Diving into STEM with Oceanic Research Group … 14 STUDENT...Tridacna gigas, the giant clam, is usually blue, golden brown, yellow, or green. This clam really is a giant, growing

Diving into STEM with Oceanic Research GroupElementary Unit: Focus on STEM with FishKiller Clams Lesson: Student Resources

Concepts: The Lifespan of Overfishing, Symbiotic Relationships, Solar Power

Overview: Jonathan goes to Micronesia to find giant clams! Tridacna clams are so big that people used to think they caught people. Jonathan wants to research to learn if the Tridacna clams are really dangerous.

Online Resources: Jonathan Bird’s Blue World webisode 14 Killer Clams (www.blueworldTV.com)

Elementary Unit - Killer Clams: Student Resources - Page 1Learn more at www.BlueWorldTV.com!

IntroductionThere have been many stories about Tridacna clams, or giant clams. Many of these stories describe how the clams are aggressive towards people and that they try to capture or hurt swimmers. Jonathan heard these myths and legends, and since he is a scientist, he does not assume that these stories are true. He is also very curious, so he wanted to research the clams to see firsthand if these big clams really are threatening to people. So, he investigated where these clams live and went to visit Micronesia. Jonathan first discovers that the Tridacna clams are very popular to eat, and many restaurants serve these clams for lunch and dinner.

Jonathan dives to see these Giant Clams in the water, and tests the hypothesis that these clams are treacherous. When Jonathan finally finds a clam, at the bottom of the Pacific Ocean, he performs a few tests to see what he can find.

He discovers that these Tridacna Clams are becoming scarce. The Tridacna clam takes many years to grow big, and many fishermen catch these clams to sell to the restaurants and fish markets. The clams cannot reproduce quickly, so they are disappearing. Today the Giant Clams are classified as “locally extinct” or “vulnerable”. So, as Jonathan discovers, the Tridacna clam is not dangerous to people but actually in danger.


Killer Clams Lesson: Student Resources Contents

Section Page Afterschool ClassroomScience Notebook Framework 3 X XBackground 4 X XEssential Vocabulary 5 X XExtended Vocabulary 6 X XVocabulary Bingo Game 7 XMap Location Activity 8 XConnection to Cultures 8 XPost-viewing Questions & Writing Prompts 9 X5W Questions Worksheet 9 XListening Dictation Exercise 10 X XActivity: The Economics of Overfishing Rules 11 XActivity: The Economics of Overfishing Data Table 12 X


Unit:______________________________ Investigation/Part_____________________________________

Idea:_____________________________________________________________________________________

(1) PLANNING THE INVESTIGATION:Focus Question Prediction (I think/predict that_________ because _______)Planning (What should be changed? What should be kept the same? How will differences be measured?)

(2) DATA ACQUISITION & ORGANIZATION:Data Collection Methods (How will students record data? Drawings, charts & tables, artifacts, graphs & organizers)Data obtained (What is the expected outcome of the observations?)Data display (Data re-organization, graphic organizers)

(3) MAKING MEANING:Discussion/analysis Conference: Science Talk

Claims & Evidence listing:

Claim Evidence(I claim that...) (I know this because...)

Conclusion (How do claims and evidence related to the big idea? Were predictions supported by the evi-dence?)

(4) REFLECTION & SELF-ASSESSMENT:Line of learning (What did you learn that was new?)Reflection/Self-reflection (At first thought...now I think...I still need help understanding)Next Step Strategies

SCIENCE NOTEBOOK FRAMEWORK


Tridacna gigas, the giant clam, is usually blue, golden brown, yellow, or green. This clam really is a giant, growing to 4 feet long and weighing over 500 pounds and it can live for more than one hundred years. Each side of the shell is made by the outer edge of the mantle. The shell is fused together at the dorsal surface and encloses the mantle cavity, the fleshy part of the giant clam. The giant clam has two siphons one to suck water in and the other to push water out. Tridacna can squirt a forceful jet of water out of its “excurrent” siphon by quickly opening and closing its shell. Perhaps one of the most unusual attributes of this clam is that its colorful skin hides a thick layer of zooxanthellae or algae. The zooxanthellae and the clam have a symbiotic relationship. The zooxanthellae make food for the clam using the energy from the sun. The algae feed off the clam’s waste. The water the clam sucks through its “incurrent” siphon brings the tiny algae oxygen and flushes away excess waste materials. Most of the giant clam’s nutrients come from the zooxanthellae living under its skin. The giant clam farms its zooxanthellae.

