Description: In this lesson, students will learn about the Deepwater Horizon disaster and its lasting effects of the oil release on the environment. They will also learn about the importance of the wetlands of Louisiana, and the ways humans impact that ecosystem. This is intended to be the first lesson in the series of four.
Topics: Biology, Ecology, Environmental Engineering
- Discuss the importance of wetlands
- Examine ways in which wetlands are being lost
- Learn about short and long-term environmental impacts of the Deepwater Horizon disaster.
Oil Preparation Many of the following activities use oil to simulate a crude oil spill. Any type of oil may be used for these activities such as vegetable oil, baby oil, or sesame oil. For a more realistic effect, color the oil by mixing it with cocoa powder. Create Wetland Destruction Model Before class begins, you will build an island in a large paint roller tray using plasticine clay. This island will be filled with “oil” that will be drilled during the activity. To create the island: * Flatten out the clay into a circle sheet 1/4-1/8" in thickness * Place the circle of clay on top of a bowl to form a dome * Poke a small hole in the top of the dome * Gently remove the dome and place it at the lower end of the paint roller tray * Push down the edges of the dome so that it forms a water-proof seal around the bottom edge * Pour water into the top of the dome until it is full * Place the top of your spray bottle into the hole in the dome and use a small piece of clay to secure it in place and seal the hole up so air cannot enter * The rest of this wetlands model will be created in front of the students
Over the next 4 weeks, we will participate in a series of 2 hour lessons. In this series, we will learn about tracking plant health with visible and infrared light, a form of light invisible to the human eye. In today’s lesson we will learn about plants, the ecosystems they hold together, and why we want to track their health through photography. In further lessons we will learn more about types of light, how the human eye sees light, how we translate images of invisible types of light into images people can see, and how we interpret those images to understand plant health.
Our case study for plant health is coastal wetlands in the Gulf of Mexico, and the different human choices that help both damage and repair these areas.
Does anybody know what wetlands are or where they’re located? What types of life would you find in wetlands? Wetlands are areas that, at least some of the time, are covered with a shallow layer of water or have waterlogged soils. There are many types of wetlands such as bogs, swamps, and marshes. Many plants and animals such as birds, insects, and fish depend on wetlands making them the most biologically diverse of all ecosystems.
Wetlands Purpose Model
This activity may be done in small groups with each group creating its own model. Or, if preferred, make one larger model as a demonstration for the class.
* Small plastic container (if in groups) or large container such as a casserole dish (if doing as demo)
* dirt, oil, food coloring, or other items to represent pollution
* Spray bottle with water
Begin building a model of wetlands either in groups or as demo. Place clay all the way against one side of the container sloping down toward the middle of the container. The higher side will represent the land. Add rivers, lakes, or hills to the land. The lower side will represent the ocean. In our first model, we are going to build Louisiana’s coast without any wetlands.
While creating the model, tell students a little about the geography of Louisiana. Louisiana’s southern coast contains nearly half of all the wetlands in the lower 48 states. This is because Louisiana is located in the spot where the second largest river in North America, the Mississippi river, drains into the Gulf of Mexico. As the river drains, it brings mud and sediment with it that build up the wetlands in the gentle waters of the Gulf. We’re going to examine why these wetlands are so important by first seeing what happens without them. Pour a small amount of water (no more than ½ “) into the model. Have students add a few pieces of debris (sticks, dirt, food coloring) to the land as you talk about the types of pollution that happens on land (trash, oil and chemical runoff). Add approximately a teaspoon of oil to the water and mention how pollutants can come from the sea as well.
What do you think will happen to these pollutants? Will they stay on land or in the sea? Using a spray bottle with water, make it “rain” onto the land. Gently rock the container back and forth to simulate the waves and tides of the ocean. Students will observe how pollution on land runs into the ocean, and oil from the ocean contaminates the land. Now ask students to create one large wave in their model by quickly moving the container once from side to side. Ask them to notice what happened when the wave hit the land. What would happen to houses and roads that were on that land? Next, you will repeat the same experiments but using a model that has land, ocean, and the wetlands of Louisiana.
