Die masker-voorstaanders beklemtoon dat die masker oor die neus en mond moet pas.

‘n Seester. Foto: National Geographical Society. Sea stars like this one are an important keystone species in tide pools. In fact, the concept of “keystone species” was developed by Dr. Robert Paine, who studied sea stars in their native environment in Makah Bay, Washington. Sea stars eat sea urchins, mussels, and other shellfish that have no other natural predators. Photograph by Stacy Tatman, My Shot