Lagoon

A lagoon is a shallow body of water separated from a larger body of water by barrier islands, coral reefs, or other natural barriers. Lagoons are commonly found along coastlines and can be classified into two main types: coastal lagoons and atoll lagoons. They are important ecological zones, providing habitat for a wide variety of species and serving as nurseries for many marine organisms.

Types of Lagoons

Coastal Lagoons

Coastal lagoons are formed along coastlines where sandbars or barrier islands create a separation between the ocean and a shallow body of water. These lagoons are typically found in areas with low tidal ranges and gentle wave action. The water in coastal lagoons can be brackish, a mix of fresh and saltwater, due to the inflow of rivers and streams.

Lagoon in Crete

Atoll Lagoons

Atoll lagoons are found in the center of coral atolls, which are ring-shaped coral reefs that encircle a lagoon. These lagoons are typically deeper than coastal lagoons and are formed by the subsidence of volcanic islands. The coral reefs protect the lagoon from the open ocean, creating a calm and sheltered environment.

Formation

Lagoons are formed through a variety of geological processes. Coastal lagoons are often created by the accumulation of sand and sediment along the coast, forming barrier islands that enclose a body of water. Atoll lagoons are formed by the gradual sinking of volcanic islands, leaving a ring of coral reefs around a central lagoon.

Ecological Importance

Lagoons are ecologically significant as they provide habitat for a diverse range of species. They serve as breeding grounds and nurseries for fish, birds, and other wildlife. The calm and sheltered waters of lagoons support seagrass beds and mangroves, which are crucial for maintaining biodiversity and protecting coastlines from erosion.

Lagoon from space

Human Impact

Human activities such as urban development, pollution, and climate change pose significant threats to lagoon ecosystems. Coastal development can lead to habitat destruction, while pollution from agricultural runoff and sewage can degrade water quality. Climate change can alter the hydrology of lagoons, affecting their ecological balance.

Notable Lagoons

• The Venice Lagoon in Italy is one of the most famous lagoons in the world, known for its historical significance and unique architecture.
• The Lagoa dos Patos in Brazil is the largest lagoon in South America, providing important habitat for migratory birds.
• The Bora Bora lagoon in French Polynesia is renowned for its stunning beauty and vibrant marine life.

Venice Lagoon

Related Pages

• Estuary
• Coral reef
• Barrier island
• Wetland