>> They're friendly, pink and beloved by the people of Hong Kong. But experts say the Chinese White Dolphin faces it's latest battle for survival with a $19 billion project to link the city to mainland China. The dolphins' numbers have fallen nearly 80% over the past decade, and now, there are only 47 of them left in these waters.
>> I'm Reuter's reporter, where sightings of the Chinese White Dolphin have become increasingly rare. And that's largely because of manmade factors, including pollution, boat traffic and development like this, the world's longest running sea crossing bridge. Conservationists say the construction of mega projects like it have had a huge impact on their habitat.
>> The dolphin also known as the Indo Pacific humpback dolphin appears pink because of blood vessels beneath its skin. It was the official mascot of Hong Kong's handover from to China in 1997.>> We've stopped here because we've spotted a handful of dolphins. Now this is a popular feeding spot but there's concern about how healthy one of them is, ie., how fat they are and how they are able to fight off disease.
>> That may be because of noise pollution below the water's surface. According to experts, the noise from construction makes it hard for the animals to feed and even communicate with each other.>> When the Hong Kong to Macau bridge is starting to built, we hear an increase in underwater noise, background noise.
Which is not good for dolphin because they rely on sound to navigate and to find prey.>> The dolphins have been showing other signs of distress like skin lesions and infections due to stress and high noise levels. The government says it plans to designate more marine parks for the animals.
But conservationists warn previous government efforts to compensate for infrastructure projects haven't been successful. And so far, they haven't brought back the dolphins.