From UPSC perspective, the following things are important :
Prelims level : IUCN , Red List, Chinese paddlefish
Mains level : IUCN mechanism of listing
One of the largest freshwater species, Chinese paddlefish has been declared extinct.
- The Chinese paddlefish (Psephurus gladius) was an iconic species, measuring up to 7 m in length, dating back from 200 million years ago, and therefore swimming the rivers when dinosaurs ruled the Earth.
- Its ancestral home was the Yangtze River.
- It was once common in the Yangtze, before overfishing and habitat fragmentation — including dam building — caused its population to dwindle from the 1970s onwards.
- Between 1981 and 2003, there were just around 210 sightings of the fish. The researchers estimate that it became functionally extinct by 1993, and extinct sometime between 2005-2010.
How did the study determine that it has gone extinct?
- Chinese researchers made this conclusion based on the Red List criteria of the International Union for Conservation of Nature (IUCN).
- The Red List has several categories for extinction, or for how endangered a species is.
- For example, “extinct in the wild” means a species survives only in a captive environment while “locally extinct” means a species has ceased to exist in a particular area but may exist in other areas.
- Then there is “functionally extinct”, which means the species continues to exist but it has too few members to enable to reproduce meaningfully enough to ensure survival.
- To be “globally extinct”, it means a species has no surviving member anywhere. Such a conclusion is reached when there is no reasonable doubt left that its last member has died.
How does extinction status matters for conservation?
- Declaring a species extinct is an elaborate process.
- It involves a series of exhaustive surveys, which need to be taken at appropriate times, throughout the species’ historic range and over a time-frame that is appropriate to the species’ life cycle and form.
- When these surveys fail to record the existence of any individuals belonging to that species, a species may be presumed to be extinct.
- Once declared extinct, a species is not eligible for protective measures and conservation funding; therefore, the declaration has significant consequences.