Large-Scale Spatial Distribution Patterns of Gastropod assemblages in rocky shores

PATRICIA MILOSLAVICH; JUAN JOSÉ CRUZ-MOTTA; EDUARDO KLEIN; KATRIN IKEN; VANESSA WEINBERGER; BRENDA KONAR; TOM TROTT ; GERHARD POHLE; GREGORIO BIGATTI; LISANDRO BENEDETTI-CECCHI; YOSHIHISA SHIRAYAMA; ANGELA MEAD; GABRIELA PALOMO; MANUEL ORTIZ; JUDITH GOBIN; ADRIANA SARDI; JUAN MANUEL DÍAZ; ANN KNOWLTON; MELISA WONG; ANA C. PERALTA

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2013

1932-6203

Gastropod assemblages from nearshore rocky habitats were studied over global spatialscales to (1) describe broad-scale patterns in assemblage composition, including patternsby feeding modes, (2) identify latitudinal pattern of biodiversity, i.e., richness andabundance of gastropods and/or regional hotspots, and (3) identify potential environmental and anthropogenic drivers of these assemblages. Gastropods were sampled from 45 globally-distributed sites within 12 Large Marine Ecosystem regions (LME) following the NaGISA (Natural Geography in Shore Areas) standard protocol(www.nagisa.coml.org). A total of 393 gastropod taxa from 87 families were collected.Eight of these families (9.2%) appeared in four or more different LMEs. Among these,the Littorinidae was the most widely distributed (8 LMEs) followed by the Trochidae andthe Columbellidae (6 LMEs). In all regions, assemblages were dominated by few species,the most diverse and abundant of which were herbivores. No latitudinal gradients wereevident in relation to species richness or densities among sampling sites. Highest diversity was found in the Mediterranean and in the Gulf of Alaska, while highest densities were found at different latitudes and represented by few species within one genus (e.g. Afrolittorina in the Agulhas Current, Littorina in the Scotian Shelf, and Lacuna in the Gulf of Alaska). No significant correlation was found between species composition and environmental variables (r≤0.355, p>0.05). Contributing variables to this low correlation included invasive species, inorganic pollution, SST anomalies, and chlorophyll-a anomalies. Despite data limitations in this study which restrict conclusions in a global context, this work represents the first effort to sample gastropod biodiversity on rocky shores using a standardized protocol across a wide scale. Our results will generate more work to build global databases allowing for large-scale diversity comparisons of rocky intertidal assemblages.