Rare white dolphins were spotted as the world's longest sea bridge was unveiled to the public.
China's massive Hong Kong-Zhuhai-Macau Bridge was officially opened on Tuesday.
Marine life conservationists had opposed the bridge but as soon as it was unveiled, a pod of endangered dolphins were spotted nearby.
The dolphins were pictured swimming with the imposing structure in the background and leaping above the surface of the water.
The 34-mile sea bridge is an extensive length of road, consisting of three cable-stayed bridges, one undersea tunnel, and two artificial islands.
It spans the Lingdingyang channel, connecting Hong Kong with Macau with Zhuhai on mainland China, costing $15 billion and likely to carry 29,000 vehicles per day.
Waters in the Pearl River Estuary are an important habitat for the endangered species, prompting China to prioritise them for protection, during the construction of the bridge, said Chinese media.
The nine-year project had faced a lot of criticism over the impacts on marine life. The reason cited was the construction through the ocean waters would affect the marine life adversely.
Chinese President and communist party leader Xi Jinping announced the opening at a ceremony in Zhuhai Port.
The controversial project will be seen as powerful symbol of renewed connections between mainland china with the semi-autonomous cities.
But it attracted a huge amount of controversy, as Hong Kong's South Chine Morning Post (SCMP) reported 20 workers were killed during its construction, and the dolphin population in the areas has fallen 40 per cent despite efforts to mitigate the impact.
Chan Kam-hong, chief executive of the Association for the Rights of Industrial Accident Victims, said on Tuesday at least nine workers lost their lives on the Hong Kong section due to industrial accidents.
“Some workers died after falling into the sea … It was later revealed that life jackets provided by the contractors were substandard,” he said.
Conservationists also called for a review of Hong Kong’s environmental assessment system, saying mitigation measures had been "ineffective" in protecting the endangered dolphins.
The number of dolphins north of Lantau Island reportedly dropped to almost zero over the last six years, the activist added.
Michael Lau Wai-neng, of Hong Kong's Advisory Council on the Environment, said work was needed to improve 20-year-old environmental regulation, SCMP reported.
