SHARKS AND SHORELINES
Subject: Science
Grade level: 6-10
Purpose and Overview:
This set of activities is divided into three parts. In Part 1, through a short video and reading, students learn about lemon sharks, their impact on the mangrove ecosystem, and the threats to sharks worldwide. In Part 2, students partake in a quest to learn about great white sharks and their prey through a series of interactive, online components including real-time data and visualizations. In this activity they identify a shark to track online and then examine the shark’s path and make inferences about where it goes and why. In Part 3, students engage in an outdoor activity designed to teach them about predator/prey relationships in a marine environment. Students assume the roles of predator and prey and through several iterations of the game; they will understand how populations of predators and prey are interconnected.
Time:
· Part 1: One to two 45-minute class periods
· Part 2: Two 45-minute class periods
· Part 3: Two to three 45-minute class periods
Introduction:
Through the use of tagging technologies, scientists have been able to track the paths of many marine predators like sharks, seals, and tuna. This information is vital in the conservation of marine animals because it allows scientists to understand potential threats to species where human activities like fishing may overlap migration routes, breeding grounds, and feeding grounds. Additionally, by collecting tracking data on marine animals, scientists can begin to build a picture of the whole marine ecosystem.
In the Sharks and Shorelines | EARTH A New Wild video associated with this set of activities, shark tracking data allowed scientists to identify one of the breeding grounds for the lemon shark: shallow, coastal waters. Scientists determined that these sharks return to the same place every year to give birth. The presence of the sharks controls grazing behavior and ultimately keeps marine herbivores like manatees and sea turtles from overgrazing the mangrove habitat. When the mangroves are intact, they have a role in protecting the coasts from storm surges and coastal erosion. This predator-prey relationship is vital to keeping the mangrove ecosystem strong, which in turn helps keep human habitats from being ruined in the event of a hurricane or powerful tropical storm.
Part 1: Lemon Sharks and Mangroves
Grades: 6-10
Subject: Science
Purpose: The purpose of this activity is to introduce students to the role that lemon sharks play as predators in a marine ecosystem and to relate the behavior of lemon sharks to the preservation of the mangrove forest and the protection of our coasts. Students will also learn about the threats to sharks worldwide and how tagging helps in conservation efforts.
Time: One to two 45-minute class periods
Materials:
· Teacher - computer, internet access, LCD projector
· Sharks and Shorelines | EARTH A New Wild video (3:56 min)
URL: https://vimeo.com/116273821
· Copies of student worksheet for Part 1 (located at the end of this document)
· Small whiteboards or sheets of drawing paper and markers
· Student copies of the National Geographic article “Blue Waters of the Bahamas”
URL: http://ngm.nationalgeographic.com/print/2007/03/bahamian-sharks/holland-text
· Optional – student access to computers to explore interactive content for the shark ecosystem
URL: http://www.pbslearningmedia.org/resource/5aeed659-7f0b-417f-81d9-5f2e9c747644/ecosystem-explorer-earth-a-new-wild/
Objectives:
The student will….
· List the ocean herbivores that can impact a coastal ecosystem.
· Describe how sharks maintain the coastal ecosystem through intimidation behavior.
· Identify how the tagging of sharks helps scientists to learn more about their behavior.
· Relate how tagging data improves shark conservation efforts.
· Describe how humans are impacted by the sharks’ presence.
· Illustrate the threats to sharks worldwide.
· Predict what would happen if sharks, an apex predator, were removed from an ecosystem.
· Evaluate how humans can help conserve sharks.
Next Generation Science Standards:
Disciplinary Core Ideas:
· LS2A Interdependent Relationships in Ecosystems
· LS2B Cycle of Matter and Energy Transfer in Ecosystems
· LS2C Ecosystem Dynamics, Functioning, and Resilience
· LS4D Biodiversity and Humans
Crosscutting Concepts:
· Cause and Effect
· Stability and Change
Performance Expectations:
Middle School
· MS-LS2-1. Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
· MS-LS2-2. Construct an explanation that predicts patterns of interactions among organisms across multiple ecosystems.
High School
· HS-LS2-6. Evaluate the claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem.
