Oceans (Landforms)

Sandy Sepehri

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Library of Congress Cataloging-in-Publication Data Sepehri, Sandy. Oceans / Sandy Sepheri. p. cm. -- (Landforms) ISBN 978-1-60044-549-1 (Hard cover) ISBN 978-1-60044-710-5 (Soft cover) 1. Oceans--Juvenile literature. I. Title. GC21.5.S45 2008 551.46--dc22

What Are Oceans?

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The Atlantic Ocean

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The Pacific Ocean

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The Indian Ocean

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The Southern Ocean

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The Arctic Ocean

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Dangerous Oceans

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Beneath the Surface

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Amazing Sea Creatures

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Oceans in Danger

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Glossary

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Index

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Printed in the USA IG/IG

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What Are Oceans? The Earth is a very wet planet. About three-fourths of it is covered by an immense body of saltwater, called the World Ocean. Continents and islands divide this ocean into different areas of the world. For centuries, these waters were given a variety of names by explorers and together were known as “The World’s Oceans”. The North Atlantic, South Atlantic, North Pacific, South Pacific, Indian, Southern, and Arctic Oceans make up the seven major bodies of water.

Without the oceans, life on Earth would not be possible. Since the majority of the world’s plants and animals live in the oceans, the oceans play a major role in the food chain, and provide

food directly through the fishing industry. Oceans also affect weather and transportation. Before airplanes, traveling in ships was the only way to visit other lands. Today, most of the world’s goods are still transported over the oceans.

Did you know ocean water is 96% fresh water and 4% salts and other solids? The most common salt in ocean water is sodium chloride, also known as table salt.

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What Are Oceans? The Earth is a very wet planet. About three-fourths of it is covered by an immense body of saltwater, called the World Ocean. Continents and islands divide this ocean into different areas of the world. For centuries, these waters were given a variety of names by explorers and together were known as “The World’s Oceans”. The North Atlantic, South Atlantic, North Pacific, South Pacific, Indian, Southern, and Arctic Oceans make up the seven major bodies of water.

Without the oceans, life on Earth would not be possible. Since the majority of the world’s plants and animals live in the oceans, the oceans play a major role in the food chain, and provide

food directly through the fishing industry. Oceans also affect weather and transportation. Before airplanes, traveling in ships was the only way to visit other lands. Today, most of the world’s goods are still transported over the oceans.

Did you know ocean water is 96% fresh water and 4% salts and other solids? The most common salt in ocean water is sodium chloride, also known as table salt.

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ARCTIC OCEAN

The Atlantic provides the fishing industry with about 40 percent of the world’s catch, largely from the North Atlantic. Construction materials are made from the sand and gravel collected along this ocean’s shorelines. The Caribbean Sea and the Gulf of Mexico are popular tourist spots for diving, sailing, and underwater exploring.

NORTH ATLANTIC OCEAN

NORTH PACIFIC OCEAN

Equator SOUTH PACIFIC OCEAN

SOUTH ATLANTIC OCEAN

INDIAN OCEAN

SOUTHERN OCEAN

What’s the difference between an ocean and a sea? All oceans and seas are part of the same mass of saltwater. Areas called oceans are separated by continents. Areas called seas are smaller and partly surrounded by land.

North America Gulf of Mexico

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South America

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The North Atlantic lies north of the equator, with North America on its west and North Africa and Europe on its east. It is where hurricanes are born and has the most used ocean trade route in the world. Ships travel in shipping lanes to avoid collisions. To help them navigate, they receive radio reports of icebergs. Several offshore fields drill petroleum and natural gas. Tin and coal are mined from beneath the ocean floor off Great Britain.

Equator

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The Atlantic Ocean

Caribbean Sea

Why are icebergs dangerous to ships? Navigating around icebergs is very difficult because only onetenth of an iceberg appears above water—the rest is underwater where it can't be seen. Because of this, ships have hit icebergs and sunk from the damage.

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In 1492, Christoph er Columbus cross ed the Atlantic looking fo r India. He though t he had reached India w hen he landed on North America and mistakenly named the natives “Indians.” 7

ARCTIC OCEAN

The Atlantic provides the fishing industry with about 40 percent of the world’s catch, largely from the North Atlantic. Construction materials are made from the sand and gravel collected along this ocean’s shorelines. The Caribbean Sea and the Gulf of Mexico are popular tourist spots for diving, sailing, and underwater exploring.

