Ecosystem Indicators - The Boreal Toad Case Study

Created Feb. 5, 2024 by Katie Garrett

Ecosystem Indicators

Grade: 6th
Science Discipline: Life Science
Utah SEEd Standard: 6.4.4 Construct an argument supported by evidence that the stability of populations is affected by changes to an ecosystem. Emphasize how changes to living and nonliving components in an ecosystem affect populations in that ecosystem. Examples could include Utah ecosystems such as mountains, Great Salt Lake, wetlands, and deserts.
Disciplinary Core Ideas:	Featured Crosscutting Concept:	Featured Science Practice:
Interdependent relationships in ecosystems. Organisms interact with the environment in ecosystems.	Cause and effect. Stability and change.	Ask questions and define problems. Planning and carrying out investigations. Engage in argument from evidence. Obtain, evaluate and communicate information.
Performance Tasks:	Plan and carry out an investigation on how changes to the ecosystem affect amphibians due to their unique adaptations. Construct an argument about how changes in the ecosystem affect amphibian populations and in turn other populations that live there.
5E Instructional Sequence *Engage* The teacher engages students with a phenomenon. Students generate questions and make a claim.Phenomenon= Amphibian populations are declining in Utah.(Show population graph of boreal toads that is provided) Students ask questions and generate claims about possible causes for large-scale amphibian mortality Students will share their claims for possible cause of amphibian population decline with the class. *Explore* Students explore the phenomenon and gather evidence to support or refute their claim. [Teacher Hint: Now would be a good time to give some background information on amphibians and boreal toads specifically. Make sure you tell students that Boreal toads are toads that live in high elevation wetlands like Strawberry Reservoir and Bryce Canyon. Define an amphibian as an animal that spends some of its life cycle on land and some in the water. They are cold blooded animals that lay soft eggs and have moist, permeable skin, which means things like water and oxygen can be absorbed through their skin. Scientists consider them to be an indicator of ecosystem health, because if there is a change in the ecosystem, their population is usually one of the first to change.] Students will discuss with a partner why they think amphibian populations are more susceptible to change than other population in the same ecosystem, given the new information about boreal toads and amphibians. Students read provided handouts to obtain information on changes to the boreal toads’ ecosystem and their effect. There are three reading provided, each student should read one of them. As a group of three, students will discuss the information they have learned from their reading with students who have read the other readings. *Explain* Students explain the phenomenon using evidence and reasoning to support their claim. Introduce new vocabulary as needed.Students develop a written argument based on evidence to support the claim on which environmental change has the largest impact on boreal toad populations and why. *Elaborate*Students apply knowledge to solve a problem, or explore and explain a new but related phenomenon.Phenomenon= Many populations of amphibians are decreasing worldwide (show provided graph) Students will plan and carry out an investigation about global causes of decline in amphibian population by obtaining information from provided readings, graphs and reliable sources. Students will discuss with a partner what information they have found and possible changes lower amphibian populations might have on their ecosystem. Willing partners should share their ideas with the class. Students will revise their written argument as needed and include their ideas for possible ways other parts of the ecosystem might change due to boreal toad population changes. *Evaluate* The teacher administers formative assessments throughout. Provide exemplar here.Rubric is attached
Materials: graphs, reading and worksheets attached, paper, pencils

Phenomenon graph information from

Utah Division of Wildlife Resources (UDWR)

Second phenomenon graph info from 2008

International Union for Conservation of Nature (IUCN) Red List

Chytrid Fungus

Chytrid (pronounced keh-tred) is a group of fungus that lives underwater and grows where there are dead plants or animals. It is found in every continent except Antarctica and can be found in Utah. There is one kind of chytrid that is known to grow and feed on living amphibians. The fungus will grow on their skin and can easily pass from one amphibian to another. This fungus causes damage to their skin, which they use to breathe and drink through, and can be deadly.

Amphibians that are sick from chytrid often have red looking skin and act strangely. Scientists have observed them like resting with their rear legs stretched out, swimming in circles and sitting out in the hot sun when they would normally find shade or go in the water. This makes them an easy target for predators to catch.

Scientists have been studying chytrid for many years and have found that it has caused many species of amphibians to go extinct. They have also learned that there are some amphibians that can have chytrid and not get sick. The African clawed frog, which is a common pet and is used in laboratories, is one of those frogs. Scientists think that is one way this type of chytrid fungus has spread has been people letting this frog go in the wild when they aren’t aware that it has chytrid. When that happens, the frog passes on the fungus to other amphibians in its new habitat.

Fungus: A living thing that is not a plant, animal or bacteria. They are often confused as plants but they do not create their own food and their cells are made differently. The most common example of a fungus is a mushroom.Amphibian: A group of animals that are cold blooded, have back bones and do not have scales. They live in the water when they are young but most live on land as adults. Frogs, toads, salamanders and newts are all amphibians.

Habitat Loss

Amphibians are animals that lay their eggs in water, live in the water when they are young and most live on land when they are adults. Frogs, toads, and salamanders are all examples of amphibians. Their life cycle and adaptations make it so that most of them have to live in habitats that have a lot of water in them like wetlands.

There are a number of different ways that habitat loss can happen. One way is that as homes and other buildings that people need are made they are built on top of what was once a wild area. The animals that lived there then have to find new places to live. Another way that amphibians lose their habitats is when wetlands dry up. This happens when water is taken from one place to another, too much is used, dams are built or when droughts happen.

