The submarine volcano eruption at the island of El Hierro: physical-chemical perturbation and biological response

Abstract

On October 10 2011 an underwater eruption gave rise to a novel shallow submarine volcano south of the island of El Hierro, Canary Islands, Spain. During the eruption large quantities of mantle-derived gases, solutes and heat were released into the surrounding waters. In order to monitor the impact of the eruption on the marine ecosystem, periodic multidisciplinary cruises were carried out. Here, we present an initial report of the extreme physical-chemical perturbations caused by this event, comprising thermal changes, water acidification, deoxygenation and metal-enrichment, which resulted in significant alterations to the activity and composition of local plankton communities. Our findings highlight the potential role of this eruptive process as a natural ecosystem-scale experiment for the study of extreme effects of global change stressors on marine environments.

A submarine volcanic eruption leads to a novel microbial habitat

“…3). The genome of Thiolava veneris also contains genes involved in different pathways of sulfur metabolism (that is, dissimilatory sulfur oxidation from H 2 S to SO 4 2− and the oxidation of thiosulfate through the sulfur-oxidation (Sox) pathway; Fig. 3).…”

Remote sensing of the El Hierro submarine volcanic eruption plume

“…From November 2011 to March 2012, several cruises were organized by the Instituto Español de Oceanografía (IEO, Spanish Institute of Oceanography) to localize the exact position of the submarine eruption, to perform a periodic bathymetric survey of the area (Rivera et al 2013), and to study the evolution of seawater anomalies produced by changes in physical-chemical parameters (Fraile-Nuez et al 2012;Santana-Casiano et al 2013).…”

“…Observational conditions are improved when the eruption takes places in shallow waters. In these cases, the presence of discoloured waters is frequently observed, and, on occasion, volcanic fragments floating at the surface (Urai and Machida 2005;Mantas, Pereira, and Morais 2011;Shi and Wang 2011;Fraile-Nuez et al 2012;Santana-Casiano et al 2013).…”

“…These effects comprised thermal changes; water acidification; deoxygenation, with oxygen depletion nearing anoxic levels; enhanced light attenuation; discolouration; negative redox potential; pH decrease (from 8 to nearly 5); maximum concentrations of reduced sulphur and total Fe(II) species (200 and 50 µmol kg -1 , respectively); and higher concentrations of dissolved copper, cadmium, lead, and aluminium with maximum values of 6.1, 6.7, 5.8, and 2.122 nanomoles, respectively (FraileNuez et al 2012). In the surrounding area, temperature anomalies were registered of up to 20°C, and the concentration of dissolved gases (CO 2 and SO 2 ) increased several hundred times (Fraile-Nuez et al 2012). The depletion of oxygen was caused by oxidation of reduced gas species such as sulphur and Fe(II) emitted by the volcano (Santana-Casiano et al 2013).…”

Bathymetry of a new-born submarine volcano: El Hierro. Canary Islands

“…Because of the unusual physicochemical conditions of the water column (Fraile-Nuez et al, 2012), as well as the high content of suspended material during Bimbache cruises (Figure 3), acquisition and processing of bathymetric data was slow and laborious. After the return to a period of calm in the eruptive process, and in order to establish the exact bathymetry and morphology of the new volcano, a new geological/hydrographic cruise was carried out in December …”