The shore is the part of an ocean that is closest to land. This means that the water is shallow and light can reach the bottom. The shore is always moving because there are waves crashing at all times. That is why almost no plants can live in this area of the water. Tides also rise and fall at the shore that means that sometimes parts of the shore can be exposed to air. This is why shore organisms have to be able to live in water and out of water. When some parts of the shore are exposed to air animals like mussels and periwinkle snails have to adapt. Periwinkle snails adapt by digging into moist sand and muscles adapt by closing their shells tight so they don't dry
