Coastal habitats as surrogates for taxonomic, functional and trophic structures of benthic faunal communities

PLoS One. 2013 Oct 22;8(10):e78910. doi: 10.1371/journal.pone.0078910. eCollection 2013.

Abstract

Due to human impact, there is extensive degradation and loss of marine habitats, which calls for measures that incorporate taxonomic as well as functional and trophic aspects of biodiversity. Since such data is less easily quantifiable in nature, the use of habitats as surrogates or proxies for biodiversity is on the rise in marine conservation and management. However, there is a critical gap in knowledge of whether pre-defined habitat units adequately represent the functional and trophic structure of communities. We also lack comparisons of different measures of community structure in terms of both between- (β) and within-habitat (α) variability when accounting for species densities. Thus, we evaluated a priori defined coastal habitats as surrogates for traditional taxonomic, functional and trophic zoobenthic community structure. We focused on four habitats (bare sand, canopy-forming algae, seagrass above- and belowground), all easily delineated in nature and defined through classification systems. We analyzed uni- and multivariate data on species and trait diversity as well as stable isotope ratios of benthic macrofauna. A good fit between habitat types and taxonomic and functional structure was found, although habitats were more similar functionally. This was attributed to within-habitat heterogeneity so when habitat divisions matched the taxonomic structure, only bare sand was functionally distinct. The pre-defined habitats did not meet the variability of trophic structure, which also proved to differentiate on a smaller spatial scale. The quantification of trophic structure using species density only identified an epi- and an infaunal unit. To summarize the results we present a conceptual model illustrating the match between pre-defined habitat types and the taxonomic, functional and trophic community structure. Our results show the importance of including functional and trophic aspects more comprehensively in marine management and spatial planning.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aquatic Organisms / classification
  • Aquatic Organisms / physiology*
  • Biodiversity*
  • Ecosystem*
  • Food Chain*
  • Humans

Grants and funding

Financial support was received from Maj and Tor Nessling Foundation (Project no. 2010127 and 2011079) and Stiftelsen för Åbo Akademi. Research presented in this paper contributes to the Nordic Centre for Research on Marine Ecosystems and Resources under Climate Change (NorMER), which is funded by the Norden Top-level Research Initiative sub-programme “Effect Studies and Adaptation to Climate Change.” The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.