Lesson 1: Just Another Day in the HoodAn Introduction to Symbiotic Relationships in the

Coral Reef Ecosystem

Kira Withy-AllenTeacher/Research Assistant

University of California, Santa BarbaraResearch Experience for Teachers

National Science Foundation

Background: Moorea LTER UnitCan you outsmart a scientist?• In the following lessons, you will be the brains

behind research done by scientists at the University of California, Santa Barbara.

• You will decide what their hypotheses should be and how they should set up their experiments.

• The scientists you are up against have spent many years studying the ecology of organisms, so be prepared for some big competition!

• Since there are no coral reefs in California, the scientists must travel to the island of Moorea, French Polynesia to conduct their research.

Do you have a coral reef near you?

Moorea is a tropical island in French Polynesia. It is near the Northwestern end of Tahiti.

The island of MOOREA

UC Berkeley Gump Research Station: Where scientists live and conduct research while in Moorea.

Scientists in Moorea are studying a barrier reef. This is a reef that is parallel to the shore and usually separated from land by a lagoon.

UC Berkeley Gump Research Station Moorea, French Polynesia

Research Boats

Dorms

Repair ShopWet and Dry Laboratories

Library

Tahitian hut (“Fare”)

The scientists we will encounter in the next two lessons have been studying different

organisms that participate in “symbiosis.”

Symbiosis: A close relationship between two organisms. Many symbiotic organisms share a living space.

Symbiont: Usually the smaller

organism in a symbiotic relationship. Example: Algae called zooxanthellae that often live inside the tissue of a coral.

Host: Usually the larger organism in a symbiotic relationship.

Example: A coral polyp.

In this case, the Symbiont lives inside of the tissues of the Host.

There are three main trends observed with organisms that participate in symbiotic relationships.

• Mutualism: A relationship between two organisms (host and symbiont) in which both benefit from the interaction.

• Parasitism: A relationship between two organisms in which one organism benefits at the other organism's expense.

• Commensalism: A relationship between two organisms in which the host neither benefits nor is hurt by the relationship.

Host

Host

Host

Symbiont

Symbiont

Symbiont

A Symbiotic Relationship:Coral and Zooxanthellae

For the rest of this lesson, we are going to learn what life processes corals and zooxanthellae must do in order to survive.

Assignment: You are expected to decide the main reason why coral and zooxanthellae might be found living together on the reef. On your paper, jot down notes or draw pictures that may help you decide.

What do plants and algae need to survive?

• Discuss what you think plants and algae in the ocean or on land need to survive.

• Do ocean and land plants need the same things? What is the same? What is different?

• Brainstorm and write down your ideas.

Ocean Algae: Zooxanthellae Land Plant: Rainforest Tree

Optional Activity: DEBATEQuestion: Are plants and algae the same thing?

Divide students in the classroom into two groups. One group supports the notion that plants and algae are the same thing and the other group will challenge this by mentioning any differences between the two.

Stumped? Scientists have spent a lot of time debating this issue.Some Similarities: • Both are producers that carry out a process called Photosynthesis.• Both have chlorophyll and chloroplasts.• Both can be found on land and in the aquatic environment.Some Differences: • Protists (most algae) and Monera (Blue-green algae) come from

different kingdoms than plants (Plantae) . Note: Chlorophycota is commonly slumped with Plantae.

• Algae and plants don’t share a similar structure (i.e. roots).

Plants and algae, both on land and in water, survive using similar basic resources. However, they take in the resources in different ways and from different materials depending on the environment.

All plants need:

1. An Energy Source: Sunlight or artificial light.

Plants and algae have a special green pigment called chlorophyll that allows them

to attract and absorb sunlight rays.

Inputs: Resources organisms use to function.

