BUNBURY beach-goers were stumped by a strange discolouration off the Back Beach this week, but it turns out the rain is to blame for the peculiar sight.
Resident Mary Noble told the Mail it was a "fresh water plume" - the result of high flows caused by recent rainfall in the catchments of the Collie and Preston Rivers feeding the Leschenault Estuary and coming out at the Cut.
This was confirmed by Dolphin Discovery Centre marine biologist Phil Coulthard.
"It's pretty cool to think that the brown water we see there was probably at Donnybrook a couple of days ago," Ms Noble said.
"Whales are playing at the interface between the blue and brown water - pretty special!"
