Surf scoters breed in Northern Canada and Alaska and winter along the Pacific and Atlantic coasts of North America.

In 1750 the English naturalist George Edwards included an illustration and a description of the surf scoter in the third volume of his A Natural History of Uncommon Birds.

Edwards based his hand-coloured etching on a preserved specimen that had been brought to London from the Hudson Bay area of Canada by James Isham.

[2] When in 1758 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he placed the surf scoter with the ducks and geese in the genus Anas.

The only extinct Melanitta species, M. cerutti, used to be present in California during the late Pliocene, but it has been moved in the genus Histrionicus (Harlequin duck).

The bill is black with green or blue colorations The juvenile has a plumage similar to the female, but mainly paler and browner, and the breast and belly are whitish.

[11] When alarmed, surf scoters will often make a sound like a "guk," somewhere between a "cluck" and a "tok," while rapidly surveying their environment or taking to flight en masse.

The Pacific coast host the highest number of individuals and its large wintering range extends over 5000 km, from the Aleutian Islands in Alaska to the Baja Peninsula in Mexico.

Because of the vulnerable state of the ducks in those periods, molting sites are assumed to have profitable food and lower predation risks and they are located in bays, inlets or estuaries.

This suggest that because of different factors such as the weather or varied foraging conditions, the individuals adjust their migration timing to meet an optimized reproductive schedule.

[19] The building of the nest usually starts in mid-May to early June and it occurs on the ground close to the sea, lakes or rivers, in woodland or tundra.

[13] Occasional (and likely accidental) brood mixing between different females occurs in areas with high densities of nests and hatching is synchronous among the eggs.

During the breeding period, surf scoters forage in pairs or small groups on a diverse range of freshwater invertebrates.

However, the sea ducks feed on marine organisms for the rest of the year, in flocks ranging from a few individuals to several thousands birds.

[13][11] In late winter and spring, Surf scoters tend to shift their diet according to the relative profitability of the food, showing a level of opportunism.

[20] For example, they start feeding in seagrass beds, on epifaunal crustaceans that have increased in size over winter[21] or on Pacific herring eggs (Clupea pallasi), during the fish spawning.

[21][24] Flocks of surf scoter appear to dive in a highly synchronous fashion and this synchrony is correlated with the group size.

[20] Surf scoters increase their dive duration when they are feeding on herring spawning, which are harder to capture than sessile bivalves.

The only parasite found in dead surf scoters was the Acanthocephalan Polymorphus spp., which causes peritonitis, an inflammation of the abdomen's lining, and possibly emaciation.

Scientists said that while the species is not endangered it has declined 50 to 70% over the past 40 years and this spill could decrease populations since most of the affected birds are healthy adults.