MANY dead fish were seen in a wetland park where the Pingshan River flows, and local authorities said that the low content of dissolved oxygen in the river was the main cause of deaths, the Shenzhen Special Zone Daily reported Monday.

    According to the environmental protection and water affair bureau in Pingshan District, law enforcers from several government departments headed to the park after receiving reports about dead fish from residents.

    They cleared the dead fish from the river and inspected 25 industrial enterprises nearby, but none of them were involved in illegal disposal of untreated sewage.

    Inspectors also collected water samples from the river, and the lab tests showed that the content of dissolved oxygen in the water was 4mg/L, which is lower than normal.

    According to the report, the number of fish living in Pingshan River has been multiplying rapidly since the river’s water quality was improved in recent years. Also, the rainfall in the area dropped by 20 percent in the first quarter of this year compared with the same period last year.

    The bureau said that the preliminary analysis suggested that lots of the fish had died from oxygen deficiency due to the growing number of fish and the decreased flow of water in the river.

    The bureau promised that it would clear the river as soon as possible, monitor the river’s water quality and crack down on illegal practices that pose a threat to the environment.

    (Zhang Yang)