Trends in water temperature and salinity (A) and density of phytoplankton of two size ranges (B), Canada Basin, 2004 to 2008. Stratification of the water column increased throughout the Canada Basin over a recent five-year period, accompanied by a change in phytoplankton communities. The upper ocean layer showed trends of increased temperature and decreased salinity (Figure 18A), which combine to make this layer progressively less dense. The layer of water below this did not change in density over this period (not shown). The larger size class of phytoplankton (which would include diatoms) decreased in abundance, while the smaller types of plankton increased (Figure 18B). In addition to the trends shown, nutrient content in the upper ocean water layer decreased. Abundance of microbes (bacteria and similar organisms) that subsist on organic matter increased. Total phytoplankton biomass, however, remained unchanged. If this trend towards smaller species of phytoplankton and microbes is sustained, it may lead to reduced production of zooplankton, an impact that would be transmitted through the food web to birds, fish and mammals. Published in the Life Linked to Ice released in 2013, page 30. Life Linked to Ice: A guide to sea-ice-associated biodiversity in this time of rapid change. CAFF Assessment Series No. 10. Conservation of Arctic Flora and Fauna, Iceland. ISBN: 978-9935-431-25-7.

The Arctic territory is roughly subdivided along two main axes in latitudinal subzones (Fig. 9.1) and longitudinal floristic provinces (Fig. 9.2). The latitudinal northsouth axis mainly reflects the present climate gradient divided into five different subzones, which are separated according to climate and vegetation in the lowlands of each zone. Published in the Arctic Biodiversity Assessment, Chapter 9 - released in 2013

Alpha diversity (rarefied to 10 stations, with error bars indicating standard error) of river benthic macroinvertebrates plotted as a function of the average latitude of stations in each hydrobasin. Hydrobasins are coloured based on country/region State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 68 - Figure 4-32

Orgination of macrophyte data (axis labels should be changed from Dim1 to Axis I and from Dim2 to Axis II), with symbols/colours differing by region. State of the Arctic Freshwater Biodiversity Report - Chapter 3 - Page 55 - Figure 4-24

Average relative abundance of the main zooplankton groups (calanoid copepods, cyclopoid copepods, cladocerans) for the sub-Arctic (n=150), low- Arctic (n=154), and high-Arctic (n=55) regions. Samples with a single taxon have been excluded. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 61 - Figure 4-28

Seasonal abundance (1000 individuals m- 2) of sea ice meiofauna at landfast sea ice (Barrow, 2005-2006, A and C) and pack ice (North of Svalbard, 2015, B and D). A and B show larval stages (polychaete juveniles and nauplii, respectively), while C and D show nematodes and harpacticoid copepods, respectively. Circles represent individual cores (n = 107 for A and C, and 39 for B and D), shading the extent of minimum as well as maximum values, and blue line indicates mean values. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/sea-ice-biota" target="_blank">Chapter 3</a> - Page 43 - Figure 3.1.5 From the report draft: "In addition to showing composition and peak abundance ranges, we illustrate the phenology of ice meiofauna over the ice-covered season in the entire combined data set. For this purpose, the data were normalized to the daylight hours at each location during the date of sampling using R package geosphere (Hijmans 2015) and a method described in Forsythe et al. (1995). This was necessary, because ‘spring’ arrives earlier at lower latitudes than at higher latitudes, so that using month or day of year would obscure the pan-Arctic integration of the data. Other influential factors such as snow depth, ice thickness and nutrient concentrations were not accounted for in this analysis."

Benthic macro-infauna biomass in the northern Bering and Chukchi Seas from 1970 to 2012, displayed as decadal pattern Adapted from Grebmeier et al. (2015a) with permission from Elsevier. STATE OF THE ARCTIC MARINE BIODIVERSITY REPORT - <a href="https://arcticbiodiversity.is/findings/benthos" target="_blank">Chapter 3</a> - Page 98 - Figure 3.3.6 Cumulative scores of benthos drivers for each of the 8 CAFF-AMAs. The cumulative scores are taken from the last column of Table 3.3.1. The flower chart/plot helps to visualize the data.

We present the first digital seafloor geomorphic features map (GSFM) of the global ocean. The GSFM includes 131,192 separate polygons in 29 geomorphic feature categories, used here to assess differences between passive and active continental margins as well as between 8 major ocean regions (the Arctic, Indian, North Atlantic, North Pacific, South Atlantic, South Pacific and the Southern Oceans and the Mediterranean and Black Seas). The GSFM provides quantitative assessments of differences between passive and active margins: continental shelf width of passive margins (88 km) is nearly three times that of active margins (31 km); the average width of active slopes (36 km) is less than the average width of passive margin slopes (46 km); active margin slopes contain an area of 3.4 million km2 where the gradient exceeds 5°, compared with 1.3 million km2 on passive margin slopes; the continental rise covers 27 million km2 adjacent to passive margins and less than 2.3 million km2 adjacent to active margins. Examples of specific applications of the GSFM are presented to show that: 1) larger rift valley segments are generally associated with slow-spreading rates and smaller rift valley segments are associated with fast spreading; 2) polar submarine canyons are twice the average size of non-polar canyons and abyssal polar regions exhibit lower seafloor roughness than non-polar regions, expressed as spatially extensive fan, rise and abyssal plain sediment deposits – all of which are attributed here to the effects of continental glaciations; and 3) recognition of seamounts as a separate category of feature from ridges results in a lower estimate of seamount number compared with estimates of previous workers. Reference: Harris PT, Macmillan-Lawler M, Rupp J, Baker EK Geomorphology of the oceans. Marine Geology.

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