Mapping cold-water coral habitats at different scales within the Northern Ionian Sea (Central Mediterranean): an assessment of coral coverage and associated vulnerability

PLoS One. 2014 Jan 23;9(1):e87108. doi: 10.1371/journal.pone.0087108. eCollection 2014.

Abstract

In this study, we mapped the distribution of Cold-Water Coral (CWC) habitats on the northern Ionian Margin (Mediterranean Sea), with an emphasis on assessing coral coverage at various spatial scales over an area of 2,000 km(2) between 120 and 1,400 m of water depth. Our work made use of a set of data obtained from ship-based research surveys. Multi-scale seafloor mapping data, video inspections, and previous results from sediment samples were integrated and analyzed using Geographic Information System (GIS)-based tools. Results obtained from the application of spatial and textural analytical techniques to acoustic meso-scale maps (i.e. a Digital Terrain Model (DTM) of the seafloor at a 40 m grid cell size and associated terrain parameters) and large-scale maps (i.e. Side-Scan Sonar (SSS) mosaics of 1 m in resolution ground-truthed using underwater video observations) were integrated and revealed that, at the meso-scale level, the main morphological pattern (i.e. the aggregation of mound-like features) associated with CWC habitat occurrences was widespread over a total area of 600 km(2). Single coral mounds were isolated from the DTM and represented the geomorphic proxies used to model coral distributions within the investigated area. Coral mounds spanned a total area of 68 km(2) where different coral facies (characterized using video analyses and mapped on SSS mosaics) represent the dominant macro-habitat. We also mapped and classified anthropogenic threats that were identifiable within the examined videos, and, here, discuss their relationship to the mapped distribution of coral habitats and mounds. The combined results (from multi-scale habitat mapping and observations of the distribution of anthropogenic threats) provide the first quantitative assessment of CWC coverage for a Mediterranean province and document the relevant role of seafloor geomorphology in influencing habitat vulnerability to different types of human pressures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anthozoa / physiology*
  • Data Collection
  • Ecosystem*
  • Environmental Monitoring*
  • Mediterranean Sea
  • Seawater*
  • Video Recording

Grants and funding

The data were collected and analysed within the framework of the EU FP7 project CoralFish (Ecosystem-based management of corals, fish and fisheries in the deep waters of Europe and beyond, Grant agreement number: 213144 - www.eu-fp7-coralfish.net) and the National project MAGIC (Mapping Geohazard along the Italian Coasts – www.magicproject.it). ROV video footage were collected within the framework of the CoNISMa project RBAU 01RKC7_004 APLABES (2004-2006FIRB program) and of the EU FP6 project HERMES (Hotspot Ecosystem Research on the Margins of European Seas, Contract number GOCE-CT-2005-511234). The authors’ work also benefited from the RITMARE project, funded by the Italian Ministry of University and Research (MIUR), the ESF COCARDE Network, and the Hessian initiative for the development of scientific and economic excellence (LOEWE) at the Biodiversity and Climate Research Centre (BiK-F), Frankfurt, Germany. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.