Seven years of macroinfauna monitoring at Ladeira beach (Corrubedo Bay, NW Spain) after the Prestige oil spill

Abstract

The exposed sandy beach of Ladeira (Corrubedo Bay, NW Spain) was sampled during seven years (2003–2009) after the Prestige oil spill (winter 2002–03), to determine interannual variations in the macroinfaunal community in two ways: (i) through ecological indices (species richness and abundances, Shannon’s diversity and Pielou’s evenness) and (ii) through the density of the most representative species. A clear zonation pattern was found, consisting of two zones: (i) the supralittoral, occupied by talitrid amphipods, isopods and insects, and (ii) the intertidal, where marine crustaceans and polychaetes prevailed. The amphipods Talitrus saltator and Talorchestia deshayesii dominated from the drift line upwards, and isopods (Eurydice spp.), polychaetes (Scolelepis spp.) and the amphipod Pontocrates arenarius dominated the intertidal. Univariate indices remained constant throughout the study period in the supralittoral, but they varied widely in the intertidal zone. Multivariate analysis showed that the Prestige oil spill scarcely affected the macroinfaunal community structure during the study period (2003–2009) and its effect was limited just to the first campaign (2003), six months after the Prestige accident.