Part I

Engage (30 minutes)

Return to the Anchoring Phenomenon

Reintroduce students to the article used at the beginning of the learning sequence, 8.1.H1: CSULB Shark Lab Reports Record Breaking White Shark Sightings (from Lesson 8.1: Shark Encounters). (Consider also finding recent news articles for your area that report on similar information on White Sharks that students could review.)

1. Ask groups to build a T-chart in their Science Notebook. In one column of the T-chart, they should recall/look at their original thoughts about the article. In the other column, list what they think today, considering what they now know about white sharks.
2. Ask students to reference the classroom chart 8.1.C1: Shark Encounter Claim Chart and their notes on 8.1.H3: My Shark Encounter Claim Chart, which they began building in Lesson 8.1: Shark Encounters. They should use the body of work from the learning sequence in their Science Notebook and discuss as a group what changes they would make given what they know today. (Encourage students to make actual changes.) Give students time to discuss and update. Following are some suggestions to help with updating reasoning.
   1. Direct students to use the On-Target column of 8.1.H4: Crosscutting Concepts for Middle School Students for three dominant crosscutting concepts prominent in the learning sequence: patterns, cause and effect, and a third crosscutting concept used in the sequence (either stability and change; scale, proportion, and quantity; structure and function; energy and matter; or systems and system models) to guide reasoning statements. Statements should be coded according to a crosscutting concept.
   2. Ask students to consider what information is missing from their chart. Do they have sufficient and appropriate evidence? Identify what is missing/what is needed to have a complete explanation.
   3. Ask students to compare 8.1.C1: Shark Encounter Claim Chart posted in the class and updated throughout the sequence to the one they built in their Science Notebook (8.1.H3: My Shark Encounter Claim Chart). Direct students to look closely at their reasoning statements; these should have something related to cause. Ask them to use 8.1.H4: Crosscutting Concepts for Middle School Students (from Lesson 8.1: Shark Encounters) to be specific about what element of cause and effect (or other crosscutting concept) is in their reasoning statement.
3. Have a class discussion about where student thinking is now by asking students to share some aha moments they got from completing the T-chart (in Step 1a above) and updating the Shark Encounters Claim Chart (either the classroom chart or their individual chart). Probe students to elaborate on their thinking by asking open ended questions, such as “Why do you think so?” and “Tell me more.” Ask students to share some wonderings they have.

Part II

Elaborate I (45 minutes)

What Do We Know in California?

1. At this point in the sequence, students may be conflicted over which claim has the most evidence; they will need more information to establish that there is an increase in white shark encounters, and need more information to have evidence that is reliable (data) and fully develop reasoning. If some groups are holding on to ideas that the population is remaining the same or decreasing, it’s ok to acknowledge that there isn’t full agreement “among scientists” in the room; we all need data to inform our explanation.
2. Project 8.9.R1: Frequency and Distribution of Reported White Shark Captures for the class to review. Have a brief class discussion to highlight what students remember about this figure (initially reviewed in Lesson 8.3: Fisher Logs). Ask students to ignore “unknown” and identify/estimate what age class of white sharks were caught the most often. (Students should identify YOY or young-of-the-year, with juveniles being a close second.) Confirm that students recognize that the most frequently caught white sharks are not the adults, but rather the “babies.” Ask students to recall information they researched in Lesson 8.4: REMUS about the differences between the babies and adults, specifically in how they hunt for food; what they eat will be an important “punch-line” to recall in the next lesson.
3. Let students know you’ve managed to track down more data for them to help resolve narrowing down to one claim, and that they will be using a tool that will help with interpretation as the data comes from a primary source (directly from a scientist). Distribute copies of 8.9.H1: I Can Use the Identify and Interpret (I²) Strategy and give a brief overview. Project 8.9.G1: Locations of White Shark Captures in Southern California by Age Class: YOY and ask students to take a few minutes to just look at the figure and see what sense they can make of it. Before answering any student questions or allowing discussion, direct students to use the I² strategy on 8.9.H1: I Can Use the Identify and Interpret (I²) Strategy for help, and record the following in their Science Notebook:
   • Three “What I see” comments
   • Two “What it means” comments
     1. For students who finish early, encourage them to include crosscutting concept thinking here. For example, an increase in white shark captures in the late 2000s is correlated with the Monterey Bay White Shark Program incentivizing fishers to report catches (cause and effect).

