Cadmium at Foundry Cove: An Ecology & Evolution Story

Cornelia Harris

Today’s Workshop• Quick overview of the Changing Hudson

Project• What do students know about evolution? • Lesson overview• Share ideas, Questions

Research & Education based on Ecosystem Ecology

Changing Hudson Project: Ecology Curriculum for the High School

Classroom

Changing Hudson Project• Help students understand

how the Hudson River estuary changes over time using local data

• Train educators through weekend, evening and summer workshops

Resources: Visualizations, Readings, Lesson Plans with worksheets & labs

What do students think about how evolution works?

• Work in groups• Sort the answers in order of increasing

sophistication• Fill out the first column of the worksheet: what

characteristics are you using to sort the students’ answers into different levels?

• Write the letter of the student responses in the second column (teacher generated rubric); leave the last column blank for the “answers”

Change in Population Questions

Level 4 for change in a population: NY 12th grader: This occurs because the pesticide wipes out

all of the non-resistant insects thus leaving the resistant insects to breed and reproduce and become a dominate trait in the population.

INTERVIEWER: Okay. How does an insect become resistant? NY 12th grader: It's born with natural variation in genetic

population. If there's a 100 bugs maybe 10 are resistant and then when the whole population is sprayed those 10 are left. So when the population eventually recovers those 10 will be the, will now be the entire 100 or they will be make up a large part of it and if the same pesticide is used over and over again eventually it won't have an effect because the entire population will be resistant to it.

Change in Population Questions

Level 1 for change in a population: CO 7th grader: The increase in resistance is most likely

caused by the evolving animals in the environment of a farm. Lately we have talked about the changes animals and/or organisms use to change and adapt to their environment. These insects highly adapt to avoid the chemicals.

INTERVIEWER: Okay. How do they evolve? CO 7th grader: They evolve by adapting to their

surroundings or doing something to make them – make better use of their surroundings.

INTERVIEWER: Okay. And so – do you know anything about mechanism? So how does – how do they adapt?

CO 7th grader: Probably just by finding different ways to use their surroundings or finding different ways to do something.

Change in Population: InsecticidePr

opor

tion

of A

nsw

ers

Middle School High School0%

10%

20%

30%

40%

50%

60%

70%Level 1 Level 2 Level 3 Level 4

n = 187 n = 160L1-4 = 80% L1-4 = 85%

What do students know and think about how evolution works?

• Understanding adaptation by selection and phenotypic plasticity are both important for predicting effects of disturbances, including climate change and other human impacts, on ecosystems

• When asked why a population may have changed over time, students describe an individual gaining or losing traits based on some environmental cue

• When given enough scaffolding, even young students can understand that there is standing variation in a population and a trait can increase in a population over time through differential reproductive success

• We propose understanding the mechanism of adaptation by selection is not what is limiting students understanding of how individuals and populations change: instead we propose that understanding the nature of phenotypic traits - and thus the existence of standing variation in a population - is their largest hurdle.

• Key problems that plague students: they don’t really understand what a population is, and they don’t think about multiple generations

What makes the Hudson a unique river ecosystem?

What do you already know about the Foundry Cove story?

Cadmium in the Cove

Scientists collecting samples in Foundry Cove

FOUNDRY COVE

SOUTH COVE

NORTH COVE

1.0 km

N

NEW YORK CITY

FOUNDRY COVE

200 km

N

Marathon Battery Factory made nickel-cadmium batteries in Foundry Cove from 1952-1979.

Heavy Metal Pollution between 1952

and 1979, over 112,000 pounds of cadmium was released into Foundry Cove

Foundry Cove became “the most cadmium polluted site in the world”

nickel and cobalt were released in much smaller amounts

How could scientists find out where the cadmium went after it left the Marathon Battery outfall?

= 50,000+ ppm cadmium in sediments of Foundry Cove ppm = parts per million

1975

Marathon Battery Factory

1975Distribution of cadmium in surface sediments in East

Foundry Cove

1983Distribution of cadmium in surface sediments in East

Foundry Cove

What changed?

Marathon Battery

Map activity

Cadmium in sediments of Foundry Cove

What happened to the cadmium between 1979 and 1983?

Where could it have gone?

Sampling at the train trestle, Foundry Cove

Outgoing Tide Incoming

What happens to cadmium that gets

eaten?