Dump out the water from your model and, using a small ball of clay, stick a piece of sponge to the area between the land and the ocean in your model. This sponge represents the wetlands. Make sure the entire “coast” is lined with a sponge.
Again, add approximately ½” of water to your model. Now add pollution to both the land and the sea, then spray with water and gently rock to create waves.
Ask students what they notice- they should see that the wetlands help filter out some of the pollution and keep it from spreading. Now have students once again create a big wave and observe how it hits the land. Students should observe that the wetlands help slow the wave and keep it from flooding the land. In addition to being a home for plants and wildlife, including many endangered species, the wetlands play a very important role in filtering out pollution and protecting the coast from flooding. Wetlands absorb many of the large waves caused by hurricanes making them vital to the inhabitants along the coast.
Wetlands Destruction Model
For this demonstration, have students gather around the model, or use a document camera to show a close up view of it.
* Paint roller pan with pre-built island (see Advanced Prep)
* 2-3 large handfuls of sand or dirt
* 1-2 paper towels
* Box cutter or sharp scissors
We know that the wetlands are important in many ways- they are home to many types of wildlife, they protect the coast from large waves, and they help filter the water, keeping our ocean clean. However, wetlands are being destroyed in many ways. An average of about 35 square miles of wetlands has disappeared every year over the last 50 years. Why do you think this is happening to the wetlands?
We are going to examine some of the ways the wetlands are being destroyed using this model.
As students watch, build the “wetlands” on the higher side of the paint roller pan. Explain each part as you build it. First, form two separate mounds of sand or dirt to represent two sections of wetlands. Cover each section with a damp paper towel to represent the many plants and plant roots that cover the wetlands. These roots act like the paper towel to hold the soil together. Fill the pan with water until much of your “wetlands” are underneath the water line. What do you think will happen when waves come in to our wetland area? Gently rock the pan and notice how, while there may be some erosion (soil loss), for the most part they remain intact. What needs to happen to keep the land in place? it needs to have lost soil replaced, as the mississippi would naturally do. Channeling of the river for transport prevents the river from distributing new sediment to the wetlands, creating a slow process of loss One of the largest reasons Louisiana’s wetlands are disappearing is due to canal cutting and dredging. Thousands of miles of canals have been cut through the wetlands so that ships can move through the area. Many of the canals are cut by oil and gas companies to lay pipeline and access drilling sites.
Use the box cutter or scissors to cut through the middle of the paper towel on your model wetlands. Gently shake the pan and observe how, with more exposed edge not held down by the “roots," more sediment is lost. As more “canals” are cut, the wetlands degrade more and more. Another cause of wetlands loss is a process called subsidence, which is the gradual sinking of an area. As oil, gas, and in urban areas water, are removed from deep below the surface of the wetlands, the land above it begins to sink.
Using the pump on the top of the spray bottle, pump the water (representing oil and gas) from beneath the surface of your clay island. You can either spray it directly into the pan, or use a separate container to catch it in. As the water inside is removed, the island will begin to collapse on itself.
News Article Readings
For this activity, arrange students into five groups.
Materials * Printed copies of Articles 1-5 (in Resource section) Recently, the Gulf of Mexico was flooded with oil during the Deepwater Horizon disaster. Ask students what they know about oil releases in the ocean. Show students a gallon container (such as for milk or water) and ask them to estimate how many gallons of oil were released during the Deepwater Horizon disaster. Give them some background information about the Deepwater Horizon disaster including: * On April 20, 2010, an oil-drilling rig named the Deepwater Horizon exploded and caused a well deep below the surface of the ocean to begin gushing into the ocean. * The oil well discharged for nearly 3 months before it could be stopped. * An estimated 200 million gallons of crude oil was released into the Gulf of Mexico. * Nearly 2 million gallons of dispersants (chemicals to break up the oil) were used to attempt to control the released oil * The spill affected 16,000 miles of coastline. What types of impacts do you think resulted from this disaster? Assign each group one of the five articles to read. Allow time for each group to read the article, and discuss it with their group members. Ask them to record at least three impacts of the oil release. Lead a class discussion about the many impacts of the oil in the Gulf. Make sure each group has an opportunity to share the information they learned from their news article. Record on the board the impacts suggested by the students.