Since the giant clam can’t move, reproduction is done by spawning. Each Tridacna gigas produces sperm and eggs. Through a synchronization process each clam releases either sperm or egg into the water to complete the spawning process. The giant clams release their gametes into the water at the same time, in the hopes there will be enough gametes to fertilize each other. When this event happens, the water looks milky.

Tridacna has been historically misunderstood. Some scientific and technical manuals once claimed that the great mollusk had caused deaths. In those days the Tridacna was also known as the killer clam or man-eating clam. Older versions of the U.S. Navy Diving Manual gave detailed instructions for releasing oneself from the clams grasp by severing the adductor muscles used to close its shell. We know now that

the giant clam is neither aggressive nor dangerous; the shell’s closing action is actually a defensive response, it closes slowly and not tightly.

The International Union for Conservation of Nature and Natural Resources (IUCN) lists Tridacna as vulnerable because its numbers have been greatly reduced by extensive harvesting for food and aquarium trade.

Giant Tridacna clams on a reef in Kosrae, Micronesia.

Giant Tridacna clam, Raja Ampat, Indonesia.

Background

Directions: Find a picture or a synonym (similar word) for each of the Essential Vocabulary words. The first one is done for you. Use a dictionary, thesaurus, internet, or any other resource available to you.

CLAM - a marine bivalve mollusk that lives in sand or mud

SYMBIOSIS –

SOLAR –

FARM –

RAISE –

PLANKTON –

MYTH –

GIANT –

HARVEST -

OVER HARVESTED/ OVER-FISHED –

SIPHONS –

TISSUE –

REEF –

COLLAPSE -

MANTLE -

SUSTAINABILITY -

VULNERABLE -

ESSENTIAL VOCABULARY Killer Clams


EXTENDED VOCABULARY Killer Clams: Teacher Answer Key

Directions: Find a picture or a synonym (similar word) for each of the Extended Vocabulary words. Use a dic-tionary, thesaurus, Internet, or any other resource available to you.

SEARCH – RETRACT – SENSITIVE – RESPOND – SECRET – SHALLOW – SLURP – DEPLETE – CIRCULATE – DELICACY – MATURE – HUNT – SHADOW –DANGEROUS – SIEVE – SOAK – EXTRACT –

Idiomatic language: ALL THE WAY - totallyFIND OUT - research/discoverLOOK AROUND - look for/searchAT LAST - finally



Vocabulary Bingo: Killer Clams• Write one word from the list below in each of the 25 boxes in whatever sequence you desire. Do not repeat words, and do not leave any spaces blank.• The instructor will read definitions in sequence. Place the number of the definition in the box with the associated term. When you have five in a row, shout, “Bingo!”

a. CLAM b. SYMBIOSISc. SOLARd. FARMe. RAISEf. PLANKTON

m. REEFn. RETRACTo. SENSITIVEp. SECRET q. SHALLOWr. DEPLETE

s. CIRCULATEt. DELICACYu. MATUREv. SHADOWw. SIEVEx. SOAK y. OVER HARVESTED/OVER-FISHED

g. MYTH h. GIANT i. HARVESTj. EXTRACT k. SIPHONSl. TISSUE

Map Activity

FIND MICRONESIA ON THE MAP AND COLOR IT RED. FIND THE UNITED STATES AND COLOR IT YELLOW.

Elementary Unit - Killer Clams: Teacher Resources - Page 8Learn more at www.BlueWorldTV.com!

Connection To Cultures1. Does anyone have a story/myth/folk tale from their culture about a clam that they would like to share? 2. There is a Native American story called The Gossiping Clams. Has anyone heard of that story?


