As reported by several news outlets this week, a Chinese White Dolphin (Sousa chinensis) – aluas Indopacific Humpback Dolphin or ‘pink dolphin’ – was spotted near Guangzhou in the Pearl River on Wednesday the 21st of October. This drew some crowds as the dolphin stayed for about an hour. Conservation staff later used sonar equipment to try to herd it back out towards the sea -apparently with some success.
This story is however quite hyped-up, because these dolphins live near estuaries and previous studies have shown they move further into the estuary in the dry winter months when less freshwater is flushed into the sea by the Pearl River. In summer when the heavy rains come and the river swells the dolphins range extends further out. This is likely because they are following fish stocks that themselves track a line of salinity which mobmves in and out of the estuary with the seasons. Some fish like the flathead mullet (Mugil cephalus) commonly sold in fish markets also move in and out of fresh and seawater depending on their stage in life.
Speaking of which, I saw another prize catch of a mullet on the central waterfront yesterday. It’s a bigger fish than I have seen in any market at about 40 cm and probably 2+ kg – it drew a small crowd and plenty of mobile phone cameras. congratulations to the lucky angler!