A beach is a stretch of land along a body of water made up of sand, gravel, cobbles, rocks, shells and other marine sediment. Beach material accumulates on a beach during periods of accretion and moves away from a beach during periods of erosion. A beach may be hundreds of meters long or very short and is always changing. The main way beaches change is when ocean currents carry sediment from one area to another. These sediments often contain sand, seaweed, marine organisms and even garbage.
Sandbars are natural sand formations that can occur near the coastline or out in open water. They play a critical role in coastal ecosystems and can serve as shallow habitat for fish, marine plants and crustaceans. Depending on where they are located, sandbars can also help protect beach areas from erosion and flooding and provide a safe place for people to swim.
A kayak is a small, narrow, human-powered, open-water seacraft that is propelled by paddles. It was invented by the Inuit, formerly known as Eskimos, of northern Arctic regions thousands of years ago. They used animal skin, especially seal skin, to create the kayaks which they called qajaq, meaning “hunter’s boat.”
Kayaks are a popular recreational activity both in the surf and out of it. In the surf, a kayak can be used to explore swell breaks that are too large for a traditional surfing board or for paddling to a breaking wave when waves are less than ideal. In the open water, a kayak can be used for touring and fishing.
In a kayak, the person sitting in it, or paddler, steers it by using a pair of oars. A curved piece of wood, known as a skeg, is attached to the center of the kayak for stability. Two or more oars can be attached to the skeg, with more oars providing more stability and power. Kayaks come in a variety of sizes and shapes. Small kayaks can be paddled by one person, while larger ones have space for a passenger.
Many of the same factors that can cause a beach to disappear can also make it grow. A beach can be built up or diminished by dams that prevent river sediment from reaching the coast or by removing sand from beaches for use in construction. Beaches are also affected by sea level rise, which has been a problem in some areas where rising sea levels have drowned many beaches.
Beaches are often polluted by raw sewage and other toxic waste. This contamination can affect the health and safety of beachgoers, particularly after a storm or following heavy rains. This type of pollution can be caused by runoff from urban areas, sewage leaks and other sources. In some cases, beaches are closed because of the dangers to public health. Beaches can also be damaged by boats, fishing nets and other debris. In addition, many beaches have been overrun by algae and other invasive species.