   Consider allowing students who need literacy support to work in pairs.

4. After allowing a few minutes to attempt on their own, ask the class for questions that are preventing them from making comments on the figure, and address those questions (not confirming work, just answering questions preventing them from engaging). Encourage students to try again, and give a couple more minutes for students to generate comments about the figure.
5. After allowing enough time for students to try on their own, invite students to share some “What I see” and “What it means” comments and verify those that are accurate. For any that seem off target, ask probing questions (such as, “Can you tell me more?” or “What did you see that led you to think this?”) to help redirect thinking and support student sensemaking of phenomena.
6. Inform groups that they will now split up into expert groups. Each expert group will be in charge of more figures from the same chapter.
   1. Assign students in each group into the following expert groups (large expert groups can be subdivided into smaller expert groups) and distribute the group handouts as outlined below.
      • Student A: 8.9.G1: Locations of White Shark Captures in Southern California by Age Class
      • Student B: 8.9.G2: White Shark Captures by Season in Southern California
      • Student C: 8.9.G3: White Shark Capture Methods and Captures per Month
      • Student D: 8.9.G4: YOY White Shark Captures Before and After Nearshore-Gillnet Ban
   2. Have students rearrange themselves into their expert groups. The job of the expert group is to do the same thing for all figures they are given:
      1. Generate three “What I see” comments.
      2. Generate two “What it means” comments. (Encourage students to apply crosscutting concept thinking here; see example below.)
      3. If time permits,
         1. encourage students to include On-Target crosscutting concept thinking. For example, an increase in white shark captures in the late 2000s is correlated with the Monterey Bay White Shark Program incentivizing fishers to report catches (cause and effect); and
         2. encourage students to generate a caption however, note that this will not necessarily be equitable across all groups as some figures provide more information than others.

TEACHER NOTE

For differentiation, consider the figures you give to students when jigsawing. For example, 8.9.G3: White Shark Capture Methods and Captures per Month may be more approachable to students, as a bar-style graph tends to be familiar; 8.9.G1: Locations of White Shark Captures in Southern California by Age Class and 8.9.G2: White Shark Captures by Season in Southern California are a bit more sophisticated (due to their map coding perspective) but still accessible to most students using the I² strategy. The figures shown on 8.9.G4: YOY White Shark Captures Before and After Nearshore-Gillnet Ban are good for students who would benefit from interpreting a figure that is more challenging, as each represents multiple types of information in one figure.

7. When all expert groups are finished, have experts return to their home group and share what they learned. Ask each group to update their 8.1.H3: My Shark Encounter Claim Chart (and Science Notebook) with new information and code according to crosscutting concept–patterns, cause and effect, and a third of their choice (stability and change; scale, proportion, and quantity; structure and function; energy and matter; or systems and system models) where they do. In addition, they should include a specific element of the crosscutting concept in their reasoning statement. It is at your discretion whether or not to update the class chart (as individual charts now show differences as students do more independent sensemaking).

Part III

Explain (75 minutes)

Group Explanation for What We Know in California

1. Ask each group to take their findings and generate a group explanation to address the question: Are there really more shark encounters now than in the past? Do not provide claim, evidence, reasoning (CER) scaffolding. Direct groups to use the most compelling evidence they have from their chart and then construct their explanation.
2. Before students work, verify a few key points:
   1. Verify that students understand that a population increase (more white sharks in the water) is correlated with more encounters with sharks. We use the word correlated in science the same way we use linear relationship in math. One doesn’t necessarily cause the other, but there is a relationship in the pattern observed between the two. Ask students to make sure this is accurately represented in their explanation and to make edits if necessary.
   2. Verify that students understand that numerical data is the most compelling evidence in science and meets our criteria for “appropriate evidence” (scientifically relevant). The evidence students identify must include numerical data. Some students may need help turning numerical data into a sentence; make a sentence frame available to students who need it.

