Name: _______________________________

Invasive Species: Zebra & Quagga Mussels

Can anything stop these silent invaders?

The Zebra Mussel, Dreissena polymorpha is a small, striped bivalve about the size of a dime that is native to the Russian Caspian, Black, Aral and Azov seas. The Zebra mussel was first observed in North America in 1988 in Lake St. Clair followed by its cousin, the Quagga Mussel. They quickly infested the Great Lakes and used the Mississippi and St. Lawrence waterways to travel across the country. They are more than just a nuisance and represent a devastating impact on native species, a billion dollar fishing industry and human health. Here's how.

In this YouTube video, "Silent Invaders" you will observe a number of interesting characteristics about this creature. You will also discover how certain organisms can have a disruptive or damaging impact on a local ecosystem and man's attempts to stop them. Please answer the questions below in the space provided and develop your answers carefully.

Key Termsecosystem diatom food web phytoplanktonzooplankton diporeia invasive byssal threadssubstrate bivalve veliger stage larvaeGreat Lakes parasite bio control thermocline

Video Assessment Worksheet

1) Name six (6) characteristics of the Zebra Mussel.1. 2.3. 4.5. 6.

2) What is an "invasive species" and give three (3) examples.

a. b. c.

3) What is an ecosystem?

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4) How did the Zebra Mussel first appear in the United States?

5) Describe four possible ways to get rid of this nuisance.a.b.c.d.

6) Quagga mussels are competing with other organisms for food. What do they eat?

7) How would you define a "food web"?

8) 20% of the world's fresh water is found in the Great Lakes. True/False?

9) Most mussels have bysaal threads. What purpose do they serve?

10) Mussel Anatomy: Use the attached diagram and label each organ found in the zebra mussel.

11. Diatoms are favorite foods of the Zebra and Quagga mussel. What exactly are they?

12. Quagga mussels are quite tasty and many organisms consider them a suitable food source. Give two reasons why this statement is false.

1.2.

13. There are two (2) types of plankton which is also a valuable food source. Name the two types of plankton.1.2.

14. Describe how the types of plankton are different.

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15. An infestation of zebra or quagga mussels can cause a change in the water temperature of a given body of water. Explain how this can happen.

16. Biological Control may be the only answer to controlling this mussel infestation. What do we mean by this term and give two possible examples.

1.2.

17. Explain how zebra and quagga mussels pose a threat to other mussel species.

18. Fortunately, zebra mussel larvae are easy to see and natural predators like the spiny sand flea can eat them before they mature. True/False?

19. How can recreational boaters and fisherman help prevent the spread of zebra mussels?

Bonus Question: The Quagga mussel is named after an extinct species of animal originally from Africa. Can you guess which one?

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Critical Thinking Essay

The Zebra and Quagga mussels can quickly infest a body water and cause disruption to the ecosystem. They are voracious feeders and can multiply quickly. Mussels can produce over 4 million eggs in a life time which means they have the ability to overwhelm a freshwater habitat with alarming speed. These creatures are native to the Caspian and Black Seas and are usually found in freshwater lakes, ponds and streams. They have quickly populated much of the Eastern and Midwestern United States and have been found as far west as California. They have no know predators here in the United States.

Students, your assignment is to prepare an insightful and carefully researched essay on the impact of the Zebra/Quagga mussel on the freshwater ecosystem. Your two part essay should include: (1) a thorough physical description of this bivalve as an invasive species; and (2) a description of the Great Lakes Food Web and ecosystem including those organisms that have been harmed by its presence. Students should keep in mind that the recreational fishing industry in the Great Lakes region generates billions of dollars annually. Successful essays will include carefully worded, supportive arguments and factual data. Your teacher will provide you with the guidelines on length, font size, assignment deadline etc.

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Invasive Species: Zebra mussels

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Invasive Species: The Zebra Mussel

Lake Michigan Food Web

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Name: _________________________________

Mussel Anatomy DiagramDreissena polymorpha

stomach

Organ Bank

1. stomach 9. palps2. digestive gland 10. mantle3. inhalent siphon 11. gills4. exhalent siphon 12. intestine5. heart 13. anus6. mouth 14. kidney7. foot 15. anterior abductor muscle8. shell 16. posterior abductor muscle

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Name: _________________________________

Diatom Drawing ActivityIt's hard to believe they are real!

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Invasive SpeciesZebra & Quagga Mussels

ANSWER KEY Teachers, this lesson packet is based on the YouTube video "Silent Invaders" Episode 2 produced by Wildlifeforever videos. The duration is 21.30 min. Students will be able to practice their note taking research skills prior to completing the video assessment worksheet. It will be very helpful if students have internet access either through class computers, iPads or PEDs.

