Magnetic susceptibility and ice-rafted debris in surface sediments of the Nordic Sea

Magnetic susceptibility and ice-rafted debris of surface sediments in the Nordic Seas were investigated to reconstruct source areas and recent transport pathways of magnetic minerals. From the distribution of magnetic susceptibility and ice-rafted debris and published data on petrographic tracers for iceberg drift, we reconstructed a counter-clockwise iceberg drift pattern during cooler phases in the Holocene, which is similar to conceptual and numerical models for Weichselian iceberg drift. The release of basaltic debris at Scoresby Sund played a significant role for the magnetic signature of stadial/interstadial events during isotope stage 3 recorded in sediment cores of the Nordic Seas.

Abundance, biomass and secondary production of benthic megafauna on the Barents Sea shelf in 2008 and 2009

Megabenthos plays a major role in the overall energy flow on Arctic shelves, but information on megabenthic secondary production on large spatial scales is scarce. Here, we estimated for the first time megabenthic secondary production for the entire Barents Sea shelf by applying a species-based empirical model to an extensive dataset from the joint Norwegian? Russian ecosystem survey. Spatial patterns and relationships were analyzed within a GIS. The environmental drivers behind the observed production pattern were identified by applying an ordinary least squares regression model. Geographically weighted regression (GWR) was used to examine the varying relationship of secondary production and the environment on a shelfwide scale. Significantly higher megabenthic secondary production was found in the northeastern, seasonally ice-covered regions of the Barents Sea than in the permanently ice-free southwest. The environmental parameters that significantly relate to the observed pattern are bottom temperature and salinity, sea ice cover, new primary production, trawling pressure, and bottom current speed. The GWR proved to be a versatile tool for analyzing the regionally varying relationships of benthic secondary production and its environmental drivers (R² = 0.73). The observed pattern indicates tight pelagic? benthic coupling in the realm of the productive marginal ice zone. Ongoing decrease of winter sea ice extent and the associated poleward movement of the seasonal ice edge point towards a distinct decline of benthic secondary production in the northeastern Barents Sea in the future.

Registry of all stations from the Tara Oceans Expedition (2009-2013)

The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data set is a registry of all stations conducted during the Tara Oceans Expedition (2009-2013). The registry provides details about the scientific interest of each station, including (1) the geographic context, (2) legal context, (3) the environmental features that were targeted, and (4) a detailed account of devices deployed during the station. Uniform resource locators (URLs) offer direct links to the corresponding (1) physical oceanographic context reports, (2) list of samples collected during the station, (3) environmental data published at PANGAEA, and (4) nucleotides data published at the European Nucleotides Archive (EBI-ENA).

Physical oceanography from CTD during Maria S. Merian cruise MSM20/4 in spring 2012

With an extension of > 40 km**2 the recently discovered Campeche cold-water coral province located at the northeastern rim of the Campeche Bank in the southern Gulf of Mexico belongs to the largest coherent cold-water coral areas discovered so far. The Campeche province consists of numerous 20-40 m-high elongated coral mounds that are developed in intermediate water depths of 500 to 600 m. The mounds are colonized by a vivid cold-water coral ecosystem that covers the upper flanks and summits. The rich coral community is dominated by the framework-building Scleractinia Enallopsammia profunda and Lophelia pertusa, while the associated benthic megafauna shows a rather scarce occurrence. The recent environmental setting is characterized by a high surface water production caused by a local upwelling center and a dynamic bottom-water regime comprising vigorous bottom currents, obvious temporal variability, and strong density contrasts, which all together provide optimal conditions for the growth of cold-water corals. This setting - potentially supported by the diel vertical migration of zooplankton in the Campeche area - controls the delivering of food particles to the corals. The Campeche cold-water coral province is, thus, an excellent example highlighting the importance of the oceanographic setting in securing the food supply for the development of large and vivid cold-water coral ecosystems.