The Great Salt Lake’s Railroad Causeway

(via Amusing Planet) The salinity difference, caused by the railway causeway across the lake, has created two different ecosystems on the lake. The south arm is dominated by blue-green algae, which colors the water green. On the north arm, higher salt content has allowed the growth of the alga Dunaliella Salina. This alga and the beta-carotene and bacteria it releases (Haloarchaea) imbue the north arm water with a distinctive wine red color.