Explore at Low Tide

The intertidal zone is a challenging place to live! Things at home on this part of the shore must be able to survive being underwater, in dry air, hot, cold, buffeted by waves, covered in salt, washed by fresh rainwater, and predated by both land and sea animals. Some animals, such as barnacles, avoid trouble by closing tightly when the tide goes out. Other animals, such as small fish, find shelter beneath rocks in pools. Life is often a balance between getting enough to eat and not being exposed to conditions too harsh to survive. For example, algaes (seaweeds) need sunlight to photosynthesize, so they need to be close to the surface where there is plenty of light, but if they are too high up on the shore, they will spend so much time out of the water during low tide that they dry out. Wildlife in the intertidal zone are often organized in layers. Each layer is filled things that adapted to spend more or less time out of the ocean. Because the water in Sitka Sound changes by as much as 16 vertical feet between high and low tide, and there is a large, gently sloping delta at the mouth of Indian River, there are wide tidal flats to explore in the park. Close observation of intertidal life reveals a wide variety of survival strategies. Sitkans take advantage of all that variety. Though harvesting is generally not allowed on park shores, many of the things you find there are edible. According to a Tlingit saying, "When the tide is out, the table is set."