When animals lose their habitat they face a number of challenges. Every animal needs food, water, shelter and the right amount of space. When habitat is lost, so are those things that they need. Some animals will try to move and find new habitats to live in, but they might not be able to. Other animals might stay where they have lived but can have difficulty finding the things they need to survive and might have a conflict with people.

Habitats: Where a plant or animal lives.Dams: A structure that blocks flowing water.Droughts: Wherever there is a shortage of rain over a long period of time.

Pollution

Amphibians are animals that have unique skin. Their skin is permeable which means that some things can go in and out of it. An amphibian, like a boreal toad, will use its skin to drink and breathe. Amphibians are sometimes called ecosystem indicator species because their skin makes them very sensitive to changes in their ecosystem. If something is in their ecosystem that shouldn’t be, the number of amphibians in that habitat will go down.

Since they absorb things through their skin, pollution can make amphibians very sick or make it so they don’t grow correctly when they are young. Pollution can be a problem that can be hard to fix because it washes into the wetland habitats that the amphibians live in and it can be from something many miles away. Some of the most common pollutants that impact amphibians are things like pesticides and herbicides that can wash away from farms and peoples yards and into the waterways.

Amphibian: A group of animals that are cold blooded, have back bones and do not have scales. They live in the water when they are young but most live on land as adults. Frogs, toads, salamanders and newts are all amphibians.Unique: Unlike anything else.Absorb: To soak up.Pollution: When something has something that it is no supposed to have in it that can be harmful. Examples can be chemicals and garbage. Pesticide: Chemicals used to kill insects and other pests.Herbicide: Chemicals used to kill weeds.Indicator: something that can alert others about the condition of something.

Rubric for writing assignment

	Excellent (5)	Good (4)	OK (3)	Needs Improvement (2)	Poor(1)
Spelling and grammar	No spelling or grammar errors	Few spelling or grammar errors	Some spelling or grammar errors	Many spelling or grammar errors, but can still be understood	It is hard to read the paper due to spelling and grammar errors
Evidence used	Evidence from the readings and student investigation is clearly used and its source is clearly addressed. Evidence used supports their argument.	Evidence from both student investigation and readings is used, but where they got the evidence could be more clear.	Evidence from only reading or student exploration or does not support their argument.	Little evidence is used and not clearly addressed where evidence came from.	No evidence from the readings or student investigation is used.
Argument	The writing clearly supports an argument for what the student has decided to be the best answer to the question. Reasoning for their argument is well reasoned and easy to understand.	Writing supports one clear argument. Reasoning makes sense but could be easier to understand.	Writing supports one clear argument, but reasoning is weak.	Student doesn’t have one clear argument.	The language used in the paper is not argumentative.
Revision	There has clearly been changes from the first draft. These changes strengthen their argument, correct spelling and grammar errors and add more evidence.	Changes have been made and their argument is strengthened, but there is room for further improvement.	Some changes have been made but they do not strengthen the student’s argument.	Only minor changes were made from the first draft	No changes have been made from the first draft

Teacher information

A quick note: This lesson is designed to teach students about ecosystems and how changes can have a dramatic effect on some of the animals that live there. One of the types of animals that are the least able to tolerate change are amphibians. Amphibians have a very unique skin that is permeable and they are able to breathe and drink through their skin. Because of this, anything that damages their skin like disease, anything that might dry them out and pollution tend to be lethal for them. Around the world Amphibian species have been declining to the point of extinction at an alarming rate. These changes have been seen here in Utah as well. Utah’s Hogle Zoo and the Utah Division of Wildlife Resources have formed a partnership to try to study and protect local amphibians that are declining like the boreal toad.

For more information on this partnership, click here: https://www.hoglezoo.org/meet_our_animals/conservation/boreal_toad_conservation/

Or watch these videos: http://www.scitechnow.org/videos/fighting-toad-fungus/#

For more information on how their skin works, click here:https://www.amnh.org/exhibitions/frogs-a-chorus-of-colors/a-frog-s-life/thin-skin/

https://www.brown.edu/Departments/Engineering/Courses/En123/MuscleExp/Frog%20Respiration.htm

Some of the threats that amphibians face worldwide are disease, habitat loss and climate change and pollution. One of the most well known diseases that is causing amphibian decline is Chytridiomycosis or an infection from the chytrid fungus. This disease can be complicated to understand. It is caused when the fungus gets into the amphibians skin and makes it difficult for them to breathe and drink the way they should. How poorly it affects the animals varies by species. There are some species that are immune to it while others have a 100% mortality rate This is the primary concern with the boreal toad in Utah. When talking to children about amphibian conservation one of the most important things they can do is to not pick up wild amphibians or release ones that have been in human care. Doing these things is thought to be a major reason that the chytrid fungus has had such a global impact.

watch this video: https://www.youtube.com/watch?v=BvidpapF1bg

Reliable resources for students

Videos:

https://www.youtube.com/watch?v=14bIz89d7QY -National Geographic video on chytrid fungus in South America

https://www.youtube.com/watch?v=XI8GPsf6TAc- video on basic amphibian facts

http://www.scitechnow.org/videos/fighting-toad-fungus/#= video about boreal toads

Websites:

Website on amphibians and chytrid fungus

http://www.environment.nsw.gov.au/topics/animals-and-plants/native-animals/native-animal-facts/frogs/threats-to-frogs/frog-chytrid-fungus

New York Times article on amphibians and pollution

https://www.nytimes.com/2008/04/08/science/08frog.html?mtrref=www.google.com&gwh=6FB0BBBE6629737CF3F123532D906FB7&gwt=pay

National Park Service website on threats to reptiles and amphibians