"None of the Chinese white dolphins under the State's strict protection has been found dead while construction of the bridge was going on," he added.

The Y-shaped bridge, which will take more than 105 billion yuan ($16 billion) to build, is expected to start carrying traffic in early 2018 and will cut the land travel time between Hong Kong and Zhuhai from 3 hours to just 30 minutes. It is part of the country's planned national highway network, connecting the western and eastern parts of Pearl River and further integrating the cities in the Pearl River Delta.

On Monday night, a lighting ceremony for the exit-entry checkpoint for the HZM Bridge was held in Macao, indicating it is ready to go into service.

The exit-entry facility, covering 658,000 square meters, is a key project for the bridge and the first to be completed in the three regions.