NORTH ATLANTIC OCEAN

NORTH PACIFIC OCEAN

Equator SOUTH PACIFIC OCEAN

SOUTH ATLANTIC OCEAN

INDIAN OCEAN

SOUTHERN OCEAN

What’s the difference between an ocean and a sea? All oceans and seas are part of the same mass of saltwater. Areas called oceans are separated by continents. Areas called seas are smaller and partly surrounded by land.

North America Gulf of Mexico

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e

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Ra

South America

ai

The North Atlantic lies north of the equator, with North America on its west and North Africa and Europe on its east. It is where hurricanes are born and has the most used ocean trade route in the world. Ships travel in shipping lanes to avoid collisions. To help them navigate, they receive radio reports of icebergs. Several offshore fields drill petroleum and natural gas. Tin and coal are mined from beneath the ocean floor off Great Britain.

Equator

nt

The Atlantic Ocean

Caribbean Sea

Why are icebergs dangerous to ships? Navigating around icebergs is very difficult because only onetenth of an iceberg appears above water—the rest is underwater where it can't be seen. Because of this, ships have hit icebergs and sunk from the damage.

M

A

a pp

la

ou

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In 1492, Christoph er Columbus cross ed the Atlantic looking fo r India. He though t he had reached India w hen he landed on North America and mistakenly named the natives “Indians.” 7

The South Atlantic lies south of the equator, between the eastern coast of most of South America and the southwestern coast of Africa. The water in the South Atlantic circulates in a counter-clockwise direction because of the Coriolis effect. Petroleum and natural gas wells are drilled off the shores of Argentina and Brazil, and large diamond deposits are found along the southwestern coast of Africa.

Between the tips of South Africa and South America, are huge waves and strong winds, called the “Roaring Forties.” Along the floor of the Atlantic are optical fiber cables, providing global telecommunications. The spiny rock lobster is caught in South Atlantic waters. A large variety of penguins live along the coast of South America. One of these is the Gentoo, which lay their eggs in stone nests. A Gentoo penguin sitting on its eggs.

View of the Atlantic Ocean from Cape Point, South Africa.

What’s the Coriolis effect? It is a result of the Earth’s rotation, which moves the ocean to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. It is also why winds on the Northern Hemisphere rotate counterclockwise around the center of a cyclone and clockwise on the Southern Hemisphere.

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The Earth’s Zipper In the middle of the Atlantic floor is the Mid Atlantic Ridge, a mountain range wedged between two Earth plates, pulling in opposite directions and allowing the spread of the ocean floor.

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The South Atlantic lies south of the equator, between the eastern coast of most of South America and the southwestern coast of Africa. The water in the South Atlantic circulates in a counter-clockwise direction because of the Coriolis effect. Petroleum and natural gas wells are drilled off the shores of Argentina and Brazil, and large diamond deposits are found along the southwestern coast of Africa.

Between the tips of South Africa and South America, are huge waves and strong winds, called the “Roaring Forties.” Along the floor of the Atlantic are optical fiber cables, providing global telecommunications. The spiny rock lobster is caught in South Atlantic waters. A large variety of penguins live along the coast of South America. One of these is the Gentoo, which lay their eggs in stone nests. A Gentoo penguin sitting on its eggs.

View of the Atlantic Ocean from Cape Point, South Africa.

What’s the Coriolis effect? It is a result of the Earth’s rotation, which moves the ocean to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. It is also why winds on the Northern Hemisphere rotate counterclockwise around the center of a cyclone and clockwise on the Southern Hemisphere.

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The Earth’s Zipper In the middle of the Atlantic floor is the Mid Atlantic Ridge, a mountain range wedged between two Earth plates, pulling in opposite directions and allowing the spread of the ocean floor.

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ARCTIC OCEAN

NORTH ATLANTIC OCEAN

NORTH PACIFIC OCEAN

Equator

SOUTH PACIFIC OCEAN

SOUTH ATLANTIC OCEAN

INDIAN OCEAN

SOUTHERN OCEAN

The Pacific Ocean surrounds the Hawaiian Islands..

The Pacific Ring of Fire, a horseshoe shaped zone, is where 90 percent of the world’s earthquakes occur. This zone surrounds almost the entire Pacific Ocean running along the west coast of North American and the east coast of Asia. In the winter, the Northern Pacific water turns very cold—near freezing. Ice forms in the Arctic Ocean and drifts down the Bering Straight and into the Pacific Ocean. Industries include fishing, oil and gas production, and sand and gravel collection. Winter in the Northern

Pacific is dangerous to these industries. Waves can reach over 50 feet (15 m) and travel 2,000 miles (3,218 km) south to hit the islands of Hawaii and the southern west coast of the United States. Bering Sea

Russia

The Pacific Ocean The Pacific Ocean is the world’s largest body of water, covering about half the Earth. Its name, given by the Portuguese explorer Ferdinand Magellan, means “peaceful sea.” The North Pacific lies north of the equator, between the west coast of North America and the east coast of Asia. It surrounds the U.S. state of Hawaii and the Northern Mariana Islands. 10

Canada

Underwater Mountains Many of the geological features we know on land exist beneath the ocean, including mountains called seamounts. A seamount is a mountain on the ocean floor that does not reach the water’s surface. There are about 30,000 seamounts in the world.

