Threatened species of Porifera

5,000 living sponge species are known, of which 150 occur in freshwater and the rest in the sea. The survival of sponges, the most primitive of multicellular animals, may be threatened due to pollution, disease, exploitation, or hurricanes.

For centuries, sponges have been employed for both personal and household purposes; in the first half of the 19th century sponge fishing began on a commercial basis in the Mediterranean, and by the end of that century it was well established in the USA and some Caribbean islands. Currently Tunisia is the world's largest supplier of sponges. In 1986, a fungal disease attacked the sponge fishing areas of the eastern Mediterranean nearly destroying the population.