Seamount physiography and biology in the north-east Atlantic and Mediterranean Sea

Abstract

This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (north-east Atlantic Ocean) and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (north-east Atlantic) and in the Mediterranean Sea is large with around 557 and 101 seamount-like features, respectively. Similarly, seamounts occupy large areas of about 616 000 km² in the OSPAR region and of about 89 500 km² in the Mediterranean Sea. The presence of seamounts in the north-east Atlantic has been known since the late 19th century, but overall knowledge regarding seamount ecology and geology is still relatively poor. Only 37 seamounts in the OSPAR area (3.5% of all seamounts in the region), 22 in the Mediterranean Sea (9.2% of all seamounts in the region) and 25 in the north-east Atlantic south of the OSPAR area have in situ information. Seamounts mapped in both areas are in general very heterogeneous, showing diverse geophysical characteristics. These differences will likely affect the biological diversity and production of resident and associated organisms

Fish Distribution and Habitat Complexity on Banks of the Strait of Sicily (Central Mediterranean Sea) from Remotely-Operated Vehicle (ROV) Explorations

“…: trawling). For this reasons, ROV can be used to explore sensible habitats, filming at dawn and dusk by means of highly sensitive cameras, recording information on geographic position and depth of each observed specimen and, lastly, gathering data for long periods [23]. …”

“…Overall, these environments are poorly investigated owing to difficulties in carrying out scientific surveys and investigations in areas characterized by a rough topography, offshore location, and a strong hydrodynamic regime [22]. Nevertheless, in the last few decades, the employment of increasingly sophisticated remotely operated vehicles (ROV) has allowed to intensify the exploration of banks, including those in the Mediterranean Sea [20,21,22,23,24]. …”

Environmental variability and biodiversity of megabenthos on the Hebrides Terrace Seamount (Northeast Atlantic)

“…Knowledge of seamount ecology in the wider northeast Atlantic is still poor54, but multidisciplinary approaches to collecting these data hold much promise in addressing this gap55. Our first investigation of the turnover in the benthic communities and environmental dynamics at the HTS will contribute to the baseline knowledge needed to monitor this and other seamounts in the northeast Atlantic, while subsequent visual surveys should incorporate detailed acoustic data and broader coverage, particularly of the diverse flank habitats.…”

Persistent Enhancement of Micronekton Backscatter at the Summits of Seamounts in the Azores

“…This region has one of the highest densities of seamounts in the Northeast Atlantic (Morato et al, 2013). Several of these seamounts host commercially valuable pelagic and demersal fish species important for local fisheries (Morato et al, 2008b;Menezes et al, 2013) and act as foraging posts for sea turtles, seabirds, marine mammals, and large pelagic fishes (Santos et al, 2007;Morato et al, 2008b;Silva et al, 2013;Afonso et al, 2014b;Tobeña et al, 2016).…”