Some features of the sea ice environment. Marine areas seasonally or permanently covered by sea ice are a globally unique habitat. Ice edges and open water areas favour wind-driven mixing of the seawater that enhances local production and can create biological hotspots. Adapted from Eamer et al. (2013). STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/marine" target="_blank">Chapter 2</a> - Page 20 - Box Fig 2.1

Boundaries of the 22 ecoregions (grey lines) as defined in the CSMP (Irons et al. 2015) and the Arctic Marine Areas (colored polygons with names in legend). Filled circles show locations of seabird colony sites recommended for monitoring (‘key sites’). The current level of monitoring plan implementation are green = fully implemented, amber = partially implemented, red = not implemented. The CSMP provides implementation maps for each forage guild. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/seabirds" target="_blank">Chapter 3</a> - Page 132 - Figure 3.5.1 This graphic displays the status of seabird monitoring at key sites in CBMP areas across the Arctic.

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

Commercial fishery impact on zoobenthos of the Barents Sea. Figure A) Intensity and duration of fishery efforts in standard commercial fishery areas in the Barents Sea. The darker the area the longer the fishery has been in operation. Figure B) Level of decline in macrobenthic biomass between 1926-1932 and 1968-1970 calculated as 1-b1968/b1930. The largest biomass decreases correspond to the darker colour, whereas lighter colour refers to no change (Denisenko 2013). STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/benthos" target="_blank">Chapter 3</a> - Page 97 - Figure 3.3.4

Sea ice provides a wide range of microhabitats for diverse biota including microbes, single-celled eukaryotes (labelled algae), multicellular meiofauna, larger under-ice fauna (represented by amphipods), as well as polar cod (Boreogadus saida). Modified from Bluhm et al. (2017). STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/sea-ice-biota" target="_blank">Chapter 3</a> - Page 35 - Figure 3.1.1

Number of megafauna species/taxa in the Arctic (7,322 stations in total), based on recent trawl investigations. Stations with highest species/taxon number are sorted to the top, meaning that dense concentrations of stations (e.g. Eastern Canada, Barents Sea), with low species numbers are hidden behind stations with higher species numbers. Also note that species numbers are somewhat biased by differing taxonomic resolution between studies. Data from: Icelandic Institute of Natural History, Iceland; Marine Research Institute, Iceland; University of Alaska, Fairbanks, U.S.; Greenland Institute of Natural Resources, Greenland; Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; Université du Québec à Rimouski, Canada; Fisheries and Oceans Canada; Institute of Marine Research, Norway; and Polar Research Institute of Marine Fisheries and Oceanography, Murmansk, Russia. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/benthos" target="_blank">Chapter 3</a> - Page 91 - Box figure 3.3.2 Several regions of the Pan Arctic have been sampled with trawl. Even though the trawl configurations and the taxonomic level are different from area to area, we choose to consider the taxonomic richness as relatively comparative.

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.

Distribution of Greenland halibut (Reinhardtius hippoglossoides) based on participation in research sampling, examination of museum voucher collections, literature and molecular genetic analysis (Mecklenburg et al. 2011, 2014, 2016, Mecklenburg and Steinke 2015). Map shows the maximum distribution observed from point data and includes both common and rare locations. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/marine-fishes" target="_blank">Chapter 3</a> - Page 120 - Figure 3.4.7

Seasonal time series of the major zooplankton in Franklin Bay, Canada STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/plankton" target="_blank">Chapter 3</a> - Page 78 - Figure 3.2.9 Mesozooplankton abundance, integrated from 10 m above the seafloor to the surface (ind m-2), in Franklin Bay during the CASES 2003-04 overwintering expedition. Most of the sampling was done at the overwintering station and a few stations were close to this site in autumn 2003 and summer 2004.

Numbers and taxonomic composition of five single-celled eukaryote groups for the regional divisions of the Arctic Marine Areas (pie charts), as well as the number of data sources reviewed across the Arctic (red circles). Total number of taxa is given in parenthesis after each region. Flagellates include: chlorophytes, chrysophytes, cryptophytes, dictyochophytes, euglenids, prasinophytes, prymnesiophytes, raphidophytes, synurales, and xanthophytes, and- for practical purposes though not flagellates - cyanophytes. Heterotrophs include: choanoflagellates, kinetoplastea, incertae sedis. Updated from Poulin et al. (2011). STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/sea-ice-biota" target="_blank">Chapter 3</a> - Page 39- Figure 3.1.3 From the report draft: "For a pan-Arctic assessment of diversity (here defined as species richness), the first comprehensive assessments of this FEC from a few years ago (Poulin et al. 2011, Daniëls et al. 2013) have been updated for regions, with taxonomic names standardized according to the World Register of Marine Species (www.marinespecies.org). For the analysis of possible interannual trends in the ice algal community, we used a data set from the Central Arctic, the area most consistently and frequently sampled (Melnikov 2002, I. Melnikov, Shirshov Institute, unpubl. data). Multivariate community structure was analysed based on a presence-absence matrix of cores from 1980 to 2013. The analysis is biased by the varying numbers of analysed cores taken per year ranging widely from 1 to 24, ice thickness between 0.6 and 4.2 m, and including both first-year as well as multiyear sea ice. Locations included were in a bounding box within 74.9 to 90.0 °N and 179.9°W to 176.6°E and varied among years."