ALBERT

Description: Microfaunal assemblages of benthic foraminifera, ostracods, and tintinnids from two marine sediment cores retrieved from the Herschel Basin of the Canadian Beaufort Sea shelf document relationships with environmental parameters such as salinity, sea-ice cover, and turbulence. Cores YC18-HB-GC01 and PG2303-1 were collected at 18 and 32 m water depth, respectively. At these sites, sediment accumulation rates range between 0.6 and 1.7 cm yr–1 allowing a near-annual temporal resolution over the last 50 years. Multivariate analyses indicate that benthic foraminiferal assemblages respond primarily to food supply. Dissimilarities between the microfaunal assemblages of the two cores are mainly the result of bottom water salinity levels linked to water depth. High abundance of the benthic foraminiferal species Elphidium clavatum and occurrences of Elphidium bartletti point to varying, but relatively low, salinities at the shallow core site YC18-HB-GC01, which may be affected by variations in the summer halocline depth. Higher species diversity and more abundant Cassidulina reniforme and Stainforthia feylingi characterize the deeper core PG2303-1, which might reflect more stable conditions and higher bottom-water salinities throughout the studied time interval. The most important microfaunal shift of the last 50 years, observed in the shallower longer core YC18-HB-GC01, occurred at the turn of the 21st century. Prior to ∼2000 CE, the presence of Islandiella norcrossi indicates more stable and saline conditions. Since ∼2000 CE, increased abundances of Haynesina nivea and of the ciliate Tintinnopsis fimbriata suggest decreased salinity and increased turbidity. An increased abundance of Eoeponidella pulchella after ∼2000 CE suggests a concurrent increase in productivity in the last two decades. This shift is nearly synchronous with a decrease in mean summer sea-ice concentration, which can play an important role in bottom water stability on the shelf. Easterly winds can induce a reduction in the sea-ice cover, but also foster a westward spreading of the Mackenzie River plume and the upwelling of nutrient-rich Pacific waters onto the shelf. Both factors would explain the increased freshening and productivity of the Herschel Basin. The last two decades were also marked by a decrease in ostracod abundance that may relate to higher water turbidity. This study shows that combining information from benthic foraminifera, ostracods, and tintinnids provides a comprehensive insight into recent hydrographic/climatic changes in nearshore Arctic habitats, where productivity is critical for the food security of local communities.

Description: This is a hydrographic dataset containing CTD cast and rosette bottle data from two consecutive cruises (NEG2017 and NorthGreen) on the research vessel RV Dana between 23-08-2017 and 01-10-2017 of 2017 on the Northeast Greenland shelf. Both cruises took place between 73.3197 to 80.0519 latitude and 2.1011 to 21.2039 longitude (decimal). The NEG2017 cruise took place from 23 August 2017 to 11 September 2017 was part of the Strategic Environmental program for Northeast Greenland with as its goal to provide environmental impact information pertaining to potential oil exploitation and oil spill response activities in the region. The cruise leader for NEG2017 was Eva Friis Møller. The NorthGreen2017 cruise took place directly after the first between 11 September 2017 and 1 October 2017. It aimed to collect data pertaining to hydroraphical and environmental changes on the shelf. The cruise leader for the NorthGreen2017 cruise was Marit-Solveig Seidenkrantz.

Description: The NEG2017 cruise took place from 23 August 2017 to 11 September 2017 was part of the Strategic Environmental program for Northeast Greenland with as its goal to provide environmental impact information pertaining to potential oil exploitation and oil spill response activities in the region. The cruise leader for NEG2017 was Eva Friis Møller.

Description: The NorthGreen2017 cruise took place directly after the first between 11 September 2017 and 1 October 2017. It aimed to collect data pertaining to hydroraphical and environmental changes on the shelf. The cruise leader for the NorthGreen2017 cruise was Marit-Solveig Seidenkrantz.

Description: The NorthGreen2017 cruise took place directly after the first between 11 September 2017 and 1 October 2017. It aimed to collect data pertaining to hydroraphical and environmental changes on the shelf. The cruise leader for the NorthGreen2017 cruise was Marit-Solveig Seidenkrantz.

Description: The NEG2017 cruise took place from 23 August 2017 to 11 September 2017 was part of the Strategic Environmental program for Northeast Greenland with as its goal to provide environmental impact information pertaining to potential oil exploitation and oil spill response activities in the region. The cruise leader for NEG2017 was Eva Friis Møller.

Description: The data published here were gathered in the framework of a multi-proxy-based study of paleotemperature (both marine and terrestrial), -salinity, and -ecosystem changes from the Little Belt (Site M0059). They cover the past ~8,000 years and contain only material from the uppermost subunits 1a and 1b encountered at Site M0059 (see e.g. Andrén et al. 2015). Four environmental zones (EZ1: oldest, freshwater conditions; EZ2 to EZ4 reflecting following salinity and ecosystem changes in the region) were identified in Kotthoff et al. (2017). The age model and the sedimentology are discussed in Kotthoff et al. (2017). The datasets comprise data for salinity proxies (diatoms, aquatic palynomorphs, diol index) and for water temperature proxies (foraminiferal Mg/Ca-ratios, long chain diol index and TEXL86) as well as temperature reconstruction based on pollen grains. It is discussed in Kotthoff et al. (2017) that applying and interpreting proxies in coastal environments and marginal seas needs particular caution. For example, foraminiferal Mg/Ca-ratios may have been influenced by contamination by authigenic coatings in the deeper intervals of the record. Lipid paleothermometers were probably influenced by significant changes in depositional settings in the Little Belt. References: Andrén, T., Jørgensen, B.B., Cotterill, C., and the Expedition 347 Scientists: Baltic Sea Paleoenvironment. Proceedings IODP, 347. College Station, TX (Integrated Ocean Drilling Program), https://doi.org/10.2204/iodp.proc.347.101.2015, 2015. Kotthoff, U., Groeneveld, J., Ash, J. L., Fanget, A.-S., Krupinski, N. Q., Peyron, O., Stepanova, A., Warnock, J., Van Helmond, N. A. G. M., Passey, B. H., Clausen, O. R., Bennike, O., Andrén, E., Granoszewski, W., Andrén, T., Filipsson, H. L., Seidenkrantz, M.-S., Slomp, C. P., and Bauersachs, T.: Reconstructing Holocene temperature and salinity variations in the western Baltic Sea region: a multi-proxy comparison from the Little Belt (IODP Expedition 347, Site M0059), Biogeosciences, 14, 5607–5632, https://doi.org/10.5194/bg-14-5607-2017, 2017.

Description: Benthic foraminifera assemblage data for marine sediment core DA17-NG-ST03-039G retrieved in the Westwind Trough on the Northeast Greenland Shelf. The marine gravity core was collected during the NorthGreen2017 cruise on board the research vessel RV Dana. The data covers the period 13.3 to 3.9 cal ka BP. The benthic foraminifera assemblage data was carried out in order to reconstruct the oceanographic development on the Northeast Greenland shelf.