North Pacific Ocean

United States Hawaiian Islands

This satellite photo shows giant icebergs, some as big as small towns, drifting south from the Bering Sea to the North Pacific Ocean.

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ARCTIC OCEAN

NORTH ATLANTIC OCEAN

NORTH PACIFIC OCEAN

Equator

SOUTH PACIFIC OCEAN

SOUTH ATLANTIC OCEAN

INDIAN OCEAN

SOUTHERN OCEAN

The Pacific Ocean surrounds the Hawaiian Islands..

The Pacific Ring of Fire, a horseshoe shaped zone, is where 90 percent of the world’s earthquakes occur. This zone surrounds almost the entire Pacific Ocean running along the west coast of North American and the east coast of Asia. In the winter, the Northern Pacific water turns very cold—near freezing. Ice forms in the Arctic Ocean and drifts down the Bering Straight and into the Pacific Ocean. Industries include fishing, oil and gas production, and sand and gravel collection. Winter in the Northern

Pacific is dangerous to these industries. Waves can reach over 50 feet (15 m) and travel 2,000 miles (3,218 km) south to hit the islands of Hawaii and the southern west coast of the United States. Bering Sea

Russia

The Pacific Ocean The Pacific Ocean is the world’s largest body of water, covering about half the Earth. Its name, given by the Portuguese explorer Ferdinand Magellan, means “peaceful sea.” The North Pacific lies north of the equator, between the west coast of North America and the east coast of Asia. It surrounds the U.S. state of Hawaii and the Northern Mariana Islands. 10

Canada

Underwater Mountains Many of the geological features we know on land exist beneath the ocean, including mountains called seamounts. A seamount is a mountain on the ocean floor that does not reach the water’s surface. There are about 30,000 seamounts in the world.

North Pacific Ocean

United States Hawaiian Islands

This satellite photo shows giant icebergs, some as big as small towns, drifting south from the Bering Sea to the North Pacific Ocean.

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The South Pacific is south of the equator, between the east coast of Australia and the west coast of South America. It has the most islands in the world, including New Guinea, the world’s second largest island. A natural passage, called the Strait of Magellan, cuts narrowly through the southern tip of South America, connecting the Atlantic and Pacific Oceans. It was first navigated by Ferdinand Magellan in 1520. The South Pacific is known for a major Australian tourist attraction, the Great Barrier Reef. It is the world’s largest coral reef and supports an abundance of sea life. This ocean is also known for its Australian angel sharks, which grab their prey with protruding jaws. This ocean also has black pearls, which are plucked from black-lipped oysters.

What Are Coral Reefs? Coral reefs are limestone structures found in shallow tropical marine waters. A diver explores the Great Barrier Reef.

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The South Pacific is south of the equator, between the east coast of Australia and the west coast of South America. It has the most islands in the world, including New Guinea, the world’s second largest island. A natural passage, called the Strait of Magellan, cuts narrowly through the southern tip of South America, connecting the Atlantic and Pacific Oceans. It was first navigated by Ferdinand Magellan in 1520. The South Pacific is known for a major Australian tourist attraction, the Great Barrier Reef. It is the world’s largest coral reef and supports an abundance of sea life. This ocean is also known for its Australian angel sharks, which grab their prey with protruding jaws. This ocean also has black pearls, which are plucked from black-lipped oysters.

What Are Coral Reefs? Coral reefs are limestone structures found in shallow tropical marine waters. A diver explores the Great Barrier Reef.

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Russia

Europe

The Indian Ocean The Indian Ocean is the third largest ocean. It lies south of Asia and north of Antarctica, with Africa on its west and Australia on its east. Most of it is in the tropical zone, where corals and red algae form islands and atolls. Its island nations include Madagascar, Comoros, Maldives, Mauritius, and Sri Lanka. It also includes volcanic islands, surrounded by coral reefs.

