This striking sea duck has a thin red bill and a scaled dark pattern on the flanks and rump.

Both sexes have a crest of wispy elongated feathers, reaching almost to the shoulders in adult males and being fairly short in females and immatures.

[4] This shy and easily startled bird favors mid-sized rivers which meander through wide expanses of mixed forest in the mountains, up to 1,000 meters ASL or less.

Birds tend to move upriver during the day, both when startled and when foraging; the latter is probably because stirred-up sediments will alert and hide prey downstream.

More rarely eaten are such species as the lamprey Eudontomyzon morii, the sculpin Mesocottus haitej, or the Arctic grayling (Thymallus arcticus).

Current threats include illegal hunting, entanglement in (ghost) fishing nets and river pollution, as well as ongoing destruction of forest.

According to its current IUCN classification EN C2a(ii), fewer than 5000 adult and first and second year old birds remain, and most of these are found in Primorye and South Khabarovsk regions of Russia (85%)[4] World population survey was completed in 2014 both in Russia and China, the number for North Korea was estimated without survey there.

Threats include sand mining, fishing, riparian vegetation destruction, habitat fragmentation, and water pollution.