Large-scale spatial distribution patterns of gastropod assemblages in rocky shores

PLoS One. 2013 Aug 13;8(8):e71396. doi: 10.1371/journal.pone.0071396. eCollection 2013.

Abstract

Gastropod assemblages from nearshore rocky habitats were studied over large spatial scales to (1) describe broad-scale patterns in assemblage composition, including patterns by feeding modes, (2) identify latitudinal pattern of biodiversity, i.e., richness and abundance of gastropods and/or regional hotspots, and (3) identify potential environmental and anthropogenic drivers of these assemblages. Gastropods were sampled from 45 sites distributed 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 and the Columbellidae (6 LMEs). In all regions, assemblages were dominated by few species, the most diverse and abundant of which were herbivores. No latitudinal gradients were evident 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biodiversity
  • Ecosystem*
  • Environment*
  • Gastropoda*
  • Oceanography
  • Population Density
  • Population Dynamics
  • Spatial Analysis

Grants and funding

Funding was provided by multiple sources, including the Alfred P. Sloan Foundation through the NaGISA project, the History of the Near Shore (HNS) program, the History of Marine Populations (HMAP), Fisheries and Oceans Canada (DFO), Suffolk University, the Gulf of Maine (GoMA) project, Chevron-Venezuela, Decanato de Investigación y Desarrollo – Universidad Simón Bolívar, Exxon Valdez Oil Spill Trustee Council - Gulf Ecosystem Monitoring, SAEON (South African Environmental Observation Network), and SANCOR Seachange Program and the Centre for Invasion Biology (CIB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.