Asia Japan

Saudi Arabia

India

Africa

Sri Lanka Equator 0º

Indian Ocean Australia Madagascar

The Indian Ocean’s major sea routes connect the Middle East, Africa, and East Asia with Europe and the Americas. Forty percent of the world’s offshore oil drilling occurs in this ocean. As a result, oil pollution threatens the Arabian Sea, Persian Gulf, and Red Sea. Russia, Japan, South Korea, and Taiwan depend upon Indian Ocean marine life, mainly shrimp and tuna, for domestic consumption and export. Aerial view of an atoll located in the Indian Ocean.

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An oil drilling rig being assembled in the Indian Ocean.

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Russia

Europe

The Indian Ocean The Indian Ocean is the third largest ocean. It lies south of Asia and north of Antarctica, with Africa on its west and Australia on its east. Most of it is in the tropical zone, where corals and red algae form islands and atolls. Its island nations include Madagascar, Comoros, Maldives, Mauritius, and Sri Lanka. It also includes volcanic islands, surrounded by coral reefs.

Asia Japan

Saudi Arabia

India

Africa

Sri Lanka Equator 0º

Indian Ocean Australia Madagascar

The Indian Ocean’s major sea routes connect the Middle East, Africa, and East Asia with Europe and the Americas. Forty percent of the world’s offshore oil drilling occurs in this ocean. As a result, oil pollution threatens the Arabian Sea, Persian Gulf, and Red Sea. Russia, Japan, South Korea, and Taiwan depend upon Indian Ocean marine life, mainly shrimp and tuna, for domestic consumption and export. Aerial view of an atoll located in the Indian Ocean.

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An oil drilling rig being assembled in the Indian Ocean.

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The Southern Ocean

ARCTIC OCEAN

NORTH ATLANTIC OCEAN

NORTH PACIFIC OCEAN

Equator SOUTH PACIFIC OCEAN

SOUTH ATLANTIC OCEAN

INDIAN OCEAN

SOUTHERN OCEAN

Many animals find their food in the icy Antarctic Ocean. n

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Antarctica

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The Southern Ocean, also known as the Antarctic Ocean, lies at the bottom of the world. It encircles Antarctica and is the only ocean entirely in the Southern Hemisphere, meaning south of the equator. It’s the world’s fourth largest ocean and in winter, parts of it freeze around the shores of Antarctica. The wind and ocean swells break the ice into large pieces called pack ice or sea ice.

The Southern Ocean’s natural resources include fresh water from icebergs, sand and gravel, manganese nodules (for iron and steel production), valuable minerals, and possibly large oil and gas fields along the margin of Antarctica. Its major industry is fishing, and the tourist industry brings more than 10,000 visitors each year. Several breeds of penguin live along the coast of Antarctica, including the largest breed, the Emperor Penguin.

The continent of Antarctica is at the bottom of the Earth and can only be reached during the summer months. Bad weather and frozen seas make it too dangerous to get to in winter.

What is the largest glacier on Earth? It is Antarctica. Antarctica is known as a continent and a continental ice sheet or glacier.

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The Southern Ocean

ARCTIC OCEAN

NORTH ATLANTIC OCEAN

NORTH PACIFIC OCEAN

Equator SOUTH PACIFIC OCEAN

SOUTH ATLANTIC OCEAN

INDIAN OCEAN

SOUTHERN OCEAN

Many animals find their food in the icy Antarctic Ocean. n

Oce an

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A

Oce an

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Antarctica

tic rc

tic rc a t

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The Southern Ocean, also known as the Antarctic Ocean, lies at the bottom of the world. It encircles Antarctica and is the only ocean entirely in the Southern Hemisphere, meaning south of the equator. It’s the world’s fourth largest ocean and in winter, parts of it freeze around the shores of Antarctica. The wind and ocean swells break the ice into large pieces called pack ice or sea ice.

The Southern Ocean’s natural resources include fresh water from icebergs, sand and gravel, manganese nodules (for iron and steel production), valuable minerals, and possibly large oil and gas fields along the margin of Antarctica. Its major industry is fishing, and the tourist industry brings more than 10,000 visitors each year. Several breeds of penguin live along the coast of Antarctica, including the largest breed, the Emperor Penguin.

The continent of Antarctica is at the bottom of the Earth and can only be reached during the summer months. Bad weather and frozen seas make it too dangerous to get to in winter.

What is the largest glacier on Earth? It is Antarctica. Antarctica is known as a continent and a continental ice sheet or glacier.

