Functional diversity on rocky shores of the SW Atlantic: sewage effluents influence and mask the effects of the latitudinal gradient

GARAFFO, GV; LLANOS, EN; SARACHO BOTTERO, MA; HINES, E; ELÍAS, R; JAUBET, MML

MARINE ECOLOGY PROGRESS SERIES

INTER-RESEARCH

Año: 2020 vol. 648 p. 39 - 49

0171-8630

Rocky shores are a transitional ecosystem between land and marine environments,and, together with other benthic coastal habitats, have a diverse macrobenthic community.Although there is enough information about the taxonomic diversity of Argentinean rocky shores,studies with a functional approach are scarce. We applied biological traits analysis and functionaldiversity indices to evaluate the geographic variation of the functional diversity of macrobenthicassemblages on rocky shores along a latitudinal gradient in the SW Atlantic (from 37° to 50° S). Atotal of 11 beaches with rocky hard substrate belonging to 2 biogeographical provinces (Magellanicand Argentinean) were studied during April 2016. The trait composition of macrobenthic assemblages and functional diversity indices (Rao?s quadratic entropy) varied significantly along theArgentinean coast, suggesting that the latitudinal gradient influences the distribution of specieswith respect to combinations of trait modalities. Rao?s quadratic entropy, species richness, evenness, and Shannon-Wiener diversity showed a pattern with higher values in the sites located inhigh latitudes. The functional diversity patterns found coincide with the biogeographical provinces. The presence of intertidal sewage effluents considerably influence functional diversity andmask the effects of the latitudinal gradient on the macrobenthic communities on rocky shores.