Canada’s Oceans Now: Arctic Ecosystems 2023 - Sea ice changes

Sea ice changes
Sea ice is changing across the Arctic. These changes influence Arctic marine ecosystems in many ways. Each box shows a different way that the ice is changing.

This infographic is separated into four distinct boxes, labeled A through D. In the center of these boxes, a map of the Canadian Arctic and Greenland shows the areas in which sea ice changes depicted in boxes A through D are occurring. Protected areas are highlighted in orange.

On the top left, Box A highlights how ice duration in the coastal zone is changing. The text states:

• In the Anguniaqvia Niqiqyuam Marine Protected Area, coastal sea ice lasts a full month less than it did 40 years ago.
• Below the text, two diagrams compare open water days 40 years ago (top) to open water days today (bottom). 40 years ago, open water days were from mid-July to mid-October. Today, open water days are from late June to early November, showing an increase of 30 days. The open water days are depicted in blue, the ice cover is indicated by solid white or the white pieces of ice.

On the bottom left, Box B highlights how ice extent in the whole Arctic is changing. Two scatter graphs within this box depict summer ice extent (left) and winter ice extent (right) in terms of ice coverage from 1978 to 2023. The bottom axis is years, the side axis is ice coverage. Summer ice extent has decreased by 42% within that time, with most of the decrease occurring before 2008. Winter ice extent has decreased by 10% at a steady rate within that time.

On the top right, Box C highlights how ice transport in the Fram Strait is changing. The text states:

• Ice moves from the Arctic Ocean into the Atlantic through the Fram Strait. Until 2007, the ice was thick and rugged. Since then, the ice has been thin and much flatter.
• Below the text, two illustrations show the thick and rugged ice before 2007 (top) and the thin and flat ice after 2007 (bottom). Ice/snow at the surface of the ocean is white, ice below the surface is grey and the ocean water is dark blue.

On the bottom right, Box D highlights how ice structures in the Arches are changing. The text states:

• An ice arch is a structure that blocks mobile sea ice. This allows an area with open water (a polynya) to form beside the arch. Polynyas are important open-water habitats in otherwise ice-covered areas. In a polynya, phytoplankton can bloom earlier in spring, fish can gather, and marine mammals and seabirds can find food.

Above the text, a series of four illustrations show how an ice arch forms within solid ice, allows a polynya to form, and then the ice arch eventually collapses. The first illustration shows solid ice as a fully white area between grey land.  The second illustration shows ice arch formation as some ice begins to crack up but ice between two areas of land remains solid. The third illustration shows the solid ice arch between two areas of land, holding back ice behind it. This allows for the blue open water beside the ice arch. This open water surrounded by white ice is the polynya. The fourth illustration shows the ice arche collapsing allowing white chunks of ice to flow into the previously open water of the polynya. Text on the bottom right of the four illustrations states that arches are forming later and collapsing earlier in the year. Comparing data from 1992 to 2020, the Lancaster ice arch lasts on average 1.5 months less and the North Water ice arch lasts on average 3 months less. The latter failed to form for the first time in 2007, and again in 2009, 2010, 2017, and 2019.