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During the winter, the amount of pack ice doubles. It is dark 24 hours a day and the skies are clear and cold. The pack ice is heaviest during the months of March and April and measures between 8 and 20 inches (20 to 50 cm). Navigation by ships is nearly impossible during this period. In the summer months, ships can travel into this region although it is still dangerous. The water temperature stays near freezing all year round making

ARCTIC OCEAN

NORTH ATLANTIC OCEAN

NORTH PACIFIC OCEAN

Equator SOUTH PACIFIC OCEAN

SOUTH ATLANTIC OCEAN

INDIAN OCEAN

SOUTHERN OCEAN

Ocean Phytoplankton Bloom

The Arctic Ocean

Ar

ct

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North Pole

The Arctic Ocean is the smallest ocean, positioned on top of the world, between Europe, Asia, and North America. It is the shortest air route between the Pacific coast of North America and Europe. Its ocean floor has the world’s highest percentage of continental shelf (about 50%). Throughout the year, parts of the Arctic Ocean are covered by floating pack ice. 18

survival difficult for anyone falling into its waters. However there are a number of animals that inhabit this cold, ocean region. Walruses, whales, polar bears, and many bird species live and feed off these waters. The beginnings of this cold water food chain starts with phytoplankton. These are microorganisms that feed krill which in turn, feeds many sea animals including whales.

A whale feeds on krill. A krill feeds on phytoplankton.

This giant phytoplankton bloom in the Arctic Ocean can be seen from a satellite.

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During the winter, the amount of pack ice doubles. It is dark 24 hours a day and the skies are clear and cold. The pack ice is heaviest during the months of March and April and measures between 8 and 20 inches (20 to 50 cm). Navigation by ships is nearly impossible during this period. In the summer months, ships can travel into this region although it is still dangerous. The water temperature stays near freezing all year round making

ARCTIC OCEAN

NORTH ATLANTIC OCEAN

NORTH PACIFIC OCEAN

Equator SOUTH PACIFIC OCEAN

SOUTH ATLANTIC OCEAN

INDIAN OCEAN

SOUTHERN OCEAN

Ocean Phytoplankton Bloom

The Arctic Ocean

Ar

ct

i

c

North Pole

The Arctic Ocean is the smallest ocean, positioned on top of the world, between Europe, Asia, and North America. It is the shortest air route between the Pacific coast of North America and Europe. Its ocean floor has the world’s highest percentage of continental shelf (about 50%). Throughout the year, parts of the Arctic Ocean are covered by floating pack ice. 18

survival difficult for anyone falling into its waters. However there are a number of animals that inhabit this cold, ocean region. Walruses, whales, polar bears, and many bird species live and feed off these waters. The beginnings of this cold water food chain starts with phytoplankton. These are microorganisms that feed krill which in turn, feeds many sea animals including whales.

A whale feeds on krill. A krill feeds on phytoplankton.

This giant phytoplankton bloom in the Arctic Ocean can be seen from a satellite.

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Dangerous Oceans Ocean waters are constantly moving. As wind blows over the oceans, it causes the water to move in circular patterns, called

Ocean currents carried this ship to shore where it sits rotting in the ocean’s saltwater.

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ocean currents. Currents can help us move from country to country but can also send us adrift into the middle of the sea.

As the wind blows over the ocean’s surface, it creates waves. If the wind blows long and hard enough, the waves get bigger. They can grow to 50 feet (15 m) in size. Big waves can sink ships and damage coastlines.

More dramatic forms of ocean activity are tsunamis and hurricanes. Tsunamis are large waves caused by earthquakes and landslides. In 2004 a massive earthquake triggered a tsunami in the Indian Ocean killing nearly 300,000 people. Hurricanes develop from tropical storms into powerful, rotating storms of strong winds and rain, powerful enough to destroy life and towns. Because its wind rotates in a cyclone, hurricanes are also called tropical cyclones. Hurricanes that form in the Western Pacific Ocean are called typhoons.

2004 tsunami damage viewed from the air.

A large hurricane viewed from space.

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Dangerous Oceans Ocean waters are constantly moving. As wind blows over the oceans, it causes the water to move in circular patterns, called

Ocean currents carried this ship to shore where it sits rotting in the ocean’s saltwater.

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ocean currents. Currents can help us move from country to country but can also send us adrift into the middle of the sea.

As the wind blows over the ocean’s surface, it creates waves. If the wind blows long and hard enough, the waves get bigger. They can grow to 50 feet (15 m) in size. Big waves can sink ships and damage coastlines.