Oil Clean Up
For this activity, arrange students in groups of 4-5 students.
Materials per group
* Tupperware container, aluminum pie tin, or similar (to hold “ocean”)
* Oil (vegetable or sesame oil work well) with a few drops of food coloring
* Dish washing detergent (Dawn works well)
* Oil-absorbing Materials such as:
* Cotton balls
* Coffee filters
* Pipe cleaners
In this activity, we will be exploring the methods of containing and removing oil from the ocean. Each group will receive a container with water (the ocean), and oil. Using the materials provided, how could we clean the oil from the ocean? How effective do you think our methods will be?
Pass out the materials and add around a teaspoon of oil to each container. Students may notice the food coloring in the oil- this represents the many chemicals within crude oil.
The edges of your container represent the land surrounding the Gulf of Mexico. In order to the minimize the damage from the oil, don’t let the oil touch the edges of your container!
Pass out all oil-containing materials to students except the dish washing detergent. Allow students time to experiment with different methods, such as spooning the oil off, making “booms” with the pipe cleaners or soaking up the oil with the sponge. Ask students to record each method as they try it, and rate its effectiveness on a scale of 1-5. After students have tried 2-3 methods of containing the oil, discuss as a class: * What methods appear to work best? * What methods are not working well? * How easy is it to keep the oil from the sides of the container? Would it be as easy in an ocean? Pass out the detergent. We mentioned earlier how millions of gallons of dispersant were used to emulsify the oil in water. Dispersants are chemicals used to break up oil into very small particles, which will then be dispersed by waves or wind. Try using a drop or two of this dispersant (dishwashing detergent) to see how it affects the oil.
After students have tested the dispersant and other materials, bring them together for a class discussion. * What happened when you added the dispersant?
* How successful were you at cleaning the oil spill from your container? * What differences would we see when cleaning crude oil from a real ocean? * How effective do you think the clean up efforts in the Gulf were based on your observations? Make sure to draw connections between the types of materials students used for the clean up and the methods used to clean real oil releases such as booms, absorbents, and skimmers. Ensure students understand that while some methods may be more effective than others, no method was able to remove all of the oil from the Gulf of Mexico.
10 minutes For this activity, students should remain in groups of 4-5 students Materials per group * small bowl or cup with dyed water * two strips of paper towel * a few drops of oil
For this activity, students may work individually, in pairs, or in groups. Or, if preferred, seeds can be planted by the teacher at any point.
Next, we will observe what happens when the oil coats plants in the wetlands. Plants depend on a process called evapotranspiration to survive, which is a combination of both evaporation and transpiration. Water vapor evaporates from the stomata (or pores) in the leaves of the plant which causes transpiration, the movement of water through the plant. When the stomata are clogged with oil, this gas exchange is blocked and plants die. We are going to see how this process works and how the oil affects the evapotranspiration.
Pass out the materials to each group. Have students coat the bottom of one paper towel strip with a few drops of oil. This will represent the stomata covered in oil. Place both strips of paper into the water making sure only the ends of the strips touch the water. After a few seconds, students will notice the stip of paper without the oil will has water climbing up it. The strip with the oil on the bottom does not. This represents how evapotranspiration is blocked when the plant’s stomata are clogged with oil. As oil coats the plants and clogs their stomata, the plants begin to die, which further contributes to wetlands loss. Materials per student * Fava or Lima beans * Paper towel * Ziplock bags Finally, we will be sprouting a seed so that it can begin growing over the next few weeks. In a future lesson, we will make changes that cause some of these plants to be unhealthy and some to remain healthy. Then we will learn how to tell the difference between the two. Pass out materials to each student. Have them dampen the paper towel and place it in the ziplock bag next to the beans. Leave this bag in a sunny spot in the classroom. Make sure the paper towel remains damp but not soaked as the beans begin to sprout and grow.
