First Macro-Colonizers and Survivors Around Tagoro Submarine Volcano, Canary Islands, Spain

The influence of the degassing phase of the Tagoro submarine volcano (Canary Islands) on the metal content of three species of cephalopods

Underwater volcanic eruptions are a type of natural contamination that affect all marine organisms at a local level. These eruptions usually begin and end a degassing stage of the volcano that, although they do not affect the magnitude of magma emanation, affect organisms to a lesser degree locally, such as cephalopods that due to their metabolism and trophic level, are good bioindicators of contamination. A total of 180 samples of three species of cephalopods were collected for the study: sixty Sepia officinalis, sixty Octopus vulgaris and sixty Loligo vulgaris in the area of the submarine volcano in El Hierro, Tenerife and Lanzarote in the Canary Islands (twenty samples per species in each location), and the metal concentrations (Al, Cd, Cr, Cu, Fe, Li, Ni, Pb and Zn) in each of the samples were analyzed. All species showed significant differences for all metals in El Hierro compared to Tenerife and Lanzarote. All the analyzed species from El Hierro had higher concentrations of the nine studied metals, this is due to the fact that they were caught near the Tagoro submarine volcano, which at the time was in a state of degassing and discharged many metal-rich compounds.

Offshore Neopycnodonte Oyster Reefs in the Mediterranean Sea

Oysters are important ecosystem engineers best known to produce large bioconstructions at shallow depth, whilst offshore deep-subtidal oyster reefs are less widely known. Oyster reefs engineered by Neopycnodonte cochlear (family Gryphaeidae) occur at various sites in the Mediterranean Sea, between 40 and 130 m water depths. Remotely Operated Vehicle surveys provide new insights on this rather neglected reef types with respect to their shape, dimensions and associated biodiversity. We suggest that these little contemplated reefs should be taken in due consideration for protection.