All plants need:

1. An Energy Source: Sunlight or artificial light.

H2O

2. Water is very important for organisms to function correctly.

All plants need:

1. An Energy Source: Sunlight or artificial light.

3. Carbon Dioxide gas is absorbed from the water.

CO2H2O

2. Water is very important for organisms to function correctly.

All plants need:

1. An Energy Source: Sunlight or artificial light.

4. A food source: Nutrients from soil, decaying organisms, or the surrounding environment.

3. Carbon Dioxide gas is absorbed from the water.CO2

H2O

2. Water is very important for organisms to function correctly.

What happens to these resources once they are taken up by a plant?

Assignment: Brainstorm and discuss at least 5 reasons why plants are important on Earth and use these reasons to answer the question above.

Hint: Some questions you may want to ask yourself include: Do plants benefit you in any way? Where do you find plants? What are they used for? Do we NEED plants?

Why are plants and algae important?Animals (including us) use the outputs of plants as

food and for additional resources.INPUTS OUTPUTS

CO2

C6H12O6Glucose, a simple sugar molecule that stores energy.

Outputs: What an organism produces or releases after using the inputs.

INPUTS OUTPUTS

CO2

C6H12O61. Glucose, a simple sugar molecule that stores energy.

O22. A gas called Oxygen is released. Does that word sound familiar?

H2O

INPUTS OUTPUTS

CO2

C6H12O61. Glucose, a simple sugar molecule that stores energy.

O22. A gas called Oxygen is released. Does that word sound familiar?

H2O

3. WASTE

INPUTS OUTPUTS

CO2

C6H12O61. Glucose, a simple sugar molecule that stores energy.

O22. A gas called Oxygen is released. Does that word sound familiar?

H2O

3. WASTE

4. Water is usually an input and output.

Does anyone know what this process that plants and algae perform is called?

PHOTOSYNTHESIS! Can you say it?Another crazy scientific word! At least that was easier to pronounce than zooxanthellae, right? But now I forgot what photosynthesis is! Can you define it?

Photosynthesis: A chemical process in which green plants combine carbon dioxide and water in the presence of light energy and chlorophyll to produce carbohydrates and oxygen.

Sunlight+ Carbon Dioxide+ Water + Nutrients Glucose+ Oxygen+ Waste+ Water

That’s what you SAID, I’m sure of it!

Test yourself: Do you know the symbols for some of the molecules, such as Carbon Dioxide?

This whole process of photosynthesis takes place in a specialized organelle, which is found inside plant and algal cells. It is called a…

CHLOROPLAST: A specialized organelle inside a plant or algal cell where photosynthesis takes place.

Note that the chloroplast (light green) has the chlorophyll pigment (dark green) inside of it to attract the sunlight so the process of photosynthesis has energy to begin.

Do zooxanthellae perform photosynthesis?

• You bet!

• Scientists believe that zooxanthellae and other phytoplankton (often microscopic plants) in the ocean produce AT LEAST HALF of our Earth’s OXYGEN via photosynthesis.

• Since organisms that perform photosynthesis can

make their own food, they are called producers.Supplemental article: “Source of Half Earth's Oxygen Gets Little Credit”http://news.nationalgeographic.com/news/2004/06/0607_040607_phytoplankton.html

What does all of this photosynthesis stuff have to do with CORAL?

POP QUIZ

aaaggghh…

1. Are corals plants?

No! Coral is an animal.

2. Does coral perform photosynthesis?

No! Animal cells do not have chloroplasts.

3. What is the process that animals perform to survive called?

RESPIRATION

INPUTS

C6H12O6

1. An energy source: Glucose, a simple sugar molecule that stores energy made through photosynthesis.

Coral

Respiration: A chemical process that releases the energy stored in food and forms new products.

INPUTS

C6H12O6

1. An energy source: Glucose, a simple sugar molecule that stores energy made through photosynthesis.

H2O

2. Water is very important for organisms to function correctly.

Respiration

INPUTS

C6H12O6

1. An energy source: Glucose, a simple sugar molecule that stores energy made through photosynthesis.

O2

3. Oxygen gas is either absorbed from the water by tissues (coral) or gills (fish), or taken in through the lungs from the air (whales).

