In 2017 the SAMBR synthesized data about biodiversity in Arctic marine ecosystems around the circumpolar Arctic.. SAMBR highlighted observed changes and relevant monitoring gaps. This 2021 update provides information on the status of marine mammals in the Arctic from 2015–2020: More detail can be found in the Marine Mammals 2021 Technical report. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT

Figure 3.2.2a: Relative abundance of major eukaryote taxonomic groups found by high throughput sequencing of the small-subunit (18S) rRNA gene across Arctic Marine Areas. Figure 3.2.2b: Relative abundance of major eukaryote functional groups found by microscopy in the Arctic Marine Areas. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/plankton" target="_blank">Chapter 3</a> - Page 70 - Figures 3.2.2a and 3.2.2b

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.

In 2017, the SAMBR synthesized data about biodiversity in Arctic marine ecosystems around the circumpolar Arctic. SAMBR highlighted observed changes and relevant monitoring gaps using data compiled through 2015. In 2021 an update was provided on the status of seabirds in circumpolar Arctic using data from 2016–2019. Most changes reflect access to improved population estimates, orimproved data for monitoring trends,independent of recognized trends in population size.

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

Summary of the taxa accounting for 85% of the river 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) western Canada, (3) southern Canada, south of Hudson Bay, (4) northern Labrador, (5) Baffin Island, (6) Ellesmere Island, (7) Greenland high Arctic, (8) Greenland low Arctic, (9) Iceland, (10) Svalbard, and (11) Fennoscandia. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 70 - Figure 4-34

Number of non-native plant taxa that have become naturalised across the Arctic. No naturalised non-native taxa are recorded from Wrangel Island, Ellesmere Land – northern Greenland, Anabar-Olenyok and Frans Josef Land. Modified from Wasowicz et al. 2020 STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 32 - Figure 3.4

Trends in abundance or diversity of sea ice biota Focal Ecosystem Components across each Arctic Marine Area. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - Chapter 4 - Page 177 - Figure 4.1

Figure 4-7 Circumpolar assessment of lake diatoms, indicating (a) the location of lake diatom stations, underlain by circumpolar ecoregions; (b) ecoregions with many lake diatom stations, colored on the basis of alpha diversity rarefied to 40 stations; (c) all ecoregions with lake diatom 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 (i.e. species turnover, nestedness, approximately equal contribution, or no diversity) when averaged across hydrobasins in each ecoregio. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 35 - Figure 4-7

Trends in abundance of plankton Focal Ecosystem Components across each Arctic Marine Area. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - Chapter 4 - Page 178 - Figure 4.2