Since the existence of this species has been acknowledged only very recently, not much is known about the fluctuation in its population in various areas. However, the smaller numbers of this species could be a result of the chemicals that are released into the water bodies through the estuaries and river mouths, areas where the mimic octopus is generally found.
Read more at Buzzle: http://www.buzzle.com/articles/amazing-facts-about-the-mimic-octopus.html