Exceptional discovery of a shallow-water hydrothermal site in the SW area of Basiluzzo islet (Aeolian archipelago, South Tyrrhenian Sea): An environment to preserve

PLoS One. 2018 Jan 4;13(1):e0190710. doi: 10.1371/journal.pone.0190710. eCollection 2018.

Abstract

The geological, biological and geochemical features of a particular field of hydrothermal vents, discovered in the Panarea Volcanic Complex during a research survey carried out in 2015, are described for the first time. The site, located at 70-80 m depth off the South-western coast of the islet of Basiluzzo, was named Smoking Land for the presence of a large number of wide and high active chimneys and was characterized in terms of dissolved benthic fluxes, associated macrofauna and megafauna communities and preliminary mineralogy and geochemistry of chimney structures. On the whole field, a total of 39 chimneys, different in size and shape, were closely observed and described; 14 of them showed emission of low temperature hydrothermal fluids of marine origin characterized by acidified chemical conditions. The CTD and benthic chamber measurements highlighted that the Smoking Land is able to form a sea water bottom layer characterized by variable acidity and high DIC and trace elements concentrations; these characteristics weaken moving away from the chimney mouths. The SEM-EDS analysis of the collected solid samples revealed a chimney structure principally composed by amorphous and low crystalline Fe-oxyhydroxides of hydrothermal origins. The ROV explorations revealed a wide coverage of red algae (Peyssonnelia spp.) colonized by the green algae Flabiella petiolata and by suspension feeders, mainly sponges, but also bryozoans, and tubicolous polychaetes. Although novent-exclusive species were identified, the benthic communities found in association to the chimneys included more taxa than those observed in the surrounding no-vent rocky areas. These first findings evidence a submarine dynamic habitat where geological, chemical and biological processes are intimately connected, making the Smoking Land an important site in terms of marine heritage that should be safeguarded and protected.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bryozoa
  • Chlorophyta
  • Conservation of Natural Resources
  • Hydrogen-Ion Concentration
  • Hydrothermal Vents*
  • Microscopy, Electron, Scanning
  • Oceans and Seas*
  • Porifera
  • Rhodophyta
  • X-Ray Diffraction

Grants and funding

Project financed by D.R.A. Assessorato Territorio Ambiente Regione Siciliana-Asse 3 Linea di intervento 3.2.1.2 of POR FESR Sicilia 2007–2013 (to Valentina Esposito) aimed to assess the marine biodiversity in Sicily with a task WP3.2 focused on hydrothermal systems. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.