[2] Onset of magmatic sea-floor spreading was accompanied by volcanic eruptions of picrites and basalts in the Paleocene at the Davis Strait and Baffin Bay.

Natural Resources Canada uses a slightly different definition, putting the northern boundary of the Labrador Sea on a straight line from a headland on Killiniq Island abutting Lady Job Harbour to Cape Farewell.

It becomes shallower, to less than 700 m (383 fathoms; 2,297 ft) towards Baffin Bay (see depth map) and passes into the 300 km (190 mi; 160 nmi) wide Davis Strait.

[9][10] It is called the Northwest Atlantic Mid-Ocean Channel (NAMOC) and is one of the world's longest drainage systems of Pleistocene age.

[11] It appears as a submarine river bed with numerous tributaries and is maintained by high-density turbidity currents flowing within the levees.

This drift ice serves as a breeding ground for several types of pinnipeds (including Atlantic walrus and bearded, grey, harbor, harp, hooded and ringed seals).

Several cetacean species feed in these abundant waters in early spring, including blue, fin, humpback, long-finned pilot, minke, North Atlantic right, sei and sperm whales.

[22] Additionally, pods of orca are drawn to the sea by the large shoals of fish, as well as the many marine mammal species they may hunt (including other cetaceans and pinnipeds), such as harbour porpoise and Atlantic white-sided, common, striped and white-beaked dolphins.

[13] Other fishery targets include haddock, Atlantic herring, lobster, several species of flatfish, and pelagic fish, such as sand lance and capelin.

[24] Other coastal animals include the Labrador wolf (Canis lupus labradorius),[25][26] woodland caribou (Rangifer tarandus caribou), moose (Alces alces), black bear (Ursus americanus), Canada lynx (Lynx canadensis), red fox (Vulpes vulpes), Arctic fox (Alopex lagopus), wolverine (G. gulo), American mink (Neogale vison), North American river otter (Lontra canadensis), snowshoe hare (Lepus americanus), grouse (Dendragapus spp.

[27][28] Occasionally, coastal polar bear (Ursus maritimus) sightings occur along the sea, mainly further north but sometimes as far south as Conception Bay and the mouth of the Gulf of Saint Lawrence.