TEACHER NOTE

No CER scaffolding is given to students in creating their group explanation as this is building from prior lessons that provided scaffolding. Monitor individual students to see if a scaffold is needed.

Checking in with Another Scientist

1. Now that they have a robust explanation, inform students that one of the things scientists do is read what other scientists, who study similar things, have done. Ask students why this is important in science and facilitate a brief discussion.

TEACHER NOTE

This discussion is a useful opportunity to bring up the concept that science is a way of knowing; that science is a body of knowledge and that it’s cumulative (knowledge often comes from more than one source); and that scientific investigations use a variety of methods (in this case, historical fishers data along with data obtained from tracking technology). When studies have complimentary findings and explanations, this increases the strength, or likelihood, that we can be confident in those explanations. When findings and explanations are contradictory, we are less confident in the results. (Notice the absence of the word prove; scientific explanations are probabilistic, not absolute. Scientific explanations can be disproved, but not proved because explanations are not the same thing as observations.)

2. Does their interpretation support yours? Distribute 8.9.H2: Historic Fishery Interactions with White Sharks in the Southern California Bight: Abstract. Let students know that we have done a lot of our own work, and this is their chance to compare their thinking to that of another scientist. They are about to read the abstract from the same paper as the figures they have been studying. The abstract is the brief, one-paragraph, summary of the study. Ask groups to read the abstract together (students in the group can take turns reading sentences aloud) and to do the following (intended as literacy support for all students):
   1. Circle parts where they don’t know what a word or set of words means. (Let them know it’s ok to signal you for help.)
   2. Underline parts they think are important, especially the claim made in the abstract.
   3. Highlight one sentence from the abstract that is similar or different from their thinking (and code for similar or different).
   4. Be ready to discuss with the class.
3. Ask groups to share their thinking with the class:
   • How does their explanation compare to that of Dr. Lowe and group?
   • What do they notice about the two explanations?
   • What can they infer if two scientists come to the same conclusion?

   Following the discussion, ask groups to compare their explanation to this abstract and invite students to make at least one update to their explanation based on what they see in this abstract.

4. As they did in Lesson 8.1: Shark Encounters, ask students to code evidence in their explanation according to the strength of the evidence, as this type of coding will naturally differentiate for different learners. (Students who have a strong understanding of the Performance Expectation should be able to code multiple pieces of evidence, cite support for this within the text, and reflect on how it addresses the phenomenon in their reasoning. The task of color coding provides a visual structure for students who would struggle with the complexity of the task.) Remind students how they coded evidence in Lesson 8.1:
   • Underline/highlight appropriate evidence (scientifically relevant) in color #1.
   • Underline/highlight sufficient evidence (multiple pieces) in color #2.
5. Ask students to code reasoning according to adequacy of the reasoning:
   • Underline/highlight reasoning that explains why the evidence supports the claim in color #3.
   • Underline/highlight reasoning that includes science ideas in color #4.

TEACHER NOTE

The intent of the Next Generation Science Standards and Common Core State Standards is that students work with and read complex text. It’s appropriate to begin exposing middle school students (especially 8th graders) to primary literature. In this case, students are asked to read one paragraph on a topic they have spent a lot of time investigating. The content should be familiar enough to students to allow them to access some meaning. Student interest should be high enough at this stage that even if the reading is beyond skill level, they should be able to engage. The supports provided (selection of a small amount of text, collaborative discussion, annotation and interaction with the text, and request to compare with personal thinking) are designed to help. Some students may still struggle; a little encouragement from you and some extra support when needed will go a long way. For students who read well-below grade-level, allow for partner support and/or read-aloud.