It is highly recommended that you introduce these key terms to your students prior to watching the video. You may wish to further expand on some of these concepts such as ecosystem, invasive species, bio control and others in future classes. This lesson packet can easily consume 3-5 class periods depending on the depth and duration of class discussions, student ability etc.

Key Termsecosystem diatom food web phytoplanktonzooplankton diporeia invasive byssal threadssubstrate bivalve veliger stage larvaeGreat Lakes parasite bio control thermocline

Video Assessment Worksheet

1) Name six (6) characteristics of the Zebra Mussel. responses may vary1. filter feeder 2. came from Russia3. size of a dime 3-4 cm 4. can attach to any surface5. lives in cool water 6. eats diatoms

2) What is an "invasive species" and give three (3) examples.A non native species that has a harmful impact on a given ecosystem, or other native species.a. subterranean termite b. cane toad c. fire ant

3) What is an ecosystem? The relationship between living (biotic) and non living (abiotic) components in a given location.

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4) How did the Zebra Mussel first appear in the United States? Transported in the ballast water of a container ship from Russia/Europe

5) Describe four possible ways to get rid of this nuisance.a. physical removalb. chemical poisonsc. introducing a natural predator (bio control)d. removing its food source

6) Quagga mussels are competing with other organisms for food. What do they eat? They eat diatoms which are eaten by zooplanton

7) How would you define a "food web"? It shows the inter relationship between species in an ecosystem. Several food chains interacting with each other.

8) 20% of the world's fresh water is found in the Great Lakes. True/False?

9) Most mussels have bysaal threads. What purpose do they serve?They are used to anchor the mussel to a given substrate

10) Mussel Anatomy: Use the attached diagram and label each organ found in the zebra mussel. See attached key

11. Diatoms are favorite foods of the Zebra and Quagga mussel. What exactly are they? Diatoms are single celled algae with shells made of silica. There are many of different shapes and sizes and they are closely related to plankton. Their dried shells have many commercial uses.

12. Quagga mussels are quite tasty and many organisms consider them a suitable food source. Give two reasons why this statement is false.

1. they have little nutritional value2. they are hard to digest

13. There are two (2) types of plankton which is also a valuable food source. Name the two types of plankton.1. zooplankton2. phytoplankton

14. Describe how the types of plankton are different. Zooplankton is actually an animal while phytoplankton is a plant and therefore photosynthetic. Diatoms

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and algae are forms of phytoplankton and tiny fish larvae and crustaceans are forms of zooplankton. Zooplankton eat phytoplankton.

15. An infestation of zebra or quagga mussels can cause a change in the water temperature of a given body of water. Explain how this can happen. They are both filter feeders and consume huge amounts of algae. The lake water becomes much clearer allowing greater penetration of sunlight which warms the water at deeper levels. Warm water can kill some organisms and create plant infestation and pond eutrophication in others.

16. Biological Control may be the only answer to controlling this mussel infestation. What do we mean by this term and give two possible examples.

1. introducing a natural predator2. introducing a living bacteria or parasite that kills the mussel host

17. Explain how zebra and quagga mussels pose a threat to other mussel species.Bysaal threads prevent native mussels from opening their shells, restrict intake of nutrients

18. Fortunately, zebra mussel larvae are easy to see and natural predators like the spiny sand flea can eat them before they mature. True/False? Mussel larvae are invisible!

19. How can recreational boaters and fisherman help prevent the spread of zebra mussels? Dump lake water from bait wells, engines, bilge pumps and coolers before using the boat, kayak or canoe again.

Bonus Question: The Quagga mussel is named after an extinct species of animal originally from Africa. Can you guess which one? The Zebra (Teachers, this may seem obvious given its relationship to the Zebra mussel but students are often distracted by the term "extinct" and the fact that the question refers specifically to the Quagga mussel.

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Mussel Anatomy DiagramDreissena polymorpha

ANSWER KEY

stomach heart digestive gland kidney posterior abductor anterior abductor muscle

muscle anus

exhalent siphonmouthpalps inhalent siphon intestine foot mantle shell gills

Organ Bank

1. stomach 9. palps2. digestive gland 10. mantle3. inhalent siphon 11. gills4. exhalent siphon 12. intestine5. heart 13. anus6. mouth 14. kidney7. foot 15. anterior abductor muscle

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8. shell 16. posterior abductor muscle

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