Cadmium in

sediments of Foundry

Cove

Major Cadmium Pathways

Transported out by tides

Eaten by organisms

Buried by sediments carried in by tides or freshwater runoff

Redistributed by waterMovements within the cove

Part B of worksheet

ELA connections• CCS ELA Reading Standards 6-12: Cite specific

textual evidence to support analysis of science and technical texts

• CCS ELA Reading Standards 6-12: Determine the central ideas or conclusions of a text; provide an accurate summary of the text distinct from prior knowledge or opinions

Overview of Unit

• Lesson 2: Marathon Battery Factory (dilution activity)

• Lesson 3: Biomagnification (mobile or poster)• Lesson 4: Survivors at Foundry Cove (what

happened to the worms in the toxic mud?)• Lesson 5: Natural Selection• Lesson 6: Evolution & Pollution

What’s so bad about a little cadmium?• At very high levels, causes Itai-Itai (or ouch-ouch)

disease in humans – pain in bones and joints, bones break easily

• Can cause cancer and other health problems

• Entered the human food web via contaminated blue crabs in the Hudson River

• Liver lesions in muskrats in Foundry Cove

Lesson 3

Looking at a Millionth - Activity

100 ppm

1,000 ppm

10,000 ppm

50,000 ppm

How big is 1 ppm?

How big is 250,000?

Lesson 3

30

Survivors at Foundry Cove

How did the worms in Foundry Cove survive when their environment became highly contaminated by toxic cadmium?

Lesson 4

31

Scientific experiments were conducted on Limnodrilus hoffmeisteri worms.

Sampling for worms in Foundry Cove Lesson 4

32

L. hoffmeisteri

cadmium

Lesson 4

33

Foundry Cove South Cove

Very similar environments

Extreme Cd contamination

50,000 ppm

Lower level of Cd contamination

19 ppm

Mud worm dominant mud-dwellers

Lesson 4

34

Are L. hoffmeisteri worms usually resistant to cadmium?

What kind of experiment could be

done to find out? Pause here to discuss your ideas. Then describe and sketch an idea for an

experiment to answer the question. Lesson 4

35

Are all L. hoffmeisteri worms resistant to cadmium?

Control Area Foundry Cove0%

10%

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70%

80%

90%

100%

Graph A: Numbers of Limnodrilus hoffmeisteri worms surviving sediment exposure after 28 days

Foundry CoveControl Area

Sediment Source

Perc

ent S

urvi

ving

Worms from

Lesson 4

“Adaptation”, Evolutionary adaptation or plasticity?

• A squirrel lines its nest with grasses and leaves because it has suddenly become very cold outside – “adaptation”

• Twin dogs, separated at birth, grow to different sizes because they have access to different types of nutrition– plasticity

• A rabbit grows white fur in the winter – the mechanism is an evo adaptation

• A species of mosquito has been going dormant later each fall – evo adaptation

• Butterfly species in CA are migrating an average of 24 days earlier when compared to 30 years ago– plasticity

37

Resistance to Toxins

• Physiological plasticity:– In individual organisms

– Depends on environmental conditions

– Disappears if returned to a clean environment

• Heritable trait:– In populations of organisms

– Increased through natural selection

– Persists in offspring for at least a few generations Lesson 4

38

Did Foundry Cove worms pass their cadmium resistance to their offspring?

O 20 30 45 65 900

10

20

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50

60

70

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90

100

Graph B: Limnodrilus hoffmeisteri Survivors

Foundry Cove wormsFoundry Cove offspringSouth Cove worms

Cadmium level in sediment (mg Cd/g of dry sediment)

Perc

enta

ge o

f Sur

vivo

rs

39

Natural Selection at Foundry Cove: Evolution of

Cadmium Resistant Worms

Part 1Of Mice, Bugs, and

Bacteria

Part 2Mud worms

Source: www.smc.edu Source: www.fcps.edu

Lesson 5

40

How did Foundry Cove worms become resistant to cadmium?

Natural Selection

Natural selection of an invisible trait such as cadmium resistance is hard to visualize.

So let’s first look at natural selection of a visible trait such as fur color.

Source: museum2.utep.edu Lesson 5

41

Pocket Mice and Predation

http://www.hhmi.org/biointeractive/evolution/pocket_mouse_predation.html

Source: www.nps.gov

Lesson 5

42

Pocket Mice and Evolution

http://www.hhmi.org/biointeractive/evolution/pocket_mouse_evolution.html

Lesson 5

43

Existing Variation

Variation within a species

e.g. Genetic variation for fur color-multiple alleles for color

Present in a population or species before natural selection occurs

Lesson 5

44

Natural Selection in a Population of Pocket Mice

• Existing genetic variation multiple alleles for fur color

• Heritable fur color is passed from parent to offspring

• Differential succcess dark fur protects mice better than

light fur on lava flow habitat

• Time many generations of mice have lived and passed on

their genesLesson 5

45

Evolution of an Invisible Trait

Now, on to the natural selection of cadmium resistance in Foundry Cove mud worms.

