What is turning the ocean red in Manhattan Beach?

A red tide is causing the ocean to turn a rusty red in Manhattan Beach for the past few days, last seen north of the pier on Sept. 9, 2019.(Photo courtesy of Wayne Powell)
A red tide is causing the ocean to turn a rusty red in Manhattan Beach for the past few days, last seen north of the pier on Sept. 9, 2019.(Photo courtesy of Wayne Powell)SoundThe gallery will resume insecondsA red tide is causing the ocean to turn a rusty red in Manhattan Beach for the past few days, last seen north of the pi