Low and sub tidal zones where wave action is less severe During low tide, you can find them in tide pools or damp surfaces where they scrape off and eat algae, especially kelp They also crawl into cuplike depressions in the rock made deeper by sea urchins over many generations Sea urchins have a hard shellPredicting the Extreme Low Tides As there is a regular, predictable tidal cycle it is easy enough to predict when that extreme low tide event will occur It will be roughly 6 hours BEFORE or AFTER the highest point of a Spring Tide, and local factors (shape of the coastline and underwater features) will affect which one of these two low tides will be the lowest · The lower littoral zone designation is used to refer to the part of the intertidal zone which is submerged most of the time, save for periods of low tide The lower littoral zone is the region of the littoral zone closest to the sea, and because it is usually underwater it tends to fluctuate in temperature less often than the h...