A beach is a strip of land that lies along a body of water. It is composed of sand and sometimes gravel or shells. It can also contain seaweed and marine organisms, like crabs. Beaches are constantly changing, as the tide and waves move sediment from one place to another. This process is called coastal erosion. A beach that experiences constant coastal erosion is said to be in retreat.
Beaches are a very important part of the environment, as they provide shelter to marine organisms and wildlife. They also help regulate the temperature of the ocean. Beaches can also serve as a recreational area for humans. Beaches often host surfing, swimming, diving, sunbathing, and other outdoor activities.
Beaches can be made up of a variety of different materials, from fine sand to hard rock. They can be very dark in color, as in the case of volcanic beaches in the South Pacific, or they may be a vibrant yellow, as on the coast of Florida. Some beaches are even colored red, as in the case of coral reefs or lava flow that cooled quickly and deposited the mineral olivine.
A beach has many layers of sediment, including sand and rocks, that are deposited by the wind and waves. A beach can also have a lot of garbage, such as plastic bags or bottle caps. Beaches can be full of dead animals, such as birds or mammals, and may have a foul smell.
The shape of a beach is determined by its geological formation and climate. For example, beaches in colder climates are usually narrow and steep. In addition, they may have a lot of rounded sand grains. On the other hand, beaches in warmer climates are generally wider and flatter, and they have less rounded sand grains.
There are many ways to protect a beach. One way is to reduce pollution, such as reducing the amount of garbage that washes onto the beach. Beachgoers should also leave live animals, such as birds and marine mammals, alone. This way, they will not be harmed by humans or other animals.
Another way to protect a beach is by limiting human activities. This includes keeping pets off the beach and not taking shells, live animals, or other items from the beach. People should also avoid building structures on or near a beach, as this can cause erosion.
A beach may also be protected by sand nourishment, which is the addition of new sand to an existing beach. This is done to increase recreational uses or to slow the rate of shore erosion. Beach nourishment is a controversial practice, as there are concerns that it can disrupt marine life. However, some scientists believe that it can be beneficial if used properly. In addition, beach nourishment can be beneficial if it is done in conjunction with other shore protection measures, such as seawalls or dikes.