Several major water-supplying rivers of Qinghai
Lake have run dry due to drought and man-made development since
the beginning of July, causing the mass death of a rare carp.
The fish - Gymnocypris
przewalskii - are only found in the region, in their spawning
migration from the lake to its tributaries.
According to Beijing-based China Meteorological Paper,
tens of thousands of parent fish got stranded on the river bed of
the Shaliu River, the second largest spawning ground for the carp,
forming a 5 centimeter-thick "dead-fish tunnel," extending about
200 meters. It is estimated more than 500 tons of Gymnocypris
przewalskii were killed by lack of water.
An expert from the local regulatory fishery body said dams and
irrigation constructions were the main causes of the tragedy.
According to the expert, dams built across the Shaliu, Hairag
and other rivers have cut off the routes used by the fish during
their spawning migration. Obstructed, a lot of fish - approximately
500,000 each year-teem around the foot of the dams and get
stranded, before dying.
To supply water to the nearby 75,000-acre farmland, a large
amount of water is drained from the rivers every year. Moreover,
the cultivation of grassland into farmland near Qinghai Lake and
the rivers since 1960s has, over the years, caused great damage to
the local ecosystem, and aggravated the water shortage by stepping
up the desertification of the area.
Eighty-five percent of the 108 freshwater rivers running into
Qinghai Lake have ceased to flow, and the water level of the lake
has been declining at a yearly speed of 10.7 centimeters.
Excessive fishing also poses a threat to the fish resources.
According to a recent report issued by the regulatory body, the
amount of fish in Qinghai
has been reduced by more than 90 percent, from 18 tons per square
kilometer to 1.74 tons in the same unit area since the 1960s.
The increased mineral content of the water and the chemical
wastes dumped into the lake and rivers have also claimed the lives
of thousands of tons of mature fish, according to the report.
Biologists say the local ecosystem has already suffered from the
destruction of the fish resources, and the extinction of the fish
will lead to the extinction of endangered bird species who rely on
the fish for food.
Measures are being taken to cope with the problem. Passageways
and middle-sized reservoirs are being built to enable the fish to
swim across the dams to reproduce and ensure them enough water
during the dry season.
A large spawning ground has been constructed, where fish fry are
raised artificially.
Fishing in Qinghai Lake and the rivers has been banned from 2001
to 2010.
To protect the local ecosystem in the long run, a program to
reforest the cultivated farmland is well under way.
(China
Daily 08/22/2001)