Numerous reports suggest an increase in white shark encounters* in the United States in recent years and the public is worried.
*Encounters include sightings and census estimates, as well as physical interactions between humans and sharks.
Begin to construct and explanation supported by evidence to determine the possible causes of recent increases in white shark encounters and whether past records like the fossil record may provide us with reliable information to give context.
This part of the lesson sequence introduces students to the anchoring phenomenon and then uses news reports of sharks as an investigative phenomenon: shark encounters have happened recently and seem to be increasing.
Click here for NGSS, CCSS (ELA and Math), California ELD, and EP&C standards.
This learning sequence is positioned at the beginning of the last instructional segment identified for California Middle School Integrated, grade 8, in the California Science Framework (essentially, the end of middle school). Important Disciplinary Core Idea (DCI) prior knowledge that students should bring to this learning sequence from grades 6–8 includes history of planet Earth (rock strata and the fossil record can be used as evidence to organize the relative occurrence of major historical events in Earth’s history, ESS1.C), growth and development (animals engage in behaviors that increase the odds of reproduction, LS1.B), information processing (each sense receptor responds to different inputs, transmitting them as signals that travel along nerve cells to the brain; the signals are then processed in the brain, resulting in immediate behavior or memories, MS-LS1-8), interdependent relationships in ecosystems (organisms and populations are dependent on their environmental interactions both with other living things and nonliving factors, LS2.A), ecosystems dynamics (ecosystem characteristics vary over time. Disruptions to any part of an ecosystem can lead to shifts in all of its populations. The completeness or integrity of an ecosystem’s biodiversity is often used as a measure of its health, LS2.C), natural selection (both natural and artificial selection result from certain traits giving some individuals an advantage in surviving and reproducing, leading to predominance of certain traits in a population, LS4.B), adaptation (species can change over time in response to changes in environmental conditions through adaptation by natural selection acting over generations. Traits that support successful survival and reproduction in the new environment become more common, LS4.C) and wave properties. As this is at the end of middle school, students should also bring a full breadth of understanding of the 6–8 grade band progressions for the Science and Engineering Practices (SEPs) and Crosscutting Concepts (CCCs).
This learning sequence primarily serves to help students to extend understanding of wave properties, deepen understanding of waves and information technologies, and begin to build an understanding of magnetic and electric fields (students will receive much more detailed instruction later in the instructional segment) with a subtle nature of science storyline focusing on the value of interpretation of data in science and its role in framing knowledge (science is a way of knowing, scientific knowledge is based on empirical evidence, scientific knowledge is open to revision in light of new evidence). Set in the context of tracking sharks, integration of life science (how we learn information from the fossil record) and Earth science (human impacts) helps students begin to build an understanding of the phenomenon of the possible increase in encounters with white sharks and subsequent public concern. It is recommended that students have prior instruction on wave properties (just wavelength, amplitude, and frequency) when they study astronomy-related DCIs earlier in the year, as this sequence will provide students the opportunity to see those properties play out with tracking devices. (It’s possible for this to be addressed in this sequence, but the authors felt that to do so in a way that fosters adequate student sensemaking would take even more time in an already long sequence and deviate too far from the anchoring phenomenon.)
As this is the end of middle school, students should be at middle school level proficiency for SEPs and CCCs, although this sequence will reinforce a few. Throughout the sequence, students will be prominently using many elements of Asking Questions and Defining Problems, Developing and Using Models, Analyzing and Interpreting Data, and an intentional scaffolding of Constructing Explanations and Designing Solutions throughout, which will ultimately lead to students Engaging in Argument from Evidence as they decide how to influence public perception of white sharks. Cause and Effect is the strongest CCC at play where all elements are used by students (with some elements of Patterns and Structure and Function).
This Engage lesson introduces students to the anchoring phenomenon of the learning sequence (Numerous reports suggest an increase in white shark encounters in the United States in recent years, and the public is worried.) and a real-world investigative phenomenon (Shark encounters have happened recently and seem to be increasing.) that they can investigate. Students use their prior knowledge to share their own ideas about sharks and deepen their ability to ask questions based on observations from text to consider how they can distinguish fact from fiction. Students build on their abilities to analyze and interpret data to provide evidence for a phenomenon by questioning the sufficiency of the data they find. They use patterns to identify cause and effect relationships that are used to begin constructing an explanation about whether or not there are really more shark encounters now than in the past, relying on cause and effect to help them identify that the phenomenon likely has more than one cause. Following this lesson, students will have an opportunity to answer their questions about whether or not the amount of shark encounters in recent history is different from the past and what historical data suggests by analyzing fossil evidence and fishers logs on white sharks.
