As weather gets warmer, large schools of carps are forming 'traffic jams' in their passage to freshwater in northwest China's Qinghai Province. Locals described the phenomenon as "the rivers are half water, half fish". 

Each year male naked carps over three years old and females over four years old will migrate to freshwater for reproduction between May to August. The migration this year began in late May.

Naked carps are a type of endangered carps mainly found in northwest China's Qinghai Province, and local authorities have made efforts to facilitate their migration and protect the species. For instance, on the Shaliu River, a main passage for naked carps, a dam was modified into stairs to allow the carps to swim through. 

Yet the upstream swim remains a difficult and even deadly journey for naked carps. Naked carps will travel in schools to freshwater entries. They will gather strength together in slow running streams before making the upstream climb. A large portion of the carps will perish in the process, either because they ran out of strength before swimming through, or because they became the feast of the gathering predatory species such as gulls or geese. 

A naked carp will lay 3,000 to 4,000 eggs once it gets to fresh waters suitable for reproduction, of which only less than one percent will survive. 

Conservation efforts

To protect the species, checkpoints have been set up along the Qinghai Lake since May. Strict law enforcement has also been carried out against illegal fishing. In 2018, a court made a first instance verdict on the first case about illegal fishing of the carp. The suspect surnamed Wang was sentenced to five months in prison and confiscated 237.5 kilograms of the fish. 

The local authority has also signed agreements with all restaurants in the region, to prohibit cooking and selling of the carp and other wild fishes during the spawning period. 

"We do not cook or sell the Qinghai Lake naked carp because it is a protected species," said Tao Sulan, a local restaurant owner. 

The tents have been set up in key areas to ensure smooth spawning period of the species.

"We will patrol the rivers every two or three days to ensure smooth water flow of the main waterway on the one hand, and on the other, to close gates to irrigation areas in case the carp flush into the areas and gets stranded," said Ragya Tsering, a law enforcement official of the local fisheries law enforcement administration. 

As of the end of 2018, the standing stock of the Qinghai Lake naked carp had reached 88,000 tonnes, 6,800 tonnes more than that of last year and about 34 times more than the 2,600 tonnes in 2002. 

(Top image via VCG)

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