The human fascination with the sea and beach is rooted in history. According to John Gillis, professor of history at Rutgers University and author of The Human Shore: The Seacoast in History, the beach has evolved from a site of sustenance to a popular recreational area. Beaches and Coney Island became hot spots for sport activities. A beach, once a source of poverty and helplessness, entered the collective imagination of Europeans as a place of escape and recreation. It was even thought of as an ex nihilo creation by humankind to escape from their dreary and stressful lives.
But beaches aren’t the only places affected by man-made construction. These structures have a profound impact on the landscape and the character of a beach. Moreover, man-made structures such as dams and roads have accelerated sea level rise, and some beaches have even been completely submerged. Beachfront flora are a major part of coastal defense, trapping and enriching sand particles. These plants also prevent erosion from high winds, freak waves, and subsiding floodwaters.
The size of sand on a beach depends on the energy of waves and the material furnished by the water. Higher waves on a beach create coarser sand because the waves scour smaller grains offshore. On the other hand, dune sand is consistently finer grained than the sand of any adjacent beach. This is because the wind carries only fine grains of sand. Therefore, the shape of a beach is based on the nature of the waves.
Beaches come in many shapes and sizes. Some are wide and long, while others are narrow and gently sloping. Some contain a lot of shells, while others don’t. When visiting a beach, it’s worth returning to see how its width changes over time, due to an invisible force of nature. Other forms of landforms are often visible, such as tree stumps, outcrops of mud, rocks, and cliffs.
In addition to the shape of a beach, its material composition also depends on the kind of wave action on the shore. Large rocks and other sediments will be deposited on the coastlines of areas with energetic wind systems. Longshore currents will transport these finer sediments to calmer regions. On the other hand, protected coasts will create mud flats and mangrove forests. This in turn will affect the shape of the beach. There are many factors that determine how a beach looks like.
Beaches differ in color. Some are red, green, or black. Some beaches are even pink! The colors of the sand are determined by the geology of the surrounding area. Black basalt beaches, for example, have black sand, while white beaches are made of coral and white quart. Most of the beach sand comes from the sea, where waves break up rocks into sand-sized pieces. Moreover, the sand in beaches in tropical regions is made up of tiny particles of weathered quartz from the Appalachians.
While there is no single way to fully restore a beach ecosystem, it has been shown that frequent episodes of nourishment hinder the recovery of the beach community. Sand crab larvae, for instance, can recolonize a beach within a year after being exposed to seawater. In the absence of nourishment, this process may take many years. So, recolonizing a beach after nourishment is essential to the health of the entire ecosystem.