The island is an accumulation of biogenic sediment similar to Heron Island, and it has been sufficiently stable to accumulate vegetation. A major component of the mobile sands of Bushy Island is Foraminifera, a type of amoeboid protist.
The island shares characteristics with Heron Island in terms of its biogenic sediment composition and vegetation accumulation. Like the mobile sands on Bushy Island, the sands of the island are rich in Foraminifera, an amoeboid protist.