Fig 1.
Study area with sampling locations (red dots) distributed in three Svalbard fjords: Kongsfjorden, Isfjorden and Hornsund.
Maps were created using the PlotSvalbard R package [10] distributed under the CC BY 4.0 license [10].
Fig 2.
SEM images by PK, of targeted taxa.
Paradexiospira violacea (a); Semibalanus balanoides (b); Harmeria scutulata c).
Fig 3.
Raincloud plot showing Mg-calcite distribution in three Arctic species: barnacle S. balanoides, spirorbis P. violacea and bryozoa H. scutulata. The violin plot represents the probability density function of observations; the black dot is the sample mean alongside the interquartile range (black line). Dot plots display a histogram-like distribution of individual data observations.
Fig 4.
Non-metric multidimensional scaling (NMDS) ordination of skeletal Mg/Ca ratio across species and sampling sites. Each point represents the average Mg/Ca composition for a site, colored by species. Shapes refers to sampling sites, as shown in the legend.
Fig 5.
The violin plots showing spatial variability in Mg/Ca of Harmeria scutulata, Paradexiospira violacea, and Semibalanus balanoides between sampling sites (H2, H3, K1, K2, K3, S1, S2) and along depth (6 m, 12 m).
Each violin plot illustrates the density distribution of Mg/Ca ratios, with boxplots inside indicating the median and interquartile range (IQR). The sample sizes for each plot are showed above each violin.
Table 1.
Pairwise comparisons of significant differences in skeletal Mg/Ca ratios among sampling sites within each species using Kruskal-Wallis post hoc tests.
Fig 6.
Temporal variability in Mg/Ca ratios (mmol/mol) from 2005–2009 for three marine calcifiers H. scutulata, P. violacea and S. balanoides, at Isfjorden.
A) Average Mg/Ca ratio versus year per species. Colored points and trend lines represent different species, as described in the legend. B) Mean annual Mg/Ca versus mean annual sea water temperature per species. Regression lines (linear models) and corresponding statistics (slope, R², p-value) are shown in the top-left corner of each panel.
Fig 7.
Monthly-averaged temperature and light (Lux) variability in Isfjorden between 2006 and 2009. Left panel: Monthly mean temperature (colored line) with minimum and maximum monthly values shown as a shaded blue ribbon. A trend line (red) is included, with slope, R², and p-value displayed in the top-left corner. Right panel: Monthly mean light levels (Lux; brown line) with minimum and maximum monthly values indicated by a shaded yellow ribbon.