Pink Mat Algae

Found in places of high energy wave action, growing in dense patches of matt like turf, over large areas of coral and rocky reefs. Looks very much like a large doormat. Varies in colour.
Length - spreading

As many as 9000 species of algae are spread across the worlds oceans, some can be as much as 30 metres across while others are just a slippery scum over rocks.
Algae grows wherever there is enough light and life supporting conditions.
They support a huge number of marine life both for food and as a home.