Intertidal zones exist anywhere the ocean meets the land, from steep, rocky ledges to long, sloping sandy beaches and mudflats that can extend for hundreds of meters. Four physical divisions, each with distinct characteristics and ecological differences, divide the intertidal zone. They are the:
Sea creatures arrange themselves vertically in the intertidal zone depending on their abilities to compete for space, avoid predators from above and below, and resist drying out. Residents of the higher intertidal zones can either close themselves up in their shells to remain moist and ward off predators, or are mobile enough to retreat to a submerged zone when the tide goes out. In the lower parts of the intertidal zone, many plants and animals attach themselves in place and are very sturdy, very flexible, or otherwise well suited to stand up to wave energy.
Larger marine life, such as seals, sea lions, and fish, find foraging for food ideal at high tide in the intertidal zone, while a large variety of shorebirds, looking for their meals, stroll hungrily over the intertidal zone at low tide.
Take only photographs and leave only footprints! Empty shells are recycled and reused by animals such as hermit crabs. Seaweed tossed on the shore decomposes and recycles nutrients back into the marine ecosystem.
Last updated: 02/26/21
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