66 Barrier Island Facts: Find Out Why They Are Important

Barrier islands are formed when there is a continual deposition of sand, and they are enclosed by large water bodies.

Barrier islands are extended paths along the coastline where persistent ocean waves and wind action influence them. Incessant wave action leads to multiple barrier islands being formed.

People find themselves both fascinated by and afraid of resplendent shores enveloped by salt marshes, sand dunes, and abundant flora. Barrier islands act as a protective layer for the ecosystem of marshes and lagoons against fluctuating sea levels.

Numerous theories have been discussed by various scientists about the evolution of barrier islands for more than a century. The coastal research has led us to believe that there are multiple elements at work when it comes to the formation of barrier islands. Barrier islands also play a significant role in beach nourishment.

Facts About Barrier Islands

Barrier islands have been formed over thousands of years, so let's see how these amazing islands coexist with multiple topographical features.

• Each barrier is an extensive stretch of land that runs parallel to the mainland coast, which in turn protects the coast from waves and preserves the inland ecosystem of barrier islands.
• Barrier islands are under the constant influence of tidal waves and wind patterns, bringing sediments that can change and erode the island.
• Coastal sand dunes are a prominent facet of these islands.
• Nearly 10% of Earth's continental shorelines are made up of barrier islands.
• Every continent has barrier islands on its edges except Antarctica.
• There are a total of 2,500 barrier islands in the world.
• These islands are susceptible to weather changes, so they actively flourish or dissolve.
• With the improved technology of satellite imagery, scientists have been able to record their changes.
• The world's longest continuous chain of barrier islands is in Brazil.
• There are a total of 54 islands that are spread across 350 mi (570 km) along the Atlantic coast.
• The Arctic is home to approximately 13% of the world's barrier islands.
• The lengths of these islands are shorter when compared to the other islands.
• The islands are depositional landforms created by the movement of water, wind, and ice through the channels of sand, soil, and rock system.
• These islands face constant topographical changes which are due to various factors like strong currents, hurricanes, and rising human activity.
• In the United States, these islands are along the Gulf Coast and Atlantic Coast, extending until Long Island, New York.
• A few of them are Padre Island in Texas (the world's longest barrier island), Florida's Captiva and Sanibel Islands, North Carolina's Cape Hatteras, and Maryland's Assateague.
• There are no barriers along the Pacific Coast of the USA.

Importance Of Barrier Islands

Since our Earth has evolved for millions of years, there are innumerable characteristics that are alluring and mysterious in their own way. All these facets of our planet work interdependently, nurturing various ecosystems.

• A barrier island acts as a barrier between the mainland and the ocean or the sea.
• They work quite effectively in protecting the mainland, lagoons, and marshes from the sea currents, tropical storms, and hurricanes.
• The estuaries and marshes developed behind the barrier islands are home to many terrestrial plants and animal life.
• These include marine species and bird species (even some endangered species).
• Marine species such as shellfish, oysters, sea turtles, and fishes are heavily dependent on such islands, and nesting birds take shelter there as well.
• Animals such as snakes, skunks, opossums, raccoons, and foxes also commonly reside there.
• Marshes are a prominent and influencing feature of such islands since they trap and filter pollutants and sediments.
• Since Mother Nature is exceptional at everything she does, the barriers are a gorgeous sight to behold. Their aesthetic and scenic dispositions have drawn people from across the globe as they appreciate and visit them.
• Human footprints and their continual encroachment upon these lands have resulted in their disruption.
• Building infrastructures on such islands can be dangerous to both nature and humans alike.
• The ecosystems of barriers are often fragile, and since the water regularly permeates these sand grains, there is the development of prokaryotic bacteria.
• Anaerobic bacteria help in the decomposition of organic matter coming from expired plants, animals, and sediments.

The Formation Of Barrier Islands

Barrier island formation can take up thousands of years. Even after that, ongoing alterations take place, geologically relentless in their actions. So let's find out how they form.