This lesson is part of a series in the learning sequence that will culminate in students revising an idea over time, leading to engaging in argument from evidence about the causes of recent increases in the white shark population, with the goal of building public understanding and alleviating concerns.
Following this lesson, students will have an opportunity to answer their questions about whether or not the amount of shark encounters in recent history is different from the past and what historical data suggests by analyzing fossil evidence and fishers logs on white sharks.
Throughout the lesson, a flag () denotes formative assessment opportunities where you may change instruction in response to students’ level of understanding and making sense of phenomena.
90 minutes | Engage |
Ask questions about data supported by evidence to determine the possible causes of recent increases in white shark encounters and whether past records like the fossil record may provide us with reliable information to give context.
Throughout the entire learning sequence, articles, videos, and websites have been carefully chosen so as not to reveal information students will later discover, allowing them to develop ideas over time. This first lesson, especially, is designed to have references that provide incomplete information so students can better engage in SEPs and CCCs. If other references are preferred, review the entire learning sequence to get a sense of what students will be discovering over time before replacing.
To start the lesson, give students the CSULB Shark Lab press release, 8.1.H1: CSULB Shark Lab Reports Record Breaking White Shark Sightings. This article sets the stage for the investigative phenomenon: shark encounters have happened recently and seem to be increasing. For classes with little prior knowledge on white sharks, see the shark sighting video to set the context without revealing information students will learn later in the learning sequence. (Sunset Beach is near Seal Beach.)
Ask students to read the press release and record the following in their Science Notebook:
To move students deeper into the SEP, as they record questions facilitate them by asking groups and individual students the following questions:
After time for individual processing, invite students to share with their group a detail they thought was important or interesting; a question they have or something they want clarified or more information on; and a personal experience. Give time to let some excitement in the room build. Remind students to use 8.1.H2: Scientist Communication Survival Kit to facilitate group conversations. (Use of this tool is a differentiation strategy and a strategy to promote more equal talk among students.)
Students use other sources of information in an attempt to identify a cause for patterns observed. Divide each group in half to focus research in two different areas.
Question: What data do we have on white shark encounters?
A possible source for this is “Shark Attacks Hit All-Time High in 2015” (Clark 2016).
Question: What do we know about white shark life history over time?
Ask students to record the question in their Science Notebook and record what they are able to find out about shark life history.
Possible sources:
Students working on this question can be put into smaller groups to peruse each resource, and then share what they learn with those that read a different source. Students may need clarification on what is meant by life history. Ask them for ideas of what they think life history means. Confirm and add onto student ideas to help build a class definition. You may find a definition in your curricular resources that would be useful to students. In the absence of that, the characteristics of a species’ life history are often considered to include the following:
One way to differentiate instruction for students is to suggest topics for investigation of shark life history. For the highly engaged student, the topics of “response to change in environment” and “other social behaviors” will provide a more challenging exploration and synthesis of information. Consider providing additional guidance in navigating resources for students that struggle to identify relevant information and/or suggest using a graphic organizer to help with focusing on important information. This can include sentence frames for students needing language support.
Students consider possibilities to explain the following question:
Question: Are there really more shark encounters now than in the past?
Have students work in groups of four, creating the table below, 8.1.C1: Shark Encounter Claim Chart on chart paper. (Chart paper is recommended, as it can be added to over time throughout the learning sequence and allows groups to work collaboratively.) Students can go back to the resources used in Step 5, Gathering More Information, to look for evidence for the three claims below. Have students code information in the chart that reveals any pattern among the sources and possible causes for that pattern. Patterns could be interactions with humans or other species (like seals), reporting of encounters, fishing, etc.
Some students may need clarification for the components of an explanation:
Students are considering three plausible claims for an explanation at this time in the sequence as a mechanism to see which has the strongest evidence and reasoning over time. As a result, it’s likely that students will be engaging in argument from evidence as ideas are refined over time.
Facilitating group discussion by circulating the room and asking guiding questions can support students in this task. Examples of guiding questions include: “How does this help answer our question?” “What other evidence should you consider to support this explanation?” and “Is there another explanation that can account for this evidence?”
