This dolphin lives along coasts of the Indian and western Pacific oceans and also uses estuaries. Hong Kong has carried out long-term monitoring of the Pearl River Estuary population.
Calves are dark gray; juveniles become grayish pink with spots; and the spots fade as adults become pinkish white.
Indo-Pacific humpback dolphins around Hong Kong form part of a wider population using the Pearl River Estuary. Long-term Hong Kong monitoring estimated about 158 animals in 2003, around 87 in 2010–2011, 65 in 2015–2016 and 32 in 2018. These are estimates from particular survey periods, not a simple annual count made by one unchanged method.
The article discusses acoustic records alongside visual surveys and describes overlapping use areas around Hong Kong and the Pearl River Estuary. Acoustic listening adds a second kind of evidence beside sightings. Individual movement and survey design also affect estimates, so comparisons are clearer when methods and locations are tracked separately over time.
An extinction-risk assessment has not been added yet.
Long-term monitoring around Hong Kong estimated a decline from about 158 dolphins in 2003 to 32 in 2018. Estimates depend on survey area and method, so continued regional monitoring using visual and acoustic evidence can help interpret local patterns within the wider estuary.