On December 12, 2006, biologists declared the baiji (Chinese river dolphin) "functionally extinct." The international authority on endangered species (the IUCN) classifies the baiji as “critically endangered,” although there have been no confirmed baiji sightings in recent years.
Baiji were freshwater dolphins, one of only four known species. They were indigenous to China's Yangtze River. Their numbers fell from more than 6,000 in the 1950s to about 400 by 1984. Factors contributing to their extinction include fishing, dams, and industrial pollution.
Term Part of Speech Definition Encyclopedic Entry biologist Noun
scientist who studies living organisms.
structure built across a river or other waterway to control the flow of water.
endangered species Noun
organism threatened with extinction.
Encyclopedic Entry: endangered species extinct Adjective
no longer existing.
element contributing to an event or outcome.
to catch or harvest fish.
having to do with a habitat or ecosystem of a lake, river, or spring.
characteristic to or of a specific place.
having to do with factories or mechanical production.
International Union for the Conservation of Nature (IUCN) Noun
environmental organization concerned with preserving natural ecosystems and habitats.
introduction of harmful materials into the environment.
Encyclopedic Entry: pollution