The tropical marine embayment of Roebuck Bay includes 33 foot (10 meter) tides, mangrove forests (narrow dark bands that parallel the coast and border the reddish, upland region), and a large expanse of intertidal mudflats (gray region along the coast). The intertidal mudflats of Roebuck Bay and the surrounding coasts offers one of the best places in the world to view numerous species of migratory wader birds. Even though tourism is not the major source of income for the city yet, the local pearl industry is being challenged by the increasing annual tourist traffic through the region.