A beach is a strip of land along the edge of a body of water, such as an ocean or a lake. It is composed of loose sediments such as sand, pebbles and shells. Beaches can be found all over the world and are popular locations for swimming, sunbathing, picnicking and playing various beach sports. They are also the habitat of many sea creatures, from tiny hermit crabs scurrying on the sand to beautiful starfish and other sea plants that thrive in shallow tide pools.
The shape of a beach depends on the composition and structure of the sediments that form it. Sediments that are finer in size tend to accumulate on the foreshore and may be transported inland by longshore currents. On the other hand, coarser particles tend to be carried offshore by waves and deposited on the reefs or in the headland sandbars. The erosion of rock offshore and the movement of sand from the surf zone can dramatically change the beach’s profile, location and size within hours or even days.
Waves can also affect the size of a beach by how they break. For example, a point break occurs when the swell passes over a section of jutting rock or headland and breaks in a distinct point. Reef breaks occur when the swell interacts with coral or rocky reef, and beach breaks happen when the rolling waves interact with the shallow sand banks of a beach.
In addition, the type of flora that grows on a beach can play an important role in its stabilization and resistance to erosion. Flora with network root systems can trap sand particles and prevent them from being washed away by the waves. These flora can also enrich the surface layer of dunes with nutrients and thereby increase their ability to resist erosion.
Beaches are also home to a variety of manmade objects. For instance, the beaches of the State of Washington are covered in driftwood and logs that have been cast ashore by storm waves and winds. The beaches of the Skeleton Coast in Namibia collect the bones of whales and seals as well as other debris from shipwrecks and other human activities. Beaches are also sometimes lined with garbage and litter that has washed ashore.
To protect beaches, people can reduce their waste and minimize the amount of material that ends up in the ocean. Leaving trash behind on the beach can choke animals that eat it, and floating plastic can block sunlight from reaching algae and other marine plants. Likewise, it is important not to remove shells or live animals from the beach, as doing so can harm these living organisms. It is also a good idea to avoid touching the seaweed known as Sargasso, as it can cause irritation and entanglement.