Once groups have worked collaboratively, ask students to attach 8.1.H3: My Shark Encounter Claim Chart in their Science Notebook to help keep a personal account of information. (Students will be adding information to this chart throughout the duration of the sequence.) Remind students to code any information revealing patterns and possible causes of patterns.
Some students may ask for clarification as to what is meant by “the past.” In the context of this lesson and beginning 8.1.C1: Shark Encounter Claim Chart, it’s probably useful to think of “the past” as the overall history we have established for sharks throughout time (geologic time, evolutionary history). In subsequent lessons (by Lesson 8.3: Fisher Logs), some students may choose to use the lens of more recent history (“the past” being the last 100 or 200 years), which is fine. “Time” is a construct and should be agreed upon by the students in the class and may change depending upon usefulness.
There is likely not enough space in 8.1.H3: My Shark Encounter Claim Chart for students to record the breadth of information they will need to record in the sequence. Offer sticky notes as a way to “extend the notebook space.”
Remind students that their overall objective will be to communicate with the public about white sharks in a way that addresses concerns and helps communities make informed decisions.
Challenge each group to think about additional information needed to address the question, “Are there really more white shark encounters now than in the past?” This starts with examining the quality of their current explanation.
Code evidence according to its strength:
Code reasoning according to its adequacy:
Once this coding is completed, asking groups to brainstorm how they could strengthen each explanation (hint: look for missing colors) by expanding their chart to include a fourth component: information needed to strengthen this explanation.
Example of modeling use:
Teacher:Let’s look at what is written in the green box and record ideas you have about how scientists use patterns in your Science Notebook. Think of a specific way you have used patterns before. (Wait a couple of minutes.) Take a moment to discuss with your group one thing you can share with the whole class about how you understand patterns and how you have used what you have learned. (Wait a couple of minutes.) Someone from Group A, please share what your group discussed.
Student:We said that patterns can help us find a cause for something. She shared that we used this last week when we were trying to make sense of the finch data and we looked for a pattern that could help us decide what two variables we could compare.
Teacher:Tell me more about the pattern you found and how it helped you find a cause.
Student:Well, we noticed that a lot of finches died during a certain time–that’s a pattern–and we noticed that all of the birds that survived that time had bigger beak depths; that’s another pattern.
Teacher:How did that help you find a cause?
Student:We remembered what we learned about beaks being able to only get some food types, so we thought that the cause of death of the birds with smaller beak depths could be that only some type of food might be available.
Teacher:Thanks for sharing. How about another group, can you please share what your group discussed?
(additional discussion)
Teacher:Ok, so we all have some experience working with the concept of Pattern. Let’s look at the questions on this page now. Thinking about what you just said, which of these questions seems to “fit” here–which one might help us with our thinking about strengthening an explanation?
Student:Under Increasing Sophistication, bullet 5 helps: “What patterns provide evidence for your explanation?”
Teacher:Tell me more.
Student:Well, my group noticed that a source from Florida and California said shark populations around the world are declining, so that’s a pattern in evidence.
Teacher:What else can you add? How does that pattern strengthen your explanation?
Student:Um, maybe with sufficiency in evidence.
Teacher:How so?
Student:Well, it’s more than one source saying the same thing, so that’s multiple pieces.
Teacher:Thanks for sharing your thinking. You provided a useful example of how to use the resource. Ok, let’s try another, but this time I’m going to throw down a challenge. Can you use something from “On-Target”? It’s our goal to work from there.
*dead silence*
Teacher:This is more challenging, isn’t it? What do you think is meant by “macroscopic patterns” in the first bullet? (Continue the conversation and ask students to clarify meaning. Encourage students to write on their page, adding personal notes about how they interpret each element/bullet.)
Teacher:Let’s try again. Do any of these help give us a way to think about strengthening your explanation? Discuss with your group; I’ll check back in with you in a couple of minutes.
Teacher:Ok, what did you discuss?
Student:My group thought the last bullet, “What cause and effect relationship(s) can you identify from the pattern” would work.
Teacher:Tell me more.
Student:Well, we had reports showing a pattern that shark populations around the world are declining, and we also noticed that there were reports showing a pattern that the rate of sharks being captured by humans is alarmingly high, so maybe a pattern of humans capturing sharks is causing their decline.
Teacher:So you have a pattern that helped you identify a cause and effect relationship. How does that help strengthen your explanation?
Student:Um, well, we are confused because we see it in two places. It strengthens evidence for the claim that there are more encounters because we capture a lot, but we wrote that the populations are declining in the fewer column.
