Green Crabs: Great Marsh Invaders

Contributor
Alyssa Novak
Type Category
Instructional Materials
Types
Instructor Guide/Manual , Informative Text , Lesson/Lesson Plan , Map , Data , Graph
Note
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.

Reviews

Description

This Data Nugget lesson begins with a phenomenon: an introduced crab species is killing native plants in a marsh ecosystem. The invasive European green crab, introduced into the Great Marsh ecosystem on the North Shore of Massachusetts, uproots eelgrass, a native saltwater plant species, when the crab digs up the bottom looking for food and shelter. Scientists want to know how to reduce the harmful effects of the green crab on eelgrass. Data on the number of female and male green crabs found at 13 different locations in Essex Bay (an area within the Great Marsh) are provided to students with the driving question, “What locations in Essex Bay are the most promising for eelgrass restoration, based on the number of invasive green crabs?” The lesson involves calculating totals and “suitability score” (explained in the Data Nugget lesson), mapping data, making a claim, and providing evidence and reasoning to support the claim. Students are also asked to suggest further questions to investigate and to formulate a hypothesis to test one of their questions. A teacher guide is available by email request and a student activity sheet is provided.

Intended Audience

Educator and learner
Educational Level
  • Middle School
  • Grade 9
Language
English
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

HS-LS2-2 Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales.

Clarification Statement: Examples of mathematical representations include finding the average, determining trends, and using graphical comparisons of multiple sets of data.

Assessment Boundary: Assessment is limited to provided data.

This resource appears to be designed to build towards this performance expectation, though the resource developer has not explicitly stated so.

Comments about Including the Performance Expectation
Teachers may want to encourage students to pause and take some time to think, to closely examine the data, and to look at the locations of the green crab traps on the map prior to calculating crab totals and suitability scores. Using a think-pair-share format may help students to generate ideas about trends in the data and to ask questions, as well as providing teachers with a way to assess prior knowledge. Posting a list of students’ questions following this reflection and sharing time will help to engage students in the phenomenon, elicit prior learning, help students to anchor their claims in evidence, and make students’ thinking explicit for formative assessment.

Science and Engineering Practices

This resource appears to be designed to build towards this science and engineering practice, though the resource developer has not explicitly stated so.

Comments about Including the Science and Engineering Practice
This Data Nugget lesson is intended for students in ninth grade. The calculations include addition of two given data points and then using these totals to assign a “suitability score” for each green crab trap site based on prescribed ranges for each of 4 scores. Although the math is relatively simple, it may not be easy for students to use the results to make sense of the phenomenon of ecosystem function. Alternatively, students may move on too quickly to the next part of the Data Nugget lesson and not take time to make sense of the data. Teachers may want to encourage students to pause a second time after the calculations are done to relate the information to the map. Writing each calculated total (females, males, and/or the total of both females and males) alongside each trap location on the map may help students relate what they have calculated with how the green crabs are harming the marsh ecosystem. Having students articulate this relationship in writing would also serve as an authentic assessment. A teacher note provides additional information which teachers can share with students once they have fully related their data to the map. At this point, if students have more questions, they could be added to the class list, mentioned in the previous tips section. Additionally, students may be challenged to consider whether they think the “suitability score” is the best way to identify possible sites to restore eelgrass to the marsh ecosystem.

Disciplinary Core Ideas

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
The introduction within this Data Nugget lesson provides some background information to students on the behavior of the invasive green crab and how it harms the native eelgrass species. However, teachers may expect students to have further questions and should encourage students to do additional research. Generative questions such as these may help students to make sense of this phenomenon: 1) How does the number of crabs affect the eelgrass population? 2) Is it important if the eelgrass is absent or has a very low population in the marsh ecosystem? Why or why not? 3) Do you think eelgrass can grow again in the marsh ecosystem? Why or why not?

Crosscutting Concepts

This resource appears to be designed to build towards this crosscutting concept, though the resource developer has not explicitly stated so.

Comments about Including the Crosscutting Concept
This Data Nugget lesson is one example of the harm that an invasive species can do to an ecosystem. Connecting this example to other ecosystems, particularly ones near students’ homes or ecosystems more familiar to them, will help make this example more relevant and authentic to all students. The green crab/eelgrass relationship is just one within a complex ecosystem. Teachers may want to encourage students to learn more about the Great Marsh and to construct a food web in order to discuss how this system as a whole is affected by the invasive green crab. In this way, students can make better sense of “how things change and how they remain stable.” Teachers may want to ask questions such as, “What things may change when green crabs invade a marsh ecosystem?” or “What things may stay the same when green crabs invade a marsh ecosystem?” Questions such as these will make students’ thinking explicit and may also serve as one type of formative assessment.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This Data Nugget lesson is structured to elicit direct observable evidence of students’ three-dimensional learning as they make sense of an authentic phenomenon and real associated data. This lesson could be strengthened by providing ways to elicit student questions and prior knowledge. Suggestions are provided in the “Tips” sections of this review.

  • Instructional Supports: This Data Nugget lesson offers teachers strong instructional support. A teacher guide is available by email request and a printable student activity sheet is provided. The Teacher Guide includes both teacher notes, checks for understanding, and answer keys. The final questions within the Data Nugget lesson provide opportunities for extended activities. The website provides additional instructional support for differentiated instruction (http://datanuggets.org/adapting-data-nuggets-to-your-classroom/ ) and extension (http://datanuggets.org/before-using-nuggets/extensions/ ). Further professional development on how to use DataNuggets in the classroom is also provided on the website (http://datanuggets.org/resources/presentations-slides-posters/ )

  • Monitoring Student Progress: This Data Nugget lesson provides ways for teachers to observe evidence of students’ three-dimensional learning through the math calculations, mapping, constructing a claim, providing evidence for the claim, and providing reasoning to support the claim. In addition, students are asked to generate further questions for study, construct a possible hypothesis, and identify the dependent and independent variables for their hypothesis. The teacher guide provides formative assessment questions and possible student responses to help with scoring. Teachers are encouraged to use the provided suggestions in the tips sections to further monitor student progress.

  • Quality of Technological Interactivity: This is not an interactive, technology-based resource.