also: うみどり
noun
seabird; sea bird
General term for birds that live primarily in marine environments.
この島には多くの海鳥が生息している。
Many seabirds inhabit this island.
海鳥の観察が趣味です。
Seabird watching is my hobby.
Standard kanji form; reading かいちょう is more common in news and formal contexts.
Alternate reading, somewhat less common but still used.
水鳥 refers to waterfowl or aquatic birds in general, including freshwater species, while 海鳥 specifically refers to seabirds.
Compound of 海 (sea) and 鳥 (bird).