One of Mandurah's oldest dolphins passed away on the weekend.
Zero One, who was thought to be in his late 30s, survived several strandings and at least one shark attack.
Estuary Guardians Mandurah reported the death on their Facebook page.
"Yesterday elderly dolphin Zero One was found deceased in the lower reaches of the South Dandalup river, near where it meets the upper Murray River," the post read.
"01 was the senior member of (what seems to be) the highest ranking male alliance the King's Crew and still chasing the girls in his last weeks.
"It is likely 01 has fathered many of our present dolphins."

Cooloongup man accused of historical child sex offences dies just weeks before trial
Boat owners urged to make safety a priority this Easter
Mundijong man accused of attempting to procure children overseas for sexual activity
PM Anthony Albanese to address nation
Mandurah teacher who raped student to remain on bail
Man charged after allegedly exposing himself to girl on Transperth bus in Lakelands
Fire rips through Golden Bay home
Firefighters battle bushfire near Nambeelup
Alcoa Children's Festival cancelled due to severe weather