The Weddell Sea polynya is an area of open water that sometimes appears in the Weddell Sea over a relatively shallow region called Maud Rise.
In the latest satellite imagery from the DMSP satellite you can see the lower concentration sea ice as the darker blue colour. If you look at the MODIS imagery for the same date you can clear see black which indicates open water in the pack ice.
Sea ice is still relatively low in both the the Arctic spring and Antarctic autumn. A geographical perspective always helps so here is the status of the sea ice concentration 23 April 2017 for both polar regions.
Here is the sea ice concentration 23 April 2017 compared with the 1989-1993 mean on the 23 April. Red shades = less sea ice than the 1989-93 mean on 23 April, and Blue shades = more sea ice than the 1989-93 mean on 23 April.
The stand out regions for me are once more (as in my post in January), the Northern Barents Sea is relatively low, along with the Bering Sea and the Sea of Okhotsk. There is a consistent retreat of the ice edge almost everywhere, and comparatively a lot of open water in Hudson Bay.