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

Spatial distribution of hillslope thermokarst across the circumpolar area, overlain with ecoregions used in the SAFBR analysis, showing no, low, moderate, and high thermokarst. Source for thermokarst layer: Olefeldt et al. (2016) State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 90 - Figure 5-7

Results of circumpolar assessment of lake zooplankton, focused just on crustaceans, and indicating (a) the location of crustacean zooplankton stations, underlain by circumpolar ecoregions; (b) ecoregions with many crustacean zooplankton stations, colored on the basis of alpha diversity rarefied to 25 stations; (c) all ecoregions with crustacean 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 58 - Figure 4-25

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

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

Arthropods (e.g., shrimps, crabs, sea spiders, amphipods, isopods) dominate taxon numbers in all Arctic regions, followed by polychaetes (e.g., bristle worms) and mollusks (e.g., gastropods, bivalves). Other taxon groups are diverse in some regions, such as bryozoans in the Kara Sea, cnidarians in the Atlantic Arctic, and foraminiferans in the Arctic deep-sea basins. This pattern is biased, however, by the meiofauna inclusion for the Arctic Basin (macro- and meiofauna size ranges overlap substantially in deep-sea fauna, so nematodes and foraminiferans are included) and the influence of a lack of specialists for some difficult taxonomic groups. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/benthos" target="_blank">Chapter 3</a> - Page 89 - Box figure 3.3.1 Each region of the Pan Arctic has been sampled with a set of different sampling gears, including grab, sledge and trawl, while other areas has only been sampled with grab. Here is the complete species/taxa number and the % distribution of species/taxa in main phyla, per region of the Pan Arctic.