The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount) is described using Remotely Operated Vehicle (ROV) video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i) the top shows a dense covering of the kelp Laminaria ro...

Here we present first observations, from instrumentation installed on moorings and a float, of unexpectedly low (< 2 μmolkg) oxygen environments in the open waters of the tropical North Atlantic, a region where oxygen concentration does normally not fall much below 40 μmolkg. The low-oxygen zones are created at shallow depth, just below the mixed layer, in the euphotic zone of cyclonic eddies a...

The composition of prokaryotic communities was determined in the meso- and bathypelagic waters funneled through the Romanche Fracture Zone (RFZ, 2°7'S, 31°79'W to 0°6'N, 14°33'W) in the tropical Atlantic. Distinct water masses were identified based on their physical and chemical characteristics. The bacterial and archaeal communities were depth-stratified with a total of 116 and 25 operational ...

Sinking organic matter in the North Atlantic Ocean transfers 1–3 Gt carbon yr from the surface ocean to the interior. The majority of this exported material is thought to be in form of large, rapidly sinking particles that aggregate during or after the spring phytoplankton bloom. However, recent work has suggested that intermittent water column stratification resulting in the termination of dee...

The inventories of carbon residing in organic matter dissolved in the ocean [dissolved organic carbon (DOC)] and in the atmosphere as CO2 are of the same order of magnitude, such that small changes in the DOC pool could have important consequences in atmospheric carbon and thus climate. DOC in the global ocean is largely formed in the sunlit euphotic zone, but identifying predictable controls o...

The bearded fireworm Hermodice carunculata is widely distributed across tropical and subtropical Atlantic Mediterranean Oceans was previously considered to be mostly associated with shallow reefs. We provide here data on the distribution, abundance habitat use of H. a euphotic-mesophotic gradient (0-90 m) in Saint Peter Paul’s Archipelago (SPSPA, Mid Ridge, Brazil). Samples were obtained using ...

Mesoscale eddies have been shown to be a common feature of open ocean regions such as the Sargasso Sea. By lifting nutrients up to the lower portions of the euphotic zone, these eddies can cause episodic phytoplankton blooms that can lead to substantial new production. In the Sargasso Sea, it has been estimated that such blooms can account for 35%–50% of annual new production. In the present st...

the qom formation in naragh area, with 185 meter thickness, is exposed about 25 km northeast of delijan. this formation in the studied area, lithologically, consists of shale, gravely limestone, and sandy limestone, with thin, medium to thick bedded and massive limestons. it disconformably covers the lower red formation and is covered by recent alluvium. in this research, the role of large fora...