• For the development of each barrier island, the tidal range needed is between small to moderate.
• Sea level and its currents act as an important part of the growth of such islands.
• Tidal ranges of coasts are further classified into three categories: Microtidal is 0-6.5 ft (0-2 m), Mesotidal is 6.5-13 ft (2-4 m), and Macrotidal is greater than 13 ft (4 m).
• A barrier island is formed alongside Microtidal coasts as they are quite persistent in their development.
• Many theories came forward to know how such barrier land formed.
• A single theory isn't enough to understand their development. Scientists gave three crucial theories.
• The Offshore Bar Theory, for instance, was given by a French Geologist named Elie de Beaumont in 1845.
• It said that the sea level waves which were going in deep water swirled the sand, and when the waves lost their strong currents, they deposited the sand; these bars then rose vertically, forming a barrier island.
• Spit Accretion Theory was given by Grove Karl Gilbert, an American Geologist, in 1885.
• He claimed that sediments of the barrier were unloaded from a long shore resulting in spits; the pattern was extended by storm waves which in turn led to the barrier being formed.
• The Submergence Theory given by William John McGee in 1890 claimed that the Gulf and American East Coast were experiencing submergence.
• Ages of coastal and sedimentary stratigraphy proved his theory to be incorrect.
• Each barrier island is a unique nexus of geologic changes which determine the present location and future of every barrier island.
• Rising sea levels give birth to barrier islands and the islands are formed at the mouth and end of river valleys.
• The collective sediments can also create a delta.
• Sea level changes, regional tectonics, climate, and vegetation these factors influence barrier islands' formations.
• The Northern Hemisphere has a total of 74% of the barrier islands of the world; most of them are situated in high-latitude climate zones.
• Regular storms are faced by the Arctic and Temperate Coast while Tropical areas are subjected to fewer storms, under such conditions, sand beaches are formed.

Examples Of Barrier Islands

The barriers are distributed along the world's coastlines. They are embellished and modified according to the brilliance of nature and captivate our curiosity.

• The United States has stable coasts with relief areas and estuaries.
• These barrier chains form in the regions of low tectonic activity, flat terrain, and possibly near river deltas.
• The United States alone accounts for a total of 450 of them.
• The United States barriers are scattered along Florida, Maine, and Texas.
• Dauphin Island is an exquisite island in Alabama. It secures most of Alabama's natural coastal resources and is the primary shelter for many migratory birds.
• The island allows commercial fishing and recreational activities, attracting global tourists.
• The island is also home to 1,200 people and a major bird sanctuary as well.
• Assateague Island stretches across 37 mi (60 km), two-thirds of it is in Maryland, and a third is in Virginia.
• Home to glorious feral horses, the two are managed by National Park Service and Chincoteague Volunteer Fire Company.
• The horses came there with ranchers during the 17th century.
• The world's longest barrier island is the Padre Island of Texas, which covers 113 mi (182 km), in the west, bordering Laguna Madre, and in the east, the Gulf of Mexico.
• It inhabits 16 wildlife species, including the world's smallest (Endangered) sea turtle species known as Kemp's ridley.
• Padre Island is home to 380 birds as well.
• The Great Barrier Island in New Zealand (outer Hauraki Gulf) is 62 mi (100 km) long.
• New Zealand's sixth-largest island gives residence to a total of 939 people who depend on farming and tourism.
• Since natural erosions and human activity have further degraded the inception of such barriers, to protect them, we must limit the activities around them.
• Every island acts as a preventive shield against the sea, but sometimes the currents can result in a breach.
• For instance, Hurricane Sandy in 2012 further divided Fire Island.
• Storms can corrode beaches and sand dunes.
• Leftover barriers are more prone to destruction.
• Prevention of excessive human activity, strict mandatory laws, and long-term conservation planning can help in securing the future of the barrier islands.