California White Sharks: A Human Impact Success Story

1. Engage students in a conversation about the role humans have played in the increase in the white shark population, referring back to what they have learned both here and in Lesson 8.1: Shark Encounters, and Lesson 8.3: Fisher Logs. Encourage students to use their Science Notebook to help them recall information. As students review and share, emphasize important key points that should emerge:
   1. As our human population grew, so did the demand for seafood.
   2. This resulted in advances in fishing technology that could allow fishers to be more efficient in their work (specifically, gillnets that could catch large amounts of fish at a time) to keep up with the demand for seafood.
   3. Fish reproduction couldn’t keep up with the demand, and the dramatic decline in fish populations as a result prompted legislation to regulate these fisheries and ban nearshore gillnetting.
   4. This led to the recovery of the white shark population, in part because the primary source of food for YOY and juvenile white sharks is fish (the same fish being protected) and because the very same YOY and juveniles that use shallow Southern California coastal waters as their nursery (the area that was once heavily fished) didn’t become accidental bycatch and drown (a small detail, but white sharks must constantly keep swimming to ram water over their gills in order to get oxygen; if stuck in a net, they do not get enough oxygen).
   5. This is perhaps the single greatest recovery of a vulnerable, and ecologically critical, species in California.
2. For students who are struggling with this information, help them visualize this information by asking them to construct a timeline (approximate) or use some other way to document a sequence of events from the decline to the recovery of white sharks, labeling On-Target cause and effect components. Students can team up and use whiteboards to strategize this together, with final work going in individual student notebooks.
3. Ask students to consider any revisions to their explanation in light of this information.
4. As students have discussion about their timeline and needed revisions, remind students to back up statements with evidence and scientific reasoning.

Part IV

Elaborate II (60 minutes)

A New Scenario

1. Our studies have largely focused on California, but our anchoring phenomenon alluded to an increase in encounters in the United States. Students may recall from Lesson 8.1: Shark Encounters that there is another population of white sharks on the East Coast of the United States, with news reports also reporting an increase in encounters. To help students explore this, divide the class into three large groups and give a few minutes to use prior knowledge and/or search the Internet for the following information:
   • Group A: How would you describe the physical conditions in the northwest Atlantic compared to the northeast Pacific? (You may need to brainstorm what is meant by physical conditions: weather patterns, water temperature, coastline shape, etc., for students who struggle with this.) If different, are there any locations where they are more similar?
   • Group B: Do you find similar trends with respect to the human population (specifically, human population growth) in the northwest Atlantic compared to the northeast Pacific?
   • Group C: What is the story of fisheries in the northwest Atlantic compared to the northeast Pacific? (What has happened to fisheries over the last several decades?)

   Students need only approximate answers; this doesn’t need to be a big research effort, so limit the time. To help, encourage groups to elect a facilitator that can quickly organize their group on how to divide and conquer their research effort–what aspect will each student focus on (this can be documented on white boards). Support their effort by suggesting key words that would be useful when searching. Have students record information in their Science Notebook; give them flexibility in the format (i.e., use tables, flow charts, etc., as preferred).

2. After researching, assemble students back in their home groups and give them a few minutes to collaborate and share their findings; then ask each group facilitator to report out to the class. Given this information, and what students understand about white sharks off the coast of California, ask groups to consider the following:

   News reports over the past couple of years indicate an increase in white shark encounters along the East Coast of the United States.

   1. Make a prediction, including rationale, about the Atlantic population of white sharks:
      • What patterns have emerged over the past few decades?
      • What type of spatial distribution can we expect (patterns in shark movements)?
      • What different age classes of white sharks will we find and why (cause and effect)?
      • What time of year will encounters be most frequent and why (cause and effect)?
   2. What is the ideal tracking device that you would use to study the members of the Atlantic white shark population?

   Groups should discuss and document ideas in their Science Notebook. This is intended to be a quick exercise, so limit the time.

Verify Predictions

1. Give students the opportunity to verify their predictions by skimming the following primary source article, 8.9.H3: Seasonal Distribution and Historic Trends in Abundance of White Sharks. Either distribute a copy to students or allow them to access it online at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0099240
   • Direct students to look for figures that might support or refute their predictions. They should note the figure number in their Science Notebook and note if the figure supports or refutes their predictions and why.

