Photo shows a school of naked carp swimming upstream along a freshwater river flowing into Qinghai Lake in central China’s Qinghai Province. (Photo/Zhou Yuanfeng)

Huangyu, or the naked carp, is a species of fish endemic to Qinghai Lake, China’s largest inland saltwater lake situated on the Qinghai-Tibet Plateau. The naked carp is also a core species within the water-fish-bird-grass ecosystem of Qinghai Lake. In 2004, the fish was listed on the China Species Red List as an endangered species.

From late May to August every year, the carp swim upstream along freshwater rivers in order to spawn. The journey is an arduous and dangerous one for the fish because there are predators on the way, not to mention unpredictable weather conditions and the fact that the river might stop flowing at some sections.

Thanks to many years of conservation efforts, the naked carp inhabiting Qinghai Lake now add up to an estimated 108,500 tonnes, which is nearly 42 times the total weight determined at the beginning of efforts to protect the species.