Littoral refers to the shallow area where water meets land, especially along ocean coastlines. When scientists study the littoral zone, they're examining the strip of shore between the high tide and low tide marks, where waves wash up and recede throughout the day.

This zone teems with life. Tide pools in the littoral zone contain crabs, sea stars, anemones, and small fish that have adapted to survive both underwater and exposed to air. Barnacles cement themselves to rocks in the littoral zone, and seabirds hunt for food there when the tide goes out.

The word can describe anything relating to this coastal area. A littoral country is one with a coastline, like the United States or Japan. Military planners talk about littoral warfare when discussing naval operations close to shore, where the water is shallow enough that submarines must be careful and ships can support troops on land.

The littoral zone matters enormously to ocean health. Many fish species spawn there, and it can help filter pollution before it reaches deeper waters. It's also where humans interact most directly with the ocean: building ports, enjoying beaches, and harvesting seafood. Scientists pay close attention to littoral zones because changes there often signal larger environmental shifts affecting the entire ocean.