Sharks: The Ecosystem Needs Them!

Sharks: The Ecosystem Needs Them!

Sharks: The Ecosystem Needs Them!

When people hear the word shark, panic often follows. Sharks have a bad reputation. This is partly because they have a lot of sharp teeth. They even look a little scary. Some people fear the worst when they go into the ocean for a swim. Sharks have been killed because some people fear the worst. This has happened even when the shark is unprovoked. But sharks are not really interested in hurting people. They are just doing what they were meant to do. Sharks are extremely important to the health of the underwater ocean ecosystem of plants, animals, and fish. Without sharks, oceans would become unbalanced and unhealthy.

Multiple Choice

What is the topic of this article?

• Sharks

• Oceans

• Danger

• Ecosystems

Multiple Choice

How do sharks benefit the ocean?

• they keep it clean

• they keep it balanced and healthy

• they prevent pollution

• they eat human predators

Sharks: The Ecosystem Needs Them!

Have you ever caught a cold or the flu from someone? All of us have had this happen. Sickness can quickly be passed from person to person. The same thing can happen under water. Diseases and illness can be passed from one fish to another. Unlike us, fish do not have doctors to go to for medicine. Diseases can spread through their populations and cause many fish to die. When fish get sick, they tend to move slower than healthy fish. Sharks prefer to eat food that is easy to catch. Catching sick fish can be done without much effort. They become easy prey, or food. Scientists have found that by removing the sick and the weak fish in an ecosystem, sharks prevent disease and outbreaks that could be devastating.

Multiple Choice

What is another word for prey?

• hunter

• fish

• food

• ocean creature

Multiple Choice

Cause: Sharks eat sick and weak fish. Which is the Effect?

• they spread the diseases more

• they make more room for healthy fish

• they prevent disease and outbreaks

• they get sick also

Sharks: The Ecosystem Needs Them!

An ecosystem can easily become over populated. This means that there are too many fish in one area. Some fish can reproduce, or have babies, very quickly. All living organisms need food to eat so that they can stay alive. If there are too many fish, then some won't have enough food to eat. This will cause them to die.

Multiple Choice

As used in the text, what does reproduce mean?

• to locate more fish

• to decrease population

• to copy something

• to have babies

Multiple Select

Cause: Too many fish in one area. Choose 2 Effects.

• Mr. Meiser won't swim

• some won't have enough food to eat

• some of them will die

• the sharks won't eat

Sharks: The Ecosystem Needs Them!

Whatever organism that these fish eat will eventually be gone from that ecosystem because they will all have been eaten. Sharks help keep the number of fish in an ecosystem balanced. The number of fish won't grow too large in one area as the shark eats them. Scientific studies show that sharks keep the food chain in balance all the way down to tuna and coral reefs.

Multiple Choice

According to this paragraph, why are shark important to their ecosystem?

• Sharks eat only sick fish.

• Sharks help keep baby fish alive in an ecosystem.

• Sharks help keep the number of fish in an ecosystem balanced.

Sharks: The Ecosystem Needs Them!

Scientists in Hawaii have found that tiger sharks have a positive impact on the health of sea grass beds. Turtles, which are the tiger sharks' prey, graze on sea grass. Without tiger sharks, the turtles spent all their time grazing on the best quality, most nutritious sea grass. Sea turtles like it so much that if they got a chance, they would stay all day eating in one area until no more was left. This can be harmful because other fish and sea life rely on that sea grass for food and shelter. Without the sea grass protection, larger fish would be able to catch them more easily. As sharks swim around and patrol the area, the sea turtles are more likely to eat quickly and move on to another place.

Multiple Choice

Sharks have a positive impact on ________________.

• sea grass beds

• sea turtles

• larger fish

• choral reefs

Sharks: The Ecosystem Needs Them!

Thanks to sharks, our oceans stay healthy and balanced. Because sharks eat a variety of fish and other sea life, no one population will become too large and out of control. This ensures that organisms living in the ocean have enough to eat. Sharks also protect fish populations from being wiped out by disease. Sharks will eat the sick fish so that diseases do not spread as easily. And finally, they keep sea turtles and other marine life from eating all of one food source. Sea turtles are prevented from eating all of the grass that other fish rely on for safety and food. We should all be thankful to sharks for helping to keep our ocean ecosystems balanced and healthy.

Multiple Choice

Is the author's attitude towards sharks positive or negative?

• positive

• negative

Multiple Choice

What is the author's main point in this article?

• Sharks keep our ocean ecosystem balanced and healthy.

• Sharks are unhealthy for the ocean ecosystem.

• Sharks are scary creatures with sharp teeth.

• Sharks prevent sea turtles from eating too much sea grass.