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)."

Circumpolar map of known polynyas. Note that polynyas are dynamic systems and some may no longer exist in the form known from their recent history. Adapted from Meltofte (2013) and based on Barber and Massom (2007). STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/marine" target="_blank">Chapter 2</a> - Page 28 - Figure 2.5

Estimated consumption of polar cod by Atlantic cod in the Barents Sea (yellow line) and biomass of the Atlantic cod stock in the Barents Sea (red line) (ICES 2016). The blue line is the biomass of the Barents Sea polar cod (Prozorkevich 2016). STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/marine-fishes" target="_blank">Chapter 3</a> - Page 116 - Box figure 3.4.1

Arctic Marine Areas (AMAs) as defined in the CBMP Marine Plan. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/marine" target="_blank">Chapter 1</a> - Page 15 - Figure 1.2

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.

Relative abundance of major eukaryote taxonomic groups found by high throughput sequencing of the small-subunit (18S) rRNA gene. Time series collected by sampling every 2-6 weeks in Amundsen Gulf of the Beaufort Sea over the winter-spring transition in 2007–2008. Sampling DNA gives information about presence/absence, while sampling RNA gives information about the state of activity of different taxa. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/plankton" target="_blank">Chapter 3</a> - Page 72 - Figures 3.2.3

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."

Megafauna distribution of biomass (g/15 min trawling) in the Barents Sea in 2007, 2011 and 2015. The green circles show the distribution of the snow crab as it spreads from east to west, and the blue triangles show the invasion of king crab along the coast of the southern Barents Sea. Data from Institute of Marine Research, Norway and the 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 95 - Figure 3.3.2 The annual joint Norwegian–Russian Ecosystem Survey provides from more than 400 stations and during extensive cruise tracks covering more or less the whole Barents Sea in August– September. The sampling is based on a regular grid spanning about 1.5 millionkm2 with fixed positions of stations which make it possible to measure changes in spatial distribution over time. The trawl is a Campelen 1800 bottom trawl rigged with rock-hopper groundgear and towed on double Warps. The mesh size is 80 mm (stretched) in the front and 16–22 mmin the cod end, allowing the capture and retention of smaller fish and the largest benthos from the seabed (benthic megafauna). The horizontal opening was 11.7 m, and the vertical opening 4–5 m (Teigsmark and Øynes, 1982). The trawl configuration and bottom contact was monitored remotely by SCANMAR trawl sensors. The standard distance between trawl stations was 35 nautical miles (65 km), except north and west of Svalbard where a stratified sampling was adapted to the steep continental shelve. The standard procedure was to tow 15 min after the trawl had made contact with the bottom, but the actual tow duration ranged between 5 min and 1 h and data were subsequently standardized to 15 min trawl time. Towing speed was 3 knots, equivalent to a towing distance of 0.75 nautical miles (1.4 km) during a 15 min tow. The trawl catches were recorded using the same procedures on the Russian and the Norwegian Research vessels to ensure comparability across Barents Sea regions. The benthic megafauna was separated from the fish and shrimp catch, washed, and sorted to lowest possible taxonomic level, in most cases to species, on-Board the vessel. Species identification was standardized between the researcher teams by annually exchanging the benthic expert’s among the vessels and taxon names were fixed each year according toWORMSwhen possible.This resulted in an Electronic identification manual and photo-compendium as a tool to standardize taxon identifications, in addition to various sources of identification literature. Difficult taxa were photographed and, in some cases, brought back as preserved voucher specimens for further identification. Wet-weight biomass was recorded with electronic scales in the ship laboratories for each taxon.The biomass determination included all fragments.

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