Source: www.spiegel.de

Lesson 5

46

Foundry Cove WormsNatural Selection Process Diagram

Key= Non-resistant worm= Resistant worm

Selection and Growth

Toxic levels of cadmium kill 50% of

the population

First Generationas Young

How many are alive?

What % are resistant?

Lesson 5

47

Foundry Cove WormsNatural Selection Process Diagram

Key= Non-resistant worm= Resistant worm

Selection and Growth

Toxic levels of cadmium kill 50% of

the population

First Generationas Young

First Generationas Adults

How many are alive?

What % are resistant?

How many are alive?

What % are resistant?

Lesson 5

48

Foundry Cove WormsNatural Selection Process Diagram

Key= Non-resistant worm= Resistant worm

ReproductionSurviving adults reproduce, each having one baby

Selection and Growth

Toxic levels of cadmium kill 50% of

the population

First Generationas Young

First Generationas Adults

1st Gen. Survivors & their Young

How many are alive?

What % are resistant?

How many are alive?

What % are resistant?

How many are alive?

What % are resistant?

Lesson 5

49

Foundry Cove WormsNatural Selection Process Diagram

Selection and Growth

Toxic levels of cadmium kill 50% of

population

ReproductionSurviving adults reproduce, each having one baby

Key= Non-resistant worm= Resistant worm

1st Gen. Survivors & Their Young

(Copy)

1st & 2nd Gen. Survivors as Adults

Survivors & theirYoung

ReproductionSurviving adults reproduce, each having one baby

Selection and Growth

Toxic levels of cadmium kill 50% of

the population

First Generationas Young

First Generationas Adults

1st Gen. Survivors & their Young

How many are alive?

What % are resistant?

How many are alive?

What % are resistant?

How many are alive?

What % are resistant?

How many are alive?

What % are resistant?

How many are alive?

What % are resistant?

Copy totals for 1st gen. survivors & young here:

Lesson 5

50

Scientists noticed fewer muskrats in Foundry Cove during the most polluted years.

1. Do you think muskrats evolved resistance to cadmium? Why or why not?

2. What else might cause a reduction in the number of muskrats in the cove?

Source: www.fcps.org

Lesson 5

Lesson 6: Evolution & Pollution

• Tomcod resistance to PCBs in the Hudson River

• Students get a variety of articles to choose from – they select one, read it & critique

52

1. Scientists have discovered a strange fish that lives in a soup of some of industry's worst pollutants.

2. Bottom-feeding fish in the Hudson River have developed a gene that renders them immune to the toxic effects of PCBs, researchers say.

3. An unpretentious little fish that has learned how to thrive in one of the most polluted rivers in North America has scientists wondering if foul water is driving its evolution and, ironically, whether genetic changes that seem to be taking place might jeopardize its ability to survive in cleaner water.

4. IT IS not often that biologists have a chance to watch natural selection in action.

5. Some fish in New York’s Hudson River have become resistant to several of the waterway’s more toxic pollutants.

6th grade 11th-12th grade

CCSS.ELA-Literacy.RI.6.1 Cite textual evidence to support analysis of what the text says explicitly as well as inferences drawn from the text.

CCSS.ELA-Literacy.RI.11-12.1 Cite strong and thorough textual evidence to support analysis of what the text says explicitly as well as inferences drawn from the text, including determining where the text leaves matters uncertain.

CCSS.ELA-Literacy.RI.6.3 Analyze in detail how a key individual, event, or idea is introduced, illustrated, and elaborated in a text (e.g., through examples or anecdotes).

CCSS.ELA-Literacy.RI.11-12.3 Analyze a complex set of ideas or sequence of events and explain how specific individuals, ideas, or events interact and develop over the course of the text.

CCSS.ELA-Literacy.RI.6.5 Analyze how a particular sentence, paragraph, chapter, or section fits into the overall structure of a text and contributes to the development of the ideas.

CCSS.ELA-Literacy.RI.11-12.5 Analyze and evaluate the effectiveness of the structure an author uses in his or her exposition or argument, including whether the structure makes points clear, convincing, and engaging.

CCSS.ELA-Literacy.RI.6.7 Integrate information presented in different media or formats (e.g., visually, quantitatively) as well as in words to develop a coherent understanding of a topic or issue.

CCSS.ELA-Literacy.RI.11-12.7 Integrate and evaluate multiple sources of information presented in different media or formats (e.g., visually, quantitatively) as well as in words in order to address a question or solve a problem.