Vocabulary:
Bycatch: fish or other organisms caught while actually fishing for another species or target fish.
Ecosystem: a biological community of organisms interacting with the biotic (living) and abiotic (nonliving) components of their environment.
Finning: refers to the removal of shark fins while the remainder of the living shark is discarded into the ocean. Shark fins are in high demand in some parts of the world for use in shark fin soup and traditional cures, in which shark fins are an ingredient. Because fins are worth a lot of money compared to the rest of the shark, fishermen can collect more fins if they harvest them while at sea and throw the rest of the shark overboard. Sharks with their fins removed cannot swim and will eventually perish.
Herbivore: an animal that eats plants.
Longline fishing: a deep-sea, commercial fishing technique in which a really long line (often several miles long) with baited hooks spaced at intervals is used to catch fish; also called longlining. Longline fishing can have serious consequences for sea turtles and sharks when they are caught as bycatch. Sea birds are vulnerable when the longlines are set because they are attracted to the bait.
Mangrove: a tree or shrub that grows in coastal swamps that are flooded at high tide. Mangroves can protect coastlines from erosion and flooding.
Predator: an animal that preys on or eats others; sharks are predators.
Prey: an animal that is hunted and killed by another animal for food.
Suggested Flow for Part 1:
Section A: Video Viewing Guide
1. Distribute copies of the student worksheet for Part 1 so that students can answer the video viewing questions while they are watching the Sharks and Shorelines video. Go over the questions with students so they know what to look for during the video.
2. Show students the video and then give them time to complete any questions on the worksheet that they were unable to answer and then go over questions with the students.
3. Be sure to emphasize with students that the sharks’ presence in the mangrove acts as a deterrent to herbivores like sea turtles and manatees. This is called intimidation behavior. Simply by swimming around, the sharks discourage herbivory, which is what ultimately helps keep the mangrove forests and sea grass communities going strong and these healthy communities provide habitat for a wide variety of marine organisms. Humans benefit because the mangroves can help prevent coastal erosion and flooding.
4. Optional activity: If you have access to student computers, it may be useful to provide students with another opportunity to interact with the shark story. The “Ecosystem Explorer” was inspired by content from the EARTH A New Wild series and includes a “Shark World” where students can explore the shark ecosystem through interactive, multi-media content. You can find the interactive content here: http://www.pbslearningmedia.org/resource/5aeed659-7f0b-417f-81d9-5f2e9c747644/ecosystem-explorer-earth-a-new-wild/. If time doesn’t permit, you could assign this as homework.
Part 1 Student Worksheet - Video Viewing Questions Answer Key
1. In the video, scientists are shown tagging different ocean predators. What kinds of data can scientists collect from the tags?
Answer: The tags data can tell scientists when are where the sharks are moving. Scientists can determine key migration routes, breeding grounds, and feeding grounds.
2. How does the tagging help with conservation?
Answer: It helps pinpoint the areas that might need to be protected. Tagging also shows movement and distribution patterns, as well as biological hot-spots, so that the culling of marine populations can be done with much more sustainable foresight.
3. What have researchers learned about lemon sharks through tagging?
Answer: Lemon shark females return to their birth places to give birth to new young.
4. What does the mangrove ecosystem provide for organisms?
Answer: It provides food and shelter for a variety of young marine organisms. An “underwater nursery.”
5. How do sharks maintain the mangrove ecosystem?
Sharks regulate feeding behavior of prey. Herbivores are less likely to eat as much vegetation when they are on the lookout for sharks.
6. List some examples of marine herbivores.
Answer: Manatees, sea turtles, some species of fish
7. How do the sharks help humans?
Answer: The mangroves decrease powerful waves that hit the shores during storms. Just by swimming in coastal waters, sharks keep the mangroves and sea grass areas healthy by preventing overgrazing. By protecting these areas, we are protecting shark nurseries and the sharks help protect the mangrove, which in turn protects our vulnerable coasts.
Section B: Threats to Sharks
1. The purpose of this part of the activity is for students to read more about the sharks around Bimini in the Bahamas and learn about some of the threats to the sharks there and elsewhere in the world. If you have time for students to read an article to learn more, they can do the following reading and white-boarding activity. If you want to introduce students to the threats that sharks face worldwide, but are short on time, you can show the video, “Collapse of Sharks” (3:05 minutes), which examines the demand for shark fins in the Far East and describes the resulting decrease in shark populations.