5 minutes Let students guide the discussion about the day’s lesson and present their hypotheses before discussing explanations. Why are the wetlands important? What is happening to the wetlands of Louisiana today? What are some of the effects of drilling along the Gulf Coast?
http://news.nationalgeographic.com/news/2011/04/110420-gulf-oil-spill-anniversary-health-mental-science-nation/ Article 1: A year after the spill, “unusual” rise in health problems. http://news.nationalgeographic.com/news/2010/11/110127-gulf-oil-spill-dispersants-environment-science/ Article 2: Gulf Spill Dispersants Surprisingly Long-lasting http://news.nationalgeographic.com/news/2010/06/100608-gulf-oil-spill-birds-science-environment/ Article 3: Oil-Coated Gulf Birds Better Off Dead? http://news.nationalgeographic.com/news/2011/04/pictures/110420-gulf-oil-spill-anniversary-animals-birds-science-nation/ Article 4: Gulf Spill Photos: 9 Animal Victims—Plus 2 Survivors http://www.nature.com/news/2010/100901/full/467022a.html Article 5: Deepwater Horizon: After the oil http://education.nationalgeographic.com/media/file/A_Geography_of_Offshore_Oil-Map.pdf Map of the Gulf Coast and the offshore drilling in the area http://fas.org/sgp/crs/misc/R41311.pdf The Deepwater Horizon Oil Spill: Coastal Wetland and Wildlife Impacts and Response http://education.nationalgeographic.com/education/activity/rescuing-relocating-and-rehabilitating-wildlife/?ar_a=1 National Geographic lesson on wildlife and the oil spill http://ngm.nationalgeographic.com/2010/10/gulf-oil-spill/barcott-text Article about the impacts of the oil spill on the wetlands and the local economy http://www.nwf.org/pdf/Eco-schools/WhatMakesaWetlandaWetland-2.pdf Information on importance of and types of life found in wetlands. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1332684/ Focus on importance of Louisiana’s wetlands and reasons they are disappearing.
Description: In this lesson, students will explore the properties of both visible and IR light, as well as how we perceive light and color. This is intended to be the second lesson in the series of four. Topics: Electromagnetic Spectrum, Physics, Biology
- Understand the properties of the Electromagnetic spectrum
- Experience the ways our eyes perceive light and color
- Explore mixing of light vs mixing of pigments
Create Boxes with Red Filters (1 per student group) * Cut hole in side of box approximately 3” by 3” hole * Cover hole completely with red colored film * If time allows, have students help with the construction of these boxes
5 minutes Begin class by going over classroom expectations, and reminding students of the information learned in Lesson 1: [xxx]. In our last lesson, we learned about the wetlands loss occurring in the gulf and the importance of protecting these lands. Today, we’re going to study light, and how we see light, so that we can learn more about how to observe and protect our environment around us.
10 minutes What is light? Light is electromagnetic radiation that is visible to the human eye. You may have heard of the term “visible light” does that mean there is also “invisible light”? What other types of light are there? Electromagnetic radiation that is outside the visible range has a wavelength that is too long or too short for the human eye to detect. Humans can only see a small portion of the electromagnetic spectrum! Electromagnetic radiation is classified by its wavelength. The human eye can typically see wavelengths between approximately 400700 nanometers, but this range is just a small fraction of the entire spectrum. Below 400 nanometers is ultraviolet, or UV, light, X rays, and gamma rays. Above 700 nanometers is Infrared, or IR, microwave, radio waves, and long radio waves. Today we will be taking a closer look at visible light, as well as IR light that is very near the visible light spectrum, also known as nearinfrared. Visible light is made up of all the colors of the rainbow red, orange, yellow, green, blue, and purple. When all these colors combine, we see “white light”.
20 minutes For this activity, arrange students in small groups of 2-4 students. Materials * Boxes with red filter * Small colored objects * Flashlight * Filtered light worksheet When we look at a object, why does it look a certain color? When light hits an object, the object will either absorb or reemit that light. The color of an object is just a combination of all the wavelengths of light that were reemitted by the object. A red object appears red because it is absorbing the orange, yellow, green, blue, and purple wavelengths, and is reemitting the red wavelengths. Why do white objects look white? What about black objects? White objects are reflecting all wavelengths of visible light. Black objects are absorbing all wavelengths of visible light.
