monopolized a major portion of the mid-intertidal rocky shore, displacing upshore the ecological center of the native dominant mussel P. purpuratus. Unlike in Australia, in Antofagasta the sea squirt is consumed and subjected to intensive artisan exploitation. Long-term monitoring protocols show that in the past 10 years Antofagasta’s tunicate population has experienced a drastic decline, affecting the intertidal zonation pattern and that at the same time a deterioration of ecosystem services has occurred.