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 6-2 Current state of monitoring for river FECs in each Arctic country State of the Arctic Freshwater Biodiversity Report - Chapter 6 - Page 94 - Figure 6-2

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

Summary of the taxa accounting for 85% of the lake littoral benthic macroinvertebrates collected in each of several highly-sampled geographic areas, with taxa grouped by order level or higher in pie charts placed spatially to indicate sampling area. Pie charts correspond to (1) Alaska, (2) Greenland low Arctic, (3) Iceland, and (4) Fennoscandia. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 69 - Figure 4-33

Box plot represents the homogeneity of assemblages in high Arctic (n=190), low Arctic (n=370) and sub-Arctic lakes (n=1151), i.e., the distance of individual lake phytoplankton assemblages to the group centroid in multivariate space. The mean distance to the centroid for each of the regions can be seen as an estimated of beta diversity, with increasing distance equating to greater differences among assemblages. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 48 - Figure 4-18

Figure 4 17 Results of circumpolar assessment of lake phytoplankton,(a) the location of phytoplankton stations, underlain by circumpolar ecoregions; (b) ecoregions with many phytoplankton stations, colored on the basis of alpha diversity rarefied to 35 stations; (c) all ecoregions with phytoplankton 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 56 - Figure 4-17

Results of circumpolar assessment of river benthic macroinvertebrates, indicating (a) the location of river benthic macroinvertebrate stations, underlain by circumpolar ecoregions; (b) ecoregions with many river benthic macroinvertebrate stations, colored on the basis of alpha diversity rarefied to 100 stations; (c) all ecoregions with river benthic macroinvertebrate 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 67 - Figure 4-30

Circumpolar permafrost extent overlain on ecoregions used in SAFBR analysis, indicating continuous (90-100%), discontinuous (50-90%), sporadic (10-50%), and isolated (0-10%) permafrost extent. Source for permafrost layer: Brown et al. (2002). State of the Arctic Freshwater Biodiversity Report - Chapter 5 - Page 89 - Figure 5-6

Fish species observations from Traditional Knowledge (TK ) literature, plotted in the approximate geographic location of observed record, with symbol colour indicating the number of fish species recorded and shape indicating the approximate time period of observation. Results are from a systematic literature search of TK sources from Alaska, Canada, Greenland, Fennoscandia, and Russia. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 75- Figure 4-37

Figure 4 -36 Freshwater fish sampling stations (A), ecoregion alpha diversity in each of the sampled ecoregions, as quantified by estimates of species richness from reference texts (Muus and Dahlstrøm 1971, Scott and Crossman 1973, Mecklenburg et al. 2002) and expert knowledge (academic and government scientists and traditional knowledge) (B), and ecoregion beta diversity (C) characterized according to components of beta diversity as either nestedness, turnover, no diversity (none, beta = 0), or similar nestedness and turnover (nestedness ~ turnover) in the circumpolar Arctic. Ecoregions are shown only where sampling stations occur. Fish sampling stations included in this study assessed complete fish assemblages at each location. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 74 - Figure 4-36