Sea · Canada
Hudson Bay
Hudson Bay is a huge but shallow bay in north-eastern Canada, joined to the Atlantic by Hudson Strait. Every winter it freezes over, and polar bears walk out onto the ice to hunt seals.
Picture credit: Josh Campbell (CC BY 2.0) · Gerald Ludwig, U.S. Fish and Wildlife Service (Public domain) · Wikimedia Commons
Where is Hudson Bay?
Part of: Arctic Ocean.
Countries on its coasts: Canada.
The story behind it
Hudson Bay is named after the explorer Henry Hudson, who began exploring it in 1610. Counting its side waters – Hudson Strait, James Bay, Ungava Bay and Foxe Basin – it covers about 1.23 million km²; the main bay alone covers about 820 000 km². For such a big bay it is shallow: only about 100 to 130 metres deep on average. From the middle of December to the middle of June it is frozen. Polar bears need this ice, because only from the frozen bay can they reach the seals they eat. As the ice melts earlier and earlier because of global warming, life is getting harder for them. Many polar bears gather around the town of Churchill. About 54 000 beluga whales live in the western part of the bay. Many rivers bring in fresh water, so the bay is less salty than the ocean. Villages such as Arviat, Rankin Inlet and Inukjuak lie on its shores.
Find it on the globe
Hudson Bay is there as a name written across its water — tap the water and its card opens. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
Questions children ask
How big is Hudson Bay?
Together with Hudson Strait, James Bay, Ungava Bay and Foxe Basin, Hudson Bay covers about 1.23 million km². The main bay on its own covers about 820 000 km².
Why do polar bears need the ice on Hudson Bay?
Polar bears mainly eat seals, and they can only reach them from the frozen bay. The bay is frozen from the middle of December to the middle of June.
Is Hudson Bay part of the Arctic Ocean or the Atlantic?
The International Hydrographic Organization counts Hudson Bay as part of the Arctic Ocean. Some experts count it as part of the Atlantic, because Hudson Strait links it to the Labrador Sea.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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