Blue whale saving giants of the ocean

Words: 301-400

Skills: Compare and Contrast Main / Central Idea Summary

Grades: 3rd 4th 5th

Topics: Science

Genres: Informational

Lexile Range: 740L - 1050L

Lexile Measure: 790L

CCSS: Reading: Informational Text and Science and Technical Subjects

Themes:

Blue Whales: Saving the Giants of the Ocean


Students will read a passage about blue whales and threats they face in their ocean environment. They will then answer questions about facts, comparing and contrasting, central ideas, and themes.

Reading Comprehension Passage

Blue Whales: Saving the Giants of the Ocean

Blue whales are the largest animals on Earth. They are also the largest animals known to have ever existed. This means that they are bigger than the dinosaurs that lived millions of years ago. Blue whales weigh as much as 33 elephants (200 tons) and can be up to 100 feet long. A baby blue whale is called a calf. A blue whale calf drinks over 100 gallons of milk every day.

Blue whales can live as long as humans. They can live to be 80 to 90 years old.

Blue whales eat mostly small shrimplike creatures called krill. Because blue whales are so big they need to eat lots of krill. They eat about four tons of krill a day. That is like eating 32,000 hamburgers a day. Blue whales spend their summers in polar waters eating large amounts of krill. Then they migrate thousands of miles to tropical and subtropical waters to spend the winter.

Blue whales live alone or in pairs. They are not like other types of whales that live in groups known as pods. Blue whales make a variety of sounds underwater. Scientists believe they make these sounds to communicate with each other. They also believe some of these sounds act like sonar. The sounds help the whales map their ocean environment. Some of the sounds they make can be heard for hundreds of miles underwater.

The biggest threat to blue whales is humans. Blue whales are hunted for their whale oil. Blue whales almost became extinct during the early part of the 20th century. This means they would have disappeared from the Earth forever. In 1966, the International Whaling Commission banned blue whale hunting. But some countries ignore this ban and continue to hunt blue whales.

Blue whales also face other threats from humans in their ocean environment. Ships sometimes strike whales and injure them. Ships also produce ocean noise that makes it hard for whales to communicate. Ocean pollution and fishing are other dangers facing blue whales. They sometimes become tangled and trapped in fishing nets.

Blue whales are an endangered species. Endangered species are animals that are in danger of disappearing forever. Only 10,000 to 25,000 blue whales remain in the world’s oceans. It is important to protect blue whales because they play a key role in the ocean’s food chain.

Passage Only

Reading Comprehension Questions

1. List three facts about blue whales.



2. What is one characteristic that makes blue whales different than other types of whales?



3. Why do blue whales make sounds?



4. Why are humans the biggest threat to blue whales?



Vocabulary List

Vocabulary List

Each of the vocabulary words below are used in the reading passage. As you read the passage, pay attention to context clues that suggest the word’s meaning.

  1. polar
  2. migrate
  3. sonar
  4. banned
  5. environment

Context Clues

Context Clues

Using context clues from the sentences in the passage, underline the correct meaning of the word in boldface.

1) “Blue whales spend their summers in polar waters”

a. near the North or South Pole      b. coastal; shoreline     c. Pacific     d. deep; below the surface

2) “Then they migrate thousands of miles to tropical and subtropical waters”

a. explore; discover     b. avoid or go away from     c. like; enjoy     d. travel or move

3) “They also believe some of these sounds act like sonar

a. sound system for location      b. magnets or attractions     c. mirrors; reflections     d. sponges

4) “the International Whaling Commission banned blue whale hunting”

a. researched; studied     b. planned; outlined     c. prohibited or outlawed     d. encouraged; aided

5) “Blue whales also face other threats from humans in their ocean environment

a. mountains; hills     b. habitat or setting     c. currents or waves     d. beach; coast