More dramatic forms of ocean activity are tsunamis and hurricanes. Tsunamis are large waves caused by earthquakes and landslides. In 2004 a massive earthquake triggered a tsunami in the Indian Ocean killing nearly 300,000 people. Hurricanes develop from tropical storms into powerful, rotating storms of strong winds and rain, powerful enough to destroy life and towns. Because its wind rotates in a cyclone, hurricanes are also called tropical cyclones. Hurricanes that form in the Western Pacific Ocean are called typhoons.

2004 tsunami damage viewed from the air.

A large hurricane viewed from space.

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Main Volcano Cone

Continental Shelf Lava Flow Caldera Ridge

Continental Shelf Continental Slope

There are mountains and valleys below the ocean’s surface. They are created by active volcanoes shown in this re-creation of the ocean floor. The light blue color represents the continental shelf around the world.

Deep Ocean Basin

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Beneath the Surface

Beneath the ocean surface live the majority of the world’s plants and animals. Dramatic, underwater landforms lie throughout three major areas: the continental shelf, the continental slope, and the deep ocean basin. The continental shelf is the underwater section of the continents, extending for several hundred miles in some areas. It has hills, ridges, and canyons. At about 430 feet (131 m) deep, the continental shelf drops off into a steep slope, called the continental slope, which connects the continental shelf to the oceanic crust.

The slope descends about 12,000 feet (3.65 km) to the deep ocean basin, which also has features like those on land, but much larger, including plains and

mountains. Beneath the ocean floor, the earth’s crustal plates continue to move, creating hydrothermal vents and volcanoes.

o u t w h a t ’s u n d n i f der us p l e our h s r o ce e r o l an p s. Ex 23

Main Volcano Cone

Continental Shelf Lava Flow Caldera Ridge

Continental Shelf Continental Slope

There are mountains and valleys below the ocean’s surface. They are created by active volcanoes shown in this re-creation of the ocean floor. The light blue color represents the continental shelf around the world.

Deep Ocean Basin

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Beneath the Surface

Beneath the ocean surface live the majority of the world’s plants and animals. Dramatic, underwater landforms lie throughout three major areas: the continental shelf, the continental slope, and the deep ocean basin. The continental shelf is the underwater section of the continents, extending for several hundred miles in some areas. It has hills, ridges, and canyons. At about 430 feet (131 m) deep, the continental shelf drops off into a steep slope, called the continental slope, which connects the continental shelf to the oceanic crust.

The slope descends about 12,000 feet (3.65 km) to the deep ocean basin, which also has features like those on land, but much larger, including plains and

mountains. Beneath the ocean floor, the earth’s crustal plates continue to move, creating hydrothermal vents and volcanoes.

o u t w h a t ’s u n d n i f der us p l e our h s r o ce e r o l an p s. Ex 23

Amazing Sea Creatures

A Clownfish

With more than one million known species of plants and animals, the ocean is full of amazing creatures. Among them are sponges, jellyfish, coral, anemone (with names like brain, clubbed finger, and flower pot), sea stars, crustaceans (crabs, shrimp and lobsters), mollusks (clams, oysters, squid, and more), seahorses, reef fish, sharks, and rays, marine reptiles (sea turtles), and marine mammals.

Purple Tube Sponges

Jelly Fish

A Sea Turtle

A Spotted Eagle Ray

A Manatee Marine mammals are warm-blooded animals that breathe air and nurse their young. This group of sea life includes whales, seals, dolphins, porpoises, and manatees, also called sea cows. Warm-blooded animals do not have the ability to change their body temperature to adapt to their environments. What protects marine mammals from freezing in icy water is their blubber—a layer of fat beneath their skin.

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Amazing Sea Creatures

A Clownfish

With more than one million known species of plants and animals, the ocean is full of amazing creatures. Among them are sponges, jellyfish, coral, anemone (with names like brain, clubbed finger, and flower pot), sea stars, crustaceans (crabs, shrimp and lobsters), mollusks (clams, oysters, squid, and more), seahorses, reef fish, sharks, and rays, marine reptiles (sea turtles), and marine mammals.

Purple Tube Sponges

Jelly Fish

A Sea Turtle

A Spotted Eagle Ray

A Manatee Marine mammals are warm-blooded animals that breathe air and nurse their young. This group of sea life includes whales, seals, dolphins, porpoises, and manatees, also called sea cows. Warm-blooded animals do not have the ability to change their body temperature to adapt to their environments. What protects marine mammals from freezing in icy water is their blubber—a layer of fat beneath their skin.

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Oceans in Danger

Size comparison of a whale shark to a human.