URL: http://www.pbslearningmedia.org/resource/nat08.living.eco.humeco.collapse/collapse-of-sharks/
2. Distribute copies of the three-page National Geographic article “Blue Waters of the Bahamas” by Jennifer S. Holland and have students read the article. They can do this in class or for homework to save class time.
3. After students have read the article, assign them to small groups of three to four.
4. Distribute white boards or large sheets of drawing paper to each group.
5. Read off the first question and give students two to three minutes to do a very simple illustration for this topic. Emphasize that it does not need to be a work of art – stick figures will do. There should be no text accompanying their drawings. The groups can talk through what should be drawn and elect a student to do the drawing or they can all share the task. If you have access to small whiteboards, give one to each group for their drawings. If not, use large sheets of paper, or have students do this in their notebooks in small groups. If you have access to a document camera, students can project their drawings. The purpose behind using drawing for this activity is for students to synthesize the information from the text and not to copy from the reading when answering a question.
6. Once the time is up, have all of the students hold up their drawings and have the whole class look around and see what was drawn. Have each group elect a speaker to explain their illustrations. By having students hold up their drawings, you can quickly assess how the students have interpreted the reading and other students can check their answers against the rest of the class. Students may have drawn different things and that will allow the class to see the different interpretations of the article as well as the similarities.
7. Repeat this process for every topic in the list below.
Topics for illustrations:
· According to this article, what are the biggest threats that lemon sharks face?
Drawings may include fishing, long-lining, finning, human development
· Why are mangroves being threatened in the Bahamas?
Drawings may include buildings, boats, marinas, casinos
· How would the depletion or removal of an apex predator, like the lemon shark affect the marine ecosystem.
Drawings may include sharks eating other fish that are eating algae on coral reefs.
8. After the rounds of drawings are complete, conduct a final discussion and ask the students to share ideas about how humans can help sharks and marine ecosystems.
Student answers may include managing the number of tourists and creating marine protected areas.
Other Resources for Part 1:
· Information on the biology of Lemon Sharks:
http://www.elasmo-research.org/education/ecology/estuaries-lemon.htm
· Shark facts and information on how The Nature Conservancy is working to project sharks:
http://www.nature.org/ourinitiatives/habitats/oceanscoasts/sharks.xml
Part 2: Track a Shark!
Grades: 6-10
Subject: Science
Purpose: The purpose of this activity is to give students a chance to investigate the life of a great white shark using real tracking data from an online source. Students will also analyze other data to determine the reasons behind shark migration.
Time: Two 45-minute class periods
Materials:
· Teacher – computer, internet, LCD projector
· Copies of student worksheet for Part 2 (located at the end of this document)
· Internet with access to http://www.ocearch.org/ website
· Computers (one per student is ideal for this activity, but you could also group students on computers)
Objectives:
The student will…
· Describe the movement of sharks using an online tracking tool.
· Analyze the movement of sharks based on tracking data, sea surface temperature, and other factors.
· Relate shark movements to the geography the East Coast of the U.S. and the sea floor of the Atlantic Ocean.
· Identify areas where sharks and humans may come into contact.
· List the threats to sharks and describe how tagging data can help shark conservation efforts.
· Evaluate information and create a statement to explain the reasons behind shark migration.
Next Generation Science Standards:
Disciplinary Core Ideas:
· LS2A Interdependent Relationships in Ecosystems
· LS2B Cycle of Matter and Energy Transfer in Ecosystems
· LS2C Ecosystem Dynamics, Functioning, and Resilience
· LS4D Biodiversity and Humans
Crosscutting Concepts:
· Patterns
· Cause and Effect
Science and Engineering Practices:
· Asking questions
· Analyzing and interpreting data
· Constructing explanations
· Engaging in argument from evidence
Performance Expectations:
Middle School
· MS-LS2-1. Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
· MS-LS2-2. Construct an explanation that predicts patterns of interactions among organisms across multiple ecosystems.
· MS-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.