An archipelago is an area that contains a chain or group of islands scattered in lakes, rivers, or the ocean.
Formed in depressions along the shoreline of rocky coasts, tide pools are filled with seawater that gets trapped as the tide recedes. While these small basins at the ocean’s edge typically range from mere inches to a few feet deep and a few feet across, they are packed with sturdy sea life such as snails, barnacles, mussels, anemones, urchins, sea stars, crustaceans, seaweed, and small fish.