Ocean Giants The largest animal on Earth is a marine mammal—the blue whale. The largest blue whale accurately weighed was a female, weighing 196 tons (178 m The heart of a blue whale is about the size of a small car! tons)—about the weight of 33 African elephants! The longest blue whale measured was 98 feet (29 m) long—about the length of two school buses. At birth, a blue whale weighs as much as an adult hippopotamus. The largest fish on Earth is the whale shark. Its huge mouth can be up to five feet (1.5 m) wide. Adaptation Down in the deep abyss, where there’s no sunlight, sea creatures have developed special adaptations to their environment. Some use a light, called bioluminescence, to attract prey and scare predators.

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The oceans are being threatened by a variety of hazards, including untreated sewage, plastic debris, toxic pollutants, oil pollution, radioactive waste, a thinning ozone layer, and global warming. In fact, growing areas are becoming dead zones—large areas without enough oxygen to support sea life. Dead zones result from untreated sewage (containing toxic chemicals, heavy metals and excreted pharmaceuticals), fertilizer, and plastic debris. More than a million seabirds, 100,000 mammals, and sea turtles die each year from consuming plastic debris. The thinning ozone layer (from man-made chlorofluorocarbons) allows increased solar ultraviolet radiation, which reduces phytoplankton (part of the food chain). Global warming partially comes from the buildup of greenhouse gases. It raises the ocean’s acidity and kills coral reefs—home to a variety of sea life.

What Can You Do? Keep our shorelines clean and don’t throw garbage into gutters because they lead to waterways. Learn about ocean preservation. Your efforts can help change the world!

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Oceans in Danger

Size comparison of a whale shark to a human.

Ocean Giants The largest animal on Earth is a marine mammal—the blue whale. The largest blue whale accurately weighed was a female, weighing 196 tons (178 m The heart of a blue whale is about the size of a small car! tons)—about the weight of 33 African elephants! The longest blue whale measured was 98 feet (29 m) long—about the length of two school buses. At birth, a blue whale weighs as much as an adult hippopotamus. The largest fish on Earth is the whale shark. Its huge mouth can be up to five feet (1.5 m) wide. Adaptation Down in the deep abyss, where there’s no sunlight, sea creatures have developed special adaptations to their environment. Some use a light, called bioluminescence, to attract prey and scare predators.

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The oceans are being threatened by a variety of hazards, including untreated sewage, plastic debris, toxic pollutants, oil pollution, radioactive waste, a thinning ozone layer, and global warming. In fact, growing areas are becoming dead zones—large areas without enough oxygen to support sea life. Dead zones result from untreated sewage (containing toxic chemicals, heavy metals and excreted pharmaceuticals), fertilizer, and plastic debris. More than a million seabirds, 100,000 mammals, and sea turtles die each year from consuming plastic debris. The thinning ozone layer (from man-made chlorofluorocarbons) allows increased solar ultraviolet radiation, which reduces phytoplankton (part of the food chain). Global warming partially comes from the buildup of greenhouse gases. It raises the ocean’s acidity and kills coral reefs—home to a variety of sea life.

What Can You Do? Keep our shorelines clean and don’t throw garbage into gutters because they lead to waterways. Learn about ocean preservation. Your efforts can help change the world!

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Arctic Ocean

Arctic Ocean

Baltic Sea

Hudson Bay

Asia

Bering Sea

North Sea

Europe

North America Japan Sea

Black Sea

Caspian Sea

North Atlantic Ocean

North Pacific Ocean

Mediterranean Sea

Yellow Sea

Persian Gulf

Gulf of Mexico Red Sea

South China Sea

Caribbean Sea

Africa

Arabian Sea

Equator South America

Indian Ocean

Coral Sea

Australia

South Pacific Ocean

South Atlantic Ocean

Indian Ocean

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Southern Ocean

Southern Ocean

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Arctic Ocean

Arctic Ocean

Baltic Sea

Hudson Bay

Asia

Bering Sea

North Sea

Europe

North America Japan Sea

Black Sea

Caspian Sea

North Atlantic Ocean

North Pacific Ocean

Mediterranean Sea

Yellow Sea

Persian Gulf

Gulf of Mexico Red Sea

South China Sea

Caribbean Sea

Africa

Arabian Sea

Equator South America

Indian Ocean

Coral Sea

Australia

South Pacific Ocean

South Atlantic Ocean

Indian Ocean

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Southern Ocean

Southern Ocean

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Island

Continental Coastline

Coral Reef

Continental Shelf Continental Slope

Atoll

Deep Ocean Basin Underwater Volcano

Trench

Mid-ocean ridge

Lava Chamber

Glossary adaptation (ad-ap-TAY-shuhn) — a change that a living thing goes through so it fits its environment. atolls (A-tols) — a chain of coral islands that forms a ring around a lagoon Antarctic Ocean (ant-ARK-tik OH-shuhn) — the ocean that surrounds Antarctica, also called the Southern Ocean Arctic Ocean (ARK-tik OH-shuhn) — the body of water located around the North Pole equator (i-KWAY-tur) — an imaginary line around the middle of the Earth, halfway between the North and South poles chlorofluorocarbons (KLOR oh FLOR oh KAR buhnz) — chemicals that damage the ozone layer and contribute to global warming continental (KON-tuh-nuhnt-uhl) — of a continent, associated with a continent 30