Pass out the filtered light worksheet to each group and have them draw what happens to the visible light wavelengths in Section A. After each group has had a chance to complete Section A, review with the class to check for understanding. Pass out a box with red filter and a flashlight to each group. In front of you, you each have a box with a red filter on the side. What do you think happens to light as it enters this filter? Only the red wavelengths of light are able to pass through this filter. In a moment, I will be passing out a few colored objects, including a red, black, and white object. On your worksheet in Section B, make a prediction about what color each of these objects will appear when viewed through the red filter. Once you receive your objects, place them in the box and use the flashlight to shine through the filter and view your objects one at a time. Pass out small colored objects to each group. After students have a chance to test out each of their objects, review as a class and discuss why each object appeared as it did.
20 minutes Materials * Flashlights * Squares of colored film (blue, red, and green) * White paper * Worksheet You likely learned about mixing colors when you were in elementary school. However, most of our experience with mixing colors usually comes from mixing pigments. This is very different from the results of mixing light. For example, when you mix all colors of the rainbow with paint, you get a lovely shade of brownish black. However, when you mix all colors of the rainbow in light, you get white light. We are going to experiment with mixing light using the colored filters and flashlights in front of you. Pass out the materials listed above to each group. First, have students use the worksheet to predict what color will form when they mix each of the colors of light, and what color will form when mixing all three colors. Then, instruct students to place a colored film on each flashlight and shine it onto the white piece of paper. Have them begin by mixing two colors at a time, then all three colors at once. Students should color in the light color wheel on their worksheet with the results. Discuss their predictions and the results of their experiment. Students should observe that mixing red and green light results in yellow light, mixing red and blue results in magenta, and mixing green and blue results in cyan. Mixing all three results in white light. These three colors of light are known as the primary color because when they combine they can create all other colors of light.
Biology of Our Eyes
We now know how visible light can be reflected or absorbed and combined to form different colors. But how do our eyes detect those colors? Our eyes have millions of lightreceptor cells of two types: rods and cones. Each of these types have a very different purpose. Cones can detect color, while rods cannot. Rods are extremely sensitive and can detect light at very low levels. If you’ve looked around a dark room, chances are there was still enough light for you to make out different objects, but not enough light to tell what color the objects were. This is because at low levels of light, only your rods are active. Cones need a much brighter amount of light to activate. There are three types of cone cells those that respond to long wavelengths, medium wavelengths, and short wavelengths. These allow us to see red, green, and blue light. We know from our light mixing experiment that these three colors of light can be mixed in different amounts to produce all other colors of light.
20 minutes Materials * Optical Illusion Prints * False Color Photographs * White Paper * Markers Pass out optical illusion prints to students. Ask them to stare at the middle of the print for one full minute, then look at their blank white paper. Students will observe an afterimage on the white paper that has different colors from the print. What did you observe? Why do you think you see the same image when you look away? What you observed when you looked at the white paper is called an afterimage. You may have seen this effect before if you’ve experienced seeing spots of lights in your vision after looking at a camera flash. This happens because the rods and cones in your eyes lose sensitivity if they are over stimulated. Were the colors the same in the afterimage as they were in the original image? The colors were not the same. Your task is to figure out how the colors in the afterimage are related to the colors in the original image, and why they appear different. You can use the markers and white paper to test various colors and make your own optical illusions. After allowing time for the students to experiment, discuss their results. They should discover the following connections:
Encourage students to refer to the color wheel of light they created in the previous activity. They will notice a pattern in the colors of the afterimage: The afterimage is of a color across the color wheel from the original color. For example, if the original image is green, the afterimage will be magenta. This is because the green photoreceptors are fatigued, making the signal from the red and blue photoreceptors stronger by comparison. Sensing red and blue light together forms a magenta image. Similarly, an original yellow image is made from both red and green light. As the cones that sense red and green are fatigued, the blue photoreceptors are stronger by comparison and create a blue afterimage. If time allows, let the students draw their own optical illusions keeping in mind what colors the afterimage will appear. Have them trade pictures with their neighbors and view their optical illusion.
10 minutes Let students guide the discussion about the day’s lesson and present their hypotheses before discussing explanations. What is the electromagnetic spectrum? How much of the electromagnetic spectrum can humans see? How do we see light? What surprised you about today’s lesson? What would you like to learn more about from today’s lesson?