Marginal sea facts for kids
A marginal sea is a part of a larger ocean that is found near the land. Think of it as a bay or gulf, but much bigger! These seas are partly surrounded by land, like continents or chains of islands. They are also usually shallower than the open ocean.
Marginal seas are important because they are often where rivers meet the ocean, bringing nutrients that help many sea creatures thrive. They are also busy places for fishing, shipping, and recreation.
Contents
What Makes a Sea "Marginal"?
A marginal sea is a section of an ocean that is next to a continent. It's often separated from the main ocean by islands, peninsulas, or underwater ridges. This separation means that the water in a marginal sea can be a bit different from the open ocean. For example, it might be warmer, colder, or have different levels of salt.
How They Form
Most marginal seas are located on a continental shelf. This is the underwater edge of a continent that slopes gently from the coastline. The presence of landforms like islands or underwater mountain ranges helps to create the boundaries of these seas.
Characteristics of Marginal Seas
Marginal seas often have:
- Shallower water: They are generally not as deep as the vast open ocean.
- Different water properties: The temperature, saltiness (salinity), and even the amount of oxygen in the water can vary from the main ocean. This is often due to freshwater flowing in from rivers or less mixing with the deep ocean currents.
- Rich marine life: Because they are often shallower and receive nutrients from land, marginal seas are usually home to a wide variety of plants and animals. Many important fishing grounds are found in these areas.
Examples of Marginal Seas
There are many marginal seas around the world. Here are a few well-known examples:
Atlantic Ocean Marginal Seas
- Caribbean Sea: Located south of North America, it's partly enclosed by the islands of the Caribbean and the coasts of Central and South America. It's famous for its warm waters and coral reefs.
- North Sea: Found between Great Britain, Scandinavia, and mainland Europe. It's a busy shipping route and an important area for fishing and oil exploration.
- Mediterranean Sea: Almost completely surrounded by Europe, Africa, and Asia, it connects to the Atlantic through the narrow Strait of Gibraltar. It's known for its long history and diverse cultures along its shores.
Pacific Ocean Marginal Seas
- South China Sea: A large marginal sea in the Pacific, bordered by China, Vietnam, the Philippines, and other countries. It's a vital shipping lane.
- Bering Sea: Located between Alaska and Siberia, it connects the Pacific and Arctic Oceans. It's known for its harsh weather and rich wildlife.
- Coral Sea: Off the northeast coast of Australia, famous for the Great Barrier Reef, the world's largest coral reef system.
Indian Ocean Marginal Seas
- Arabian Sea: Part of the Indian Ocean, bordered by the Arabian Peninsula and India. It's an important trade route.
- Bay of Bengal: Located east of India and west of Myanmar, it's the largest bay in the world.
Importance of Marginal Seas
Marginal seas are very important for both nature and people.
Ecosystems
They are often home to unique and diverse ecosystems. The shallower waters and proximity to land mean they receive more sunlight and nutrients, which helps marine plants like seaweed and phytoplankton grow. These plants form the base of the food web, supporting everything from small fish to large whales. Many species of fish, crabs, and shellfish live in these areas, making them vital for marine biodiversity.
Human Activities
- Fishing: Many of the world's most productive fishing grounds are found in marginal seas. This provides food and jobs for millions of people.
- Shipping and Trade: Their location near land makes them crucial for international shipping and trade. Many major ports are located along the coasts of marginal seas.
- Recreation and Tourism: With their beautiful coastlines and often calmer waters, marginal seas are popular spots for swimming, boating, diving, and other water sports. This supports a large tourism industry in many coastal regions.
- Energy Resources: Some marginal seas, like the North Sea, contain valuable oil and natural gas reserves beneath their seafloor.
Related pages
Images for kids
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The Norwegian Sea
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The Irish Sea
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The Arabian Sea as a marginal sea of the Indian Ocean.
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Coral Sea
See also
In Spanish: Mar marginal para niños
