Why is the Great Salt Lake half red and half blue?

A railroad causeway built in 1959 cut Utah’s Great Salt Lake into two very different lakes, ecologically speaking, as seen in this striking drone footage posted by ABC News on Wednesday. The water north of the causeway is a deep red, reflecting its highly saline chemistry.Striking drone footage shows the stark split of Utah's Great Salt Lake—with one side a deep pink and the other a cool blue due to different levels of salinity. https://t.co/q7G3TRWdAT pic.twitter.com/jiP51srWPD&mdas