5 W Questions

1. Q: Where are Tridacna (giant) clams found?

2. Q: Why are Tridacna clams disappearing from the reefs?

3. Q: What does the Tridacna clam eat?

4. Q: When did the clam get to the weight of 100 pounds?

5. Q: Who gets hurt by the Killer Clams?

6. Q: How is the sun important to the Tridacna clam?

7. Q: How do the Giant clams eat?

Post Viewing Questions & Writing Prompts

1. What are the effects of overfishing?2. What happens when a large percentage of a fish species is removed from the ocean? 3. Where does your family get the fish you eat? Does that fishery practice fishing sustainably? 4. Jonathan estimated that the Giant Tridacna clam that he saw was approximately 50 years old and weighed

100 pounds. If that same clam lived to be 75 years old, how much would it weigh? If that same clam lived to be 80 years old, how much would it weigh?

5. Writing prompts: 1. Write your observations about Tridacna clams in your scientific journal. 2. Write any questions you have about clams, solar power, symbiotic relationships and over-fishing that you

would like to further research. 3. What ideas/rules/laws do you think should be implemented to prevent the extinction of the Tridacna

Clam? Specifically, should the fishermen, restaurant owners, customers all play a role in preserving the Tridacna Clam? What should each of these groups do? Who should enforce these rules? What should the penalty be if they break your rules?


(JONATHAN SWIMMING OVER THE REEF)

When I hit the water, I start to _______________ for the clam. The reef is beautiful, with _______________ coral everywhere. This is a perfect place for a Tridacna. All I have to do is _______________ around.

(JONATHAN PLAYING WITH THE CLAM)

At _______________ I see a Tridacna clam! It’s grown into the reef—so it’s a little hard to see.

It _______________ to my hand movements. That’s because it is sensitive to light and when

my _______________ casts a shadow on it, the _______________ retracts to protect itself.

This is why _______________ thought they were dangerous. Could a clam this

_______________ actually grab my hand?

Well, lets find out. I put my hand into the clam and it closes—but the clam can’t actually close

all the way. See? All my _______________ are still there. So much for the killer clam.

Listening Dictation Fill in Exercise


Rules: The Economics of Overfishing

In this simulation you will become fishermen for the day. Your task is to make as much money as you can during the four years of fishing while at the same time creating a sustainable fishery so you can keep fishing. Remember, when your ocean is depleted of fish you are out of the simulation.

Rules:

1. You will be fishing cooperatively in an ocean (a paper plate) with three other fishermen.

2. Touching, tipping, or moving the ocean is not allowed.

3. Each fisherman will be given 2 fishing poles (straws) and a net (a short length of tape) to fish with. Fishing with hands or anything else is not allowed.

4. Place the fish you catch in your boat – a paper napkin. Fish that fall out of the boat onto the table do not count!

5. You will be fishing in your ocean for 4 years. Each year you will have 30 seconds to bring in your catch.

6. There are 4 different species of fish in the ocean. The dockside market value for each fish is: Goldfish $3, Cheerios fish $5, Raisin fish $5, and Grape fish $10.

7. Each fisherman must earn at least $5 of income annually to stay in business. However, you should try to earn as much money as possible.

8. At the end of each year, the fish have a chance to reproduce. For every pair of the same species of fish left in your ocean, 2 baby fish will be born.

9. Fish need to have food in order to survive. The food web in your ocean is as follows:• Goldfish eat seaweed and there is a lot of seaweed in your ocean. • Cheerios fish and Raisin fish eat Goldfish; there must be at least 1 Goldfish in the ocean for each of these

fish to survive. • Grape fish eat both Cheerios fish and Raisin fish; there must be at least 1 Cheerios fish and Raisin fish in

the ocean for the Grape fish to survive.

The Economics of Overfishing Data Table

Number of Fish Remaining After:

Year 1 Year 2 Year 3 Year 4

Goldfish

Cheerios fish

Raisin fish

Grape fish

My Catch

# Value # Value # Value # Value

Goldfish ($3)

Cheerios fish ($5)

Raisin fish ($5)

Grape fish ($10)

My Group’s Total Income

Names Income Year 1 Income Year 2 Income Year 3 Income Year 4

My Total Income

______________________’s Income

______________________’s Income

______________________’s Income

Ocean Total Income


Diving into STEM with Oceanic Research Group … 14 STUDENT...Tridacna gigas, the giant clam, is usually blue, golden brown, yellow, or green. This clam really is a giant, growing

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