Vacant Bivalve Boreholes Increase Invertebrate Species Richness in a Physically Harsh, Low Intertidal Platform

BAGUR, MARÍA; GUTIÉRREZ, JORGE; ARRIBAS, LORENA; PALOMO, M.

Diversity

MDPI

Año: 2019 vol. 11

Ecosystem engineers can modulate harsh abioticconditions, thus creating habitat for species that cannot withstand the localenvironment. In this study, we investigated if vacant boreholes created by therock-boring bivalve Petricola dactylus increase species richnessin the low intertidal zone of a Patagonian rocky shore characterized by intensehydrodynamic forcing and sediment scour. Invertebrate species richness wasthree times higher in engineered than unengineered habitats (i.e., with andwithout Petricola boreholes, respectively) and the increase inspecies richness was area-independent. The most prevalent species inunengineered areas showed strong adhesion mechanisms, whereas infaunal andvagile species were mostly restricted to boreholes. The positive influence ofengineered microhabitats on species richness can largely be attributed toamelioration of physical conditions, particularly a reduction in hydrodynamic forcesand sediment trapping/stabilization within boreholes. We conclude that vacantboreholes are essential microhabitats for the maintenance of biodiversitywithin the otherwise inhospitable low intertidal zone.