H2O

2. Water is very important for organisms to function correctly.

Respiration

Do you recognize any of the INPUTS for respiration?

You should, they are the OUTPUTS for photosynthesis!

BOB is shocked.

INPUTS OUTPUTS

C6H12O6

Glucose

O2

Oxygen gas H2OWater

1. The energy in food (such as glucose) is transferred to the animal to run its bodily processes, and is then released as heat. Energy does not get used up, it just transfers from one object to another.

HEAT

What are the outputs for respiration?

INPUTS OUTPUTS

CO2

C6H12O6

Glucose

O2

Oxygen gas H2OWater

1. The energy in food (such as glucose) is transferred to the animal to run its bodily processes, and is then released as heat. Energy does not get used up, it just transfers from one object to another.

HEAT

2. Gas: Carbon Dioxide gas is released into the water.

Respiration

INPUTS OUTPUTS

CO2

C6H12O6

Glucose

O2

Oxygen gas H2O

3. WASTE/NUTRIENTS

Water

1. The energy in food (such as glucose) is transferred to the animal to run its bodily processes, and is then released as heat. Energy does not get used up, it just transfers from one object to another.

HEAT

2. Gas: Carbon Dioxide gas is released into the water.

Respiration

INPUTS OUTPUTS

CO2

C6H12O6

Glucose

O2

Oxygen gas H2O

3. WASTE/NUTRIENTS

4. Water is usually an input and output.

1. The energy in food (such as glucose) is transferred to the animal to run its bodily processes, and is then released as heat. Energy does not get used up, it just transfers from one object to another.

HEAT

2. Gas: Carbon Dioxide gas is released into the water.

Respiration

Consumer vs. ProducerOrganisms that undergo respiration are often called Consumers because they cannot perform photosynthesis to make their own food, so they must consume it from something else.

Exception: Producers Do you remember what producers are?Producers make their own food by performing photosynthesis (i.e. plants), but in order to gain energy to use for their processes, they must also do respiration and use small amounts of their own food (glucose) energy that is stored.

Do you recognize any of the OUTPUTS from respiration?

You should, some are the INPUTS for photosynthesis!

Congratulations, BOB is shocked again!

Remember this Assignment?

A Symbiotic Relationship:Coral and Zooxanthellae

Assignment: You are expected to decide the main reason why coral and zooxanthellae might be found living together on the reef. On your paper, jot down notes or draw pictures that may help you decide.

Take a few minutes now to finish processing your thoughts. Have you thought of any ways that zooxanthellae and coral could help each other out?

INPUTS OUTPUTS

CO2

C6H12O6

O2

H2OWASTE

REVIEW: PHOTOSYNTHESIS

or

INPUTS OUTPUTS

CO2

C6H12O6

O2

H2O

WASTE/NUTRIENTS

HEAT

REVIEW: RESPIRATION

or

PHOTOSYNTHESIS and RESPIRATION are opposite processes.

The INPUTS for photosynthesis are the OUTPUTS from respiration!

PHOTOSYNTHESIS INPUTS PHOTOSYNTHESIS OUTPUTS

Sunlight+ Carbon Dioxide+ Water + Nutrients* Glucose+ Oxygen+ Waste (nutrients)*+ Water

The OUTPUTS from photosynthesis are the INPUTS for respiration!

Okay, we need to stop shocking BOB before his hands become permanently stuck to his face.

RESPIRATION INPUTS RESPIRATION OUTPUTSGlucose+ Oxygen+ Nutrients+ Water Heat+ Carbon Dioxide+ Water + Nutrients* (waste)

*Note: Matter is recycled! Nutrients such as Nitrogen can come out as waste from a consumer is “fixed” by bacteria so that it can be taken up again as fertilizer by the producer.

