Sea ice meiofauna composition (pie charts) and total abundance (red circles) across the Arctic, compiled by the CBMP Sea Ice Biota Expert Network from 27 studies between 1979 and 2015. Scaled circles show total abundance per individual ice core while pie charts show average relative contribution by taxon per Arctic Marine Area (AMA). Number of ice cores for each AMA is given in parenthesis after region name. Note that studies were conducted at different times of the year, with the majority between March and August (see 3.1 Appendix). The category ‘other’ includes young stages of bristle worms (Polychaeta), mussel shrimps (Ostracoda), forams (Foraminifera), hydroid polyps (Cnidaria), comb jellies (Ctenophora), sea butterflies (Pteropoda), marine mites (Acari) and unidentified organisms. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/sea-ice-biota" target="_blank">Chapter 3</a> - Page 40 - Figure 3.1.4 From the report draft: "Here, we synthesized 19 studies across the Arctic conducted between 1979 and 2015, including unpublished sources (B. Bluhm, R. Gradinger, UiT – The Arctic University of Norway; H. Hop, Norwegian Polar Institute; K. Iken, University of Alaska Fairbanks). These studies sampled landfast sea ice and offshore pack ice, both first- and multiyear ice (Appendix 3.1). Meiofauna abundances reported in individual data sources were converted to individuals m-2 of sea ice assuming that ice density was 95% of that in melted ice. Due to the low taxonomic resolution in the reviewed studies, ice meiofauna were grouped into: Copepoda, nauplii (for copepods as well as other taxa with naupliar stages), Nematoda, Polychaeta (mostly juveniles, but also trochophores), flatworms (Acoelomorpha and Platyhelminthes; these phyla have mostly been reported as one category), Rotifera, and others (which include meroplanktonic larvae other than Polychaeta, Ostracoda, Foraminifera, Cnidaria, Ctenophora, Pteropoda, Acari, and unidentified organisms). Percentage of total abundance for each group was calculated for each ice core, and these percentages were used for regional averages. Maximum available ice core length was used in data analysis, but 50% of these ice cores included only the bottom 10 cm of the ice, 12% the bottom 5 cm, 10% the bottom 2 cm, and 11% the entire ice-thickness. Data from 617 cores were used."

Multi-decadal time series of A) abundance (individuals m-2) and B) biomass (g wet weight m-2) of ice amphipods from 1977 to 2012 across the Arctic. Bars and error bars indicate median and median absolute deviation (MAD) values for each year, respectively. Numbers above bars represent number of sampling efforts (n). Modified from Hop et al. (2013). STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/sea-ice-biota" target="_blank">Chapter 3</a> - Page 45 - Figure 3.1.7 From the report draft: "The only available time-series of sympagic biota is based on composite data of ice-amphipod abundance and biomass estimates from the 1980s to present across the Arctic, with most observations from the Svalbard and Fram Strait region (Hop et al. 2013). Samples were obtained by SCUBA divers who collected amphipods quantitatively with electrical suction pumps under the sea ice (Lønne & Gulliksen 1991a, b, Hop & Pavlova 2008)."

Status of monitoring activities for each Focal Ecosystem Component (i.e., selected species groups) across each Arctic Marine Area as included in this report. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/monitoring-status-and-advice" target="_blank">Key Findings</a> - Page 5 - Figure 1

Trends in abundance of marine mammal Focal Ecosystem Components across each Arctic Marine Area. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - Chapter 4 - Page 182 - Figure 4.6

Changes expected or underway in the of energy flow in the High Arctic marine environment STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/marine" target="_blank">Chapter 2</a> - Page 23 - Figure 2.2b

Status of marine mammal Focal Ecosystem Component stocks by Arctic Marine Area. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/marine-mammals" target="_blank">Chapter 3</a> - Page 157 - Figure 3.6.3

Bathymetric features, warm currents (red arrows), cold currents (blue arrows) and riverine inflow in the Arctic. Adapted from Jakobsen et al. (2012). Simplified Arctic Ocean currents (Fig. 2.1) show that the main circulation patterns follow the continental shelf breaks and margins of the basins in the Arctic Ocean. Different global models predict different types of changes, which can cause changes to Arctic ecosystems (AMAP 2013, Meltofte 2013). STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/marine" target="_blank">Chapter 2</a> - Page 22 - Figure 2.1

Arctic Ecologically and Biologically Significant Areas (EBSAs) and Arctic Marine Areas of Heightened Ecological and Cultural Significance as identified in the Arctic Marine Shipping Assessment (AMSA) IIC report. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/marine" target="_blank">Chapter 1</a> - Page 16 - Box Figure 1.1

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."

Bacteria and Archaea across five Arctic Marine Areas based on number of operational taxonomic units (OTUs), or molecular species. Composition of microbial groups, with respective numbers of OTUs (pie charts) and number of OTUs at sampling locations (red dots). Data aggregated by the CBMP Sea Ice Biota Expert Network. Data source: National Center for Biotechnology Information’s (NCBI 2017) Nucleotide and PubMed databases. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/sea-ice-biota" target="_blank">Chapter 3</a> - Page 38 - Figure 3.1.2 From the report draft: "Synthesis of available data was performed by using searches conducted in the National Center for Biotechnology Information’s “Nucleotide” (http://www.ncbi.nlm.nih.gov/guide/data-software/) and “PubMed” (http://www.ncbi.nlm.nih.gov/pubmed) databases. Aligned DNA sequences were downloaded and clustered into OTUs by maximum likelihood phylogenetic placement."