Thaindian News

Shanghai, Apr.6 (ANI): Almost 70 percent of fish resources in the Pearl River, China’s third longest river, is under threat due to excessive damming, experts have warned.

Estimates suggest that more than 260 fish species will face extinction in the next five to 10 years due to dams being constructed along the river and its tributaries and if greater efforts are not made to protect the endangered species, they could become extinct like the Yangtze River Dolphin, a 20 million-year-old species nicknamed “the goddess of the Yangtze”.

Li Xinhui, a researcher with the Pearl River Fisheries Research Institute under the Chinese Academy of Fishery Sciences, said construction work has disrupted migration routes taken by some fish species and changed the environment of many spawning places.

Samples collected near the biggest spawning site along the river show that both the number of individual fish and the number of fish species have declined significantly in the past three years, Xinhua quoted Li as saying.

Li also noted that the numbers of many types of common freshwater fish have decreased as result of changes in the aquatic environment.

The four major species of freshwater fish in China, black carp, grass carp, silver carp and crucian carp, have become rare as their spawning rates have fallen, while the numbers of alien species have risen.

Rare and endemic fish, such as Dabry’s sturgeon, a unique species that has been living in the Yangtze River for more than 140 million years, and the Hilsa herring, have also disappeared in recent years from the Pearl river as a result of over-fishing and deteriorating water quality.
In order to maintain the diversity of aquatic species in China, Li suggested that changes should be made in the construction of Dams in the river to allow fish to migrate and spawn. One way of doing this could be the construction of separate channels that fish can take upstream to their spawning sites. (ANI)