Sunlight Glucose Heat

Carbon Dioxide Oxygen

Water Waste (nutrients)

Nutrients Water

What does this mean for organisms that live symbiotically and can perform both photosynthesis (zooxanthellae) and

respiration (zooxanthellae and coral)?

Energy transfer: In Photosynthesis and Respiration, energy changes forms but does not get used up. It begins as light energy, then is converted into chemical energy during photosynthesis (energy is stored in food), and is released into the atmosphere as heat when respiration is complete.

Matter: Matter is anything with mass. All matter is recycled in the system.

Which type of symbiotic relationship do coral and zooxanthellae exhibit?

MUTUALISM! They both benefit from the interaction in the following ways:

CORALS receive energy from zooxanthellae, which is stored in the glucose that the zooxanthellae produce during photosynthesis. The rest of their energy (and nutrients) is obtained from their food, zooplankton, which they catch with their stinging tentacles. Corals need lots of energy to reproduce new individuals that can add to the size of a reef.

ZOOXANTHELLAE receive protection from a coral’s hard skeleton and stinging cells. Zooxanthellae also use some of coral waste as nutrients.

More interesting information about the relationship: Reef-building corals get their coloration from the zooxanthellae in their tissues, so it is difficult to identify coral species based on their coloration. When corals are stressed, they release their zooxanthellae and become all white (what we know as coral bleaching).

In the next two lessons we will learn more about symbiotic relationships by looking at actual research being conducting by scientists on coral reef organisms.

End of Lesson

Vocabulary Check• Zooxanthella (zooxanthellae = plural): A single-celled algae (dinoflagellate) that

can often be found living within the tissue of certain Cnidarians, especially reef-building corals.

• Hypothesis (Hypotheses = plural): An educated prediction.• Ecology: The study of how organisms interact with each other and their physical

environment.• Barrier Reef: A reef that is parallel to the shore and usually separated from land by a

lagoon.• Symbiosis: A close relationship between two organisms. Many symbiotic organisms

share a living space.• Symbiont: Usually the smaller organism in a symbiotic relationship. • Host: Usually the larger organism in a symbiotic relationship.• Mutualism: A relationship between two organisms (host and symbiont) in which both

benefit from the interaction.• Parasitism: A relationship between two organisms in which one organism benefits at

the other organism's expense. • Commensalism: A relationship between two organisms in which the host neither

benefits nor is hurt by the relationship.• Producer: An organism capable of making its own food.• Photosynthesis: Process of using energy in sunlight to convert water and carbon

dioxide into carbohydrates (sugar, energy) and oxygen.• Chlorophyll: A specialized pigment found in producers that allows them to attract

and absorb sunlight rays.• Chloroplast: The organelle where photosynthesis takes place in a plant or algal cell.• Inputs: Resources organisms use to function.• Matter: Anything with mass.• Energy: Anything that can be converted into and measured as heat.

Work CitedTextVocabulary and teaching techniques throughout this unit were adapted from:1. Pottenger, F.M., Young, D.B., and Klemm, B.E. Matter and Energy in

the Biosphere: FAST (Foundational Approaches in Science Teaching). Curriculum Research and Development Group, University of Hawaii at Manoa,1978.

Photos1. Col, Jeananda. Enchanted Learning.

http://www.EnchantedLearning.com 1996 (slide 22).2. Mattia, Christopher. University of Maryland Center for Environmental

Science. 1997. www.cbl.umces.edu. 3. Utah State Office of Education, http://www.usoe.k12.ut.us/ (slide 12).4. Santos, Scott R. State University of New York at Buffalo.

www.coral.noaa.gov (Slides 9, 23, 36, 39).5. Stewart, Hannah. Post-Doctorate Fellow. University of California,

Santa Barbara (Slides 3, 4, 5, 25, 26, 27, 29, 30, 31, 32, 37, 39). 6. Withy-Allen, Kira. University of California, Santa Barbara and

University Laboratory School, University of Hawaii at Manoa (Slides 1, 9, 16, 24, 41).