coral reef (KOR-uhl reef) — structures produced by living organisms, found in shallow, tropical marine waters export (EK-sport) — to send products to another country to be sold there geological (jee-ol-uh LOJ ik uhl) — relating to geology; the study of Earth hemisphere (HEM-uhss-fihr) — one half of a sphere, one half of the Earth hydrothermal (hye-droh-thur-muhl) — hot, ocean water generally created by underwater vents immense (i-MENSS) — huge, or enormous industry (IN-duh-stree) — a single branch of business or trade petroleum (puh-TROH-lee-uhm) — a thick, oily liquid found below the Earth’s surface used to make gasoline phytoplankton (FI-toh-plangk-tuhn) — microscopic ocean life that is the basis for the oceans’ food chain tsunami (tsoo-NAH-mee) — a large, destructive wave caused by an underwater earthquake, volcano, or landslide

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Island

Continental Coastline

Coral Reef

Continental Shelf Continental Slope

Atoll

Deep Ocean Basin Underwater Volcano

Trench

Mid-ocean ridge

Lava Chamber

Glossary adaptation (ad-ap-TAY-shuhn) — a change that a living thing goes through so it fits its environment. atolls (A-tols) — a chain of coral islands that forms a ring around a lagoon Antarctic Ocean (ant-ARK-tik OH-shuhn) — the ocean that surrounds Antarctica, also called the Southern Ocean Arctic Ocean (ARK-tik OH-shuhn) — the body of water located around the North Pole equator (i-KWAY-tur) — an imaginary line around the middle of the Earth, halfway between the North and South poles chlorofluorocarbons (KLOR oh FLOR oh KAR buhnz) — chemicals that damage the ozone layer and contribute to global warming continental (KON-tuh-nuhnt-uhl) — of a continent, associated with a continent 30

coral reef (KOR-uhl reef) — structures produced by living organisms, found in shallow, tropical marine waters export (EK-sport) — to send products to another country to be sold there geological (jee-ol-uh LOJ ik uhl) — relating to geology; the study of Earth hemisphere (HEM-uhss-fihr) — one half of a sphere, one half of the Earth hydrothermal (hye-droh-thur-muhl) — hot, ocean water generally created by underwater vents immense (i-MENSS) — huge, or enormous industry (IN-duh-stree) — a single branch of business or trade petroleum (puh-TROH-lee-uhm) — a thick, oily liquid found below the Earth’s surface used to make gasoline phytoplankton (FI-toh-plangk-tuhn) — microscopic ocean life that is the basis for the oceans’ food chain tsunami (tsoo-NAH-mee) — a large, destructive wave caused by an underwater earthquake, volcano, or landslide

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Index Antarctic Ocean 16, 17 Arctic Ocean 4, 11, 18, 19 Atlantic Ocean 4, 6, 7, 8, 29 atolls 14, 31 Caribbean Sea 7, 29 continental shelf 18, 22, 30 continental slope 22 coral reef 12, 13, 31 equator 6, 8, 10, 12, 16 Great Barrier Reef 12, 13 hurricanes 6, 21

iceberg 6, 11, 17 marine mammals 24, 25 North America 6, 7, 10, 18, 28 animals 5, 17, 19, 24, 25, 26 plants 5, 22, 24 Pacific Ocean 4, 10, 11, 12, 21 phytoplankton 19, 27 ring of fire 11 South America 8, 9, 12 tsunami 21

Further Reading Baker, Lucy. Life in the Oceans, Animals, People, Plants. Scholastic, 2005. Royston, Angela. My World of Geography, Oceans. Heinemann, 2005. Green, Emily. Oceans. Childrens Press, 2007.

Websites to Visit seawifs.gsfc.nasa.gov/ www.yoto98.noaa.gov www.oceanconservancy.org

About the Author Sandy Sepehri lives with her husband, Shahram, and their three children in Florida. She has a bachelor’s degree and writes freelance articles and children’s stories. She has also written a number of fiction and nonfiction books.

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