An autopsy has been conducted on an endangered Chinese white dolphin that died last week after it swam up a river in south China's Guangdong Province.

Staff with Hong Kong Ocean Park will report the findings of the autopsy as soon as possible, according to a Guangdong reserve for the dolphins.

The mature dolphin, around 30 years old, swam into the Baisha River, a tributary of the Pearl River in Jiangmen, on Feb. 1.

Wildlife experts attempted to rescue it but its health deteriorated noticeably over the 10 days it spent in the river. It is thought that the dolphin may have been suffering navigation issues due to its age.

Each year, Guangdong reports two to three cases of elderly white dolphins mistakenly entering freshwater rivers.

Chinese white dolphins can be found in just a handful of coastal areas and only in small numbers. There are about 2,000 at the mouth of the Pearl River.