Marine Environment Around Iceland: Hydrography, Sediments and First Predictive Models of Icelandic Deep-sea Sediment Characteristics

Abstract

Sediment samples and hydrographic conditions were studied at 28 stations around Iceland. At these sites, Conductivity−Temperature−Depth (CTD) casts were con− ducted to collect hydrographic data and multicorer casts were conducted to collect data on sediment characteristics including grain size distribution, carbon and nitrogen concentra− tion, and chloroplastic pigment concentration. A total of 14 environmental predictors were used to model sediment characteristics around Iceland on regional scale. Two approaches were used: Multivariate Adaptation Regression Splines (MARS) and randomForest regres− sion models. RandomForest outperformed MARS in predicting grain size distribution. MARS models had a greater tendency to over− and underpredict sediment values in areas outside the environmental envelope defined by the training dataset. We provide first GIS layers on sediment characteristics around Iceland, that can be used as predictors in future models. Although models performed well, more samples, especially from the shelf areas, will be needed to improve the models in future.

A Multi-gene Analysis Reveals Multiple Highly Divergent Lineages of The Isopod Chelator Insignis (Hansen, 1916) South of Iceland

“…As desmosomatid distribution is linked to the water masses around Iceland (Brix and Svavarsson 2010), we might hypothesize that the depth gradient in the stations of the present study (areas 1, 6, 7, 9 and 10) may correlate with different water masses. According to the CTD profiles from IceAGE1 (Ostmann et al 2014;Sa− rah Schnurr, pers. comm.…”

“…2; Meißner et al 2013, fig. 2;Ostmann et al 2014). South of Iceland, the Reykjanes Ridge separates the eastern deep areas of the Ice− land Basin and the western deep areas of the Irminger Basin (Fig.…”

Amphipod family distributions around Iceland

“…A similar pattern was observed for the anthuridean isopod Calathura brachiata (Stimpson, 1853) (Negoescu and Svavarsson 1997). This distribution can be linked to the warm surface current (North Atlantic Current) that comes from the south, in the Iceland Basin, divides, with one branch flowing around the Faroe islands, and the second branch encircling Iceland along its south and west coast (Ostmann et al 2014). The subcluster A2 groups deeper stations from the Iceland and Irminger basins, separated by the Reykjanes Ridge.…”

“…The lack of a barrier effect has already been observed for other peracarids, including Amphipoda (Svavarsson 1997, Negoescu and Svavarsson 1997, Brix et al 2014b, Jazdzewska et al 2018). In the case of subcluster A2 (see Figure 9), the Iceland Scotland Overflow Water, which is a deep-water, cold current moving from north east into the Iceland Basin and later flowing along the Reykjanes Ridge into the Irminger Basin seems to be responsible for shaping the observed assemblage (Ostmann et al 2014). Finally, the third group recognised consists of deep (middle and deep bathyal) samples from the Norwegian Sea and the east Faroe Islands and may be associated with cold Norwegian Sea deep water (Ostmann et al 2014).…”

Preface—biodiversity of Icelandic waters

“…Various gears for the collection of benthic fauna were used and accompanied by the measurement of abiotic parameters of near-bottom water by means of a conductivity-temperature-depth sensor (CTD). A map indicating the location of sampling stations for different gears is provided by Ostmann et al 2014 andMeißner et al 2014 (also see Fig. 1).…”