Lake Retba in Senegal is one of several pink lakes in the world. It's even saltier than the dead sea, and many locals there work as salt harvesters.
The pink colour comes from harmless microbes living in the water, which use strongly coloured pigments as a kind of sunscreen. Some of them use a type of photosynthesis which may have evolved independently of plants.
(Image credit: VCG Photo)
@jonlandrum It would be pretty handy! Unfortunately humans would need something different to plant chlorophyll. Plants produce so much sugar through photosynthesis that you'd rapidly get diabetes!