   TEACHER NOTE

   Students spent an extensive amount of time earlier in this lesson critically reviewing and making sense of figures from a different source. This resource closely parallels that study and should allow students the ability to find relevant figures to address their predictions. Rather than curating the resource for students, the entire paper is given, introducing students to a scientific research article. (You will likely find a few interested students reading some of the text for more information or to establish context.) Monitor struggling students to help guide them to a figure they can interpret. Monitor students to make sure they are using the I² strategy: identifying “what I see” and interpreting “what it means,” redirect when they are not using that strategy. Encourage students to include CCC thinking. For example, Figure 3 shows a higher density of white sharks in the spring and summer months and shows them being further north in the summer than in the spring. This could be the effect of young white sharks coming further north because coastal waters are warmer and there is a cause and effect relationship between water temperature and where YOY and juvenile sharks live; at this size they are unable to regulate their body temperature as adults do.

   • After independent work, allow students to collaborate as groups, ending with a class discussion on which figures were the most valuable, which supported or refuted predictions and why, and “what the heck was that?!?” (likely figures that involved statistical analysis). Spend more time discussing those that were valuable for supporting or refuting predictions and ensure that all students understand how figures could refute predictions (a challenging idea for some students).

Global Shark Tracker (OPTIONAL)

Motivated students who want to take a deep dive and follow a shark in real time can choose a white shark to follow on the Ocearch website http://www.ocearch.org/. Ocearch tracks different types of sharks in real time, which students can filter based on tracking activity (how recently a shark’s tag has been pinged), species, sex, stage of life, and location. Use 8.9.R2: Global Shark Tracker with students who wish to continue on their shark journey.

What Have We Learned? Final Explanations

1. Probe student thinking. Recall the effect of entangling nets before the gillnet ban– fish populations declined, and YOY and juvenile white sharks made up the majority of sharks that were bycatch. Ask students to discuss the following with their group to help remind them of some critical learnings that will inform their explanation:
   1. Why did young sharks make up the majority of captures?

      Expected student responses:

      • Younger white sharks stay close to shore.
      • Fishermen were looking for smaller fish.
   2. When gillnets/entangling nets were banned (1994), what did it do to the fish population?

      Expected student responses:

      • The population gradually increased.
      • Fewer fish were getting caught in gillnets.
   3. How did an increase in the fish population affect younger white sharks?

      Expected student responses:

      • The fish population increased within the 3 mile limit of the gillnet ban.
      • An increasing fish population meant more fish for sharks to eat.
      • Young sharks swim mostly close to shore because the fish they eat swim in shallow waters.
   4. Predict what would happen to the white shark population over time with the long-term effects of the ban on nearshore gillnets.

      Expected student response:

      • White shark populations should increase over time due to gillnet bans, which means we should have more encounters with sharks close to shore.
2. Ask students to consider the discussion and make final edits on their explanations. Remind students to frame the explanation through the lens of the On-Target column of a crosscutting concept. Interact with student work using sticky note feedback as described in Lesson 8.1: Shark Encounters. At your discretion, this individual explanation can be written outside of the Science Notebook and used as a summative assessment.

As a scaffold, students can visually depict this “chain of reasoning” and use it to inform changes to their final explanations.

TEACHER NOTE

Making sure they grasp the big “punchline” here will be useful for students in the final lesson of this sequence: that the sharks we encounter close to shore are YOY and juveniles, a population once on a dangerous decline due to human demand for fish, but benefitted by legislation over the last 30+ years intended to protect the fish (that they eat). Students might need help connecting all of the information. They would have researched that female white sharks take, on average, 33 years to reach sexual maturity; the YOY and juveniles we are seeing today are the offspring of those that were protected by the gillnet ban in 1994. Students should be clearly discussing the role humans have had in this. Further, the notion that a pattern observed on one coast can predict that of another adds strength to explanations that students build.

As students embed their responses into their explanations, ask them to recall features that make reasoning statements strong. There is no rubric for this lesson (because the work here shapes into a final work product in Lesson 8.10), but the sticky note feedback is an opportunity for you to help shape student work into that which is grade-level appropriate, setting students up for success in Lesson Lesson 8.10: White Shark Public Service Announcement.

Resources