A team of geologists attached to the General Secretariat of the Sea (SGM) and biologists from the Spanish Institute of Oceanography (IEO) has discovered a cold-water coral reef more than 800 metres deep in the Cantabrian Sea.

The discovery has occurred during the recent campaign on board the oceanographic vessel Vizconde de Eza, belonging to the General Secretariat of the Sea, and within the framework of the INDEMARES project. The main objective of this project, coordinated by the Biodiversity Foundation, is to contribute to the protection and sustainable use of biodiversity in Spanish seas by identifying areas of value for the Natura 2000 Network.

This discovery is an important achievement for science, since the existence of this type of deep coral reef in Spanish waters was unknown to date. For many years, these ecosystems, with high levels of biodiversity, have been associated with tropical areas with warm and well-lit waters due to their dependence on symbiotic algae.

The development of modern robots and submarines has made it possible to discover coral reefs in cold and deep waters in many areas of the planet, where a multitude of species unknown to science live and which, among many other characteristics, are capable of slowing down climate change by being carbon sinks, reducing the presence of greenhouse gases in the atmosphere.

During this first campaign of the INDEMARES project in the area of influence of the Avilés Canyon, called INDEMARES-AVILÉS 0410, a multidisciplinary team made up of specialists in geology and biology began the first phase of the study aimed at knowing the characteristics of the ecosystems and mapping their habitats and communities. To do this, they used modern technologies, which allow them to obtain valuable data up to 5,000 meters deep.

In this way, an area of more than 6,400 square kilometres has been mapped and in the course of the studies important discoveries were made, such as the existence of a complex and unknown system of tributary canyons to the main axis of the Avilés and which finally pour into the abyssal plain of the Bay of Biscay in a single fan deposit. located at a depth of 4,800 metres.

One of these tributary canyons, 16.5 kilometres long and 6.1 kilometres wide, has unique aspects both in terms of its geological characteristics and current dynamics, as well as for having identified in it and at great depth a remarkable and well-structured reef of cold-water corals.

In order to determine their characteristics, biological samples were taken and dives were carried out with an automaton vehicle equipped with photo and video cameras, which has made it possible to discover that the main structuring species of the reef are the corals Madrepora oculata and Lophelia pertusa, which considerably increase the complexity of the habitat so they are accompanied by other species of gorgonians. antipatharies, glass sponges, echinoderms, king crabs and fish, considerably increasing biodiversity in relation to the rest of the seabeds studied during the campaign.