Cold-water corals in the Mediterranean: a history of discovery

Abstract

The earliest records of cold-water corals from the Mediterranean Sea date back to the eighteenth century when Linnaeus first described Madrepora oculata based on specimens from the central Mediterranean and Tyrrhenian Sea. It was only towards the end of the nineteenth century that cold-water corals were recorded from elsewhere in the Mediterranean, thanks to early research cruises that explored the Mediterranean deep-sea benthos. Although the first records of live cold-water corals date back to the early twentieth century, further observations of living individuals were extremely rare and most records made by the end of the century were actually based on dead or fossil fragments. This led to the idea that extant Mediterranean cold-water coral assemblages are merely relicts of the communities that thrived during the Pleistocene. However, several sites with live frameworkforming cold-water coral species were discovered since the year 2000, including six regions identified as coldwater coral provinces given that they support a dense growth of living corals. The emerging picture is that thriving cold-water coral assemblages that are hotspots of deep-sea biodiversity still occur in the Mediterranean, but have a rather punctuate distribution along the circulation path of the Levantine Intermediate Water, which appears to be a main driver for cold-water coral distribution in the Mediterranean.