Teacher:So, it sounds like your group needs to continue discussing this and make a decision about where this best fits or if we need it in both places for now until we can get more information. I’ll check on your group in a few minutes.
Teacher:What questions can I answer about how to use this resource?
After a few moments, encourage the students to use the resource independently, checking on groups as they start working.
For future use of 8.1.H4: Crosscutting Concepts for Middle School Students, each time students use a new crosscutting concept on the handout, use a similar discussion pattern–asking students to share what they understand about the crosscutting concept, how they have used it in the past, what questions they feel would help facilitate their thinking, and share examples of how to move over to the On-Target category to ensure students are engaging at the 6–8 level.
This resource can also be used as a rubric for assessing where students are on a continuum of understanding of the crosscutting concepts. Consider replacing column headers with 1-2-3. Students who are routinely using questions from Entry Level are a 1, those routinely using Increasing Sophistication are a 2, and those routinely using On-Target are a 3.
When researching white shark encounters and life history over time in an attempt to answer the question, “Are there really more shark encounters today than in the past”:
Students should realize that they need a context larger than the years identified in the websites visited. Encourage groups to discuss how they can build an accurate record of information on white sharks that have visited the coast of California in the past. Have students keep a record of their conversation in their Science Notebook. We cannot establish if the population we are seeing today is normal, increasing, or decreasing without a context for what the population has done over time (or compared to the past).
For groups that seem stuck, ask:
When some groups appear to be on-target (ideas emerge about looking for fossils and/or asking lifeguards, fisherman, scientists), bring the conversation back to the whole class, and lead a discussion that reveals the fossil record and fisher logbooks as plausible sources of information. (Both will be future lessons in the learning sequence.)
Build a class chart where each group contributes at least three things:
Ask students who need help with reading tasks to skim the article first, and identify any words for which they want clarification. Clarify the directions, then ask students to do a “group read” (have one person in the group read the article out loud), but encourage students to withhold group discussions until everyone has had a chance to do their own thinking and make notes in their Science Notebook first, then discuss with their group, and revise Science Notebook work accordingly.
By seating students in groups (groups of 4 work well) and encouraging regular conversation, students have time to interact more with content and naturally help those that need more support. Use of 8.1.H2: Scientist Communication Survival Kit, helps to make sure that students who don’t feel comfortable sharing (often because of language, literacy level, uncertainty of content knowledge, etc.) are prompted to do so in a supportive way.
Use of a sense-making Science Notebook supports student language development, conceptual development, and metacognition. Students should be prompted to use their Science Notebook for
Consider providing sentence frames for low literacy and second language learners. The use of graphic organizers can help struggling students manage Science Notebook work. To support students learning English, allow conversations and Science Notebook work to happen in the language that the student is most comfortable expressing understanding, and then encourage expression using simple English phrases (or more complex for students with increasing proficiency).
CBS Los Angeles. (2016, June 6). Shark Sightings Force Closure Of Stretch Of Sunset Beach. Retrieved from https://www.youtube.com/watch?v=rVQcRCcL-R4
Clark, A. (2016). Shark Attacks Hit an All-Time High in 2015, University of Florida News. Retrieved from http://news.ufl.edu/articles/2016/02/shark-attacks-hit-all-time-high-in-2015.php
CSULB Shark Lab. (2016). CSULB Shark Lab Reports Record Breaking White Shark Sightings Long Beach, CA.
Long, D. (2017). The Great White Shark, University of California Museum of Paleontology. Retrieved from http://www.ucmp.berkeley.edu/vertebrates/Doug/shark.html
Martins, C. and Knickle, C. (2017). Carcharodon carcharias, Florida Museum of Natural History, University of Florida. Retrieved from https://www.floridamuseum.ufl.edu/fish/discover/species-profiles/carcharodon-carcharias/
Monterey Bay Aquarium (2017). White Shark. Retrieved from https://www.montereybayaquarium.org/animals/animals-a-to-z/white-shark
National Science Teachers Association (2014). Crosscutting Concepts. Retrieved from http://ngss.nsta.org/CrosscuttingConceptsFull.aspx
National Science Teachers Association (2014). Science and Engineering Practices. Retrieved from http://ngss.nsta.org/PracticesFull.aspx
Wilson, C. and Patyten, M. (2015). White Shark Information. California Department of Fish and Wildlife. Retrieved from https://www.wildlife.ca.gov/Conservation/Marine/White-Shark#facts