Local diatom species richness of Arctic diatom assemblages from stream scrapes, showing (left) richness as a function of latitude, and (right) site-specific richness. A LOESS smoother (blue line) with a span of 0.75 and a 95% confidence interval (grey shading) was applied to the data (left) to better highlight the general trend. Coloured circles on the map indicate species richness at the sampling sites. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 37 - Figure 4-10

Box-plots of taxa richness (average per lake) by Arctic regions for rotifers (left) and crustaceans (right). Crustacean taxa are restricted to taxa within Calanoida, Cyclopoida and Cladocera. Samples with only a single taxon have been excluded. Boxes represent median and interquartile range. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 60 - Figure 4-27

Results of circumpolar assessment of lake zooplankton, including crustaceans and rotifers, and indicating (a) the location of zooplankton stations, underlain by circumpolar ecoregions; (b) ecoregions with many zooplankton stations, colored on the basis of alpha diversity rarefied to 25 stations; (c) all ecoregions with zooplankton stations, colored on the basis of alpha diversity rarefied to 10 stations; (d) ecoregions with at least two stations in a hydrobasin, colored on the basis of the dominant component of beta diversity (species turnover, nestedness, approximately equal contribution, or no diversity) when averaged across hydrobasins in each ecoregion. State of the Arctic Freshwater Biodiversity Report - Chapter 4- Page 59 - Figure 4-26

Figure 4-1 A generic food web diagram for a lake or river, indicating the basic trophic levels (boxes) and energy flow (arrows) between those levels. Reproduced from Culp et al. (2012a). State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 25 - Figure 4-1

Fish diversity characteristics in three geographical regions: Alaska, Iceland, and Fennoscandia. Gamma diversity is based the total number of species sampled in hydrobasins of each ecoregion. Alpha diversity shows the mean basin species richness (95% confidence interval) and beta diversity shows the component of beta diversity, nestedness or turnover, that dominated within each of the ecoregions; gamma, alpha, and beta diversity estimates were based on a subset of basins where a minimum of 10 stations were sampled. All maps are drawn to the same scale. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 77 - Figure 4-39

Figure 3-3 Long-term trends in total phosphorus water concentrations (μg/L) in four major, unregulated rivers that drain the subarctic Arctic/alpine ecoregion of the Scandinavian peninsula, the Kalix river, The Lule river, the Råne river, and the Torne river. Slopes and p-values are given in the different panels. Boxes indicate medians and 25th and 75th percentiles, while whiskers give the 10th and 90th percentiles. State of the Arctic Freshwater Biodiversity Report - Chapter 3 - Page 21 - Figure 3-3

Figure 3-2 Long-term water temperature trends (1970–2017) for the Utsjoki Nuorgam station in the River Tana (69°N in Finland). The diagram shows the number of days per year with a mean temperature exceeding 5°C. The data show that from 1995 to 2017, this indicator increased by over 0.5 days per year. Data source: Finnish Meteorological Institute. State of the Arctic Freshwater Biodiversity Report - Chapter 3 - Page 15 - Figure 2-1

30-year trends in alpha diversity of benthic macroinvertebrates in the stony littoral zones (1 m depth) of two Scandinavian Arctic/alpine lakes: Lake Abiskojaure (upper panel) and Lake Stor-Tjulträsk (lower panel). State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 71- Figure 4-35

Alpha diversity (± standard error) of river (a) diatoms from benthic samples, (b) benthic macroinvertebrates, and (c) fish within hydrobasins in western and eastern North America plotted as a function of the average latitude in each hydrobasin. Alpha diversity is rarefied to 10 stations per hydrobasin, using size level 5 hydrobasins for all panels. State of the Arctic Freshwater Biodiversity Report - Chapter 5 - Page 85 - Figure 5-2

Although the circumpolar countries endeavor to support monitoring programs that provide good coverage of Arctic and subarctic regions, this ideal is constrained by the high costs associated with repeated sampling of a large set of lakes and rivers in areas that often are very remote. Consequently, freshwater monitoring has sparse, spatial coverage in large parts of the Arctic, with only Fennoscandia and Iceland having extensive monitoring coverage of lakes and streams Figure 6-1 Current state of monitoring for lake FECs in each Arctic country. State of the Arctic Freshwater Biodiversity Report - Chapter 6 - Page 93 - Figure 6-1