Initial Publication Date: June 4, 2018

The Wetlands pcMEL

The Wetlands pcMEL asks students to consider different viewpoints on the uses of wetlands, a socio-scientific issue. Some people value what wetlands offer the local environment, such as habitats for all types of organisms and a place for floodwaters to collect away from where people live. Others perceive them as property to develop or as a breeding area for mosquitoes. The Wetlands pcMEL uses two different conceptual models of a socio-scientific issue that focus on value to society, as opposed to two different models of a scientific phenomenon.

Below are links to resources that will help students use the Wetlands pcMEL and learn more about the competing views of wetlands.


This article provides an introduction to the Wetlands pcMEL plus suggestions from classroom use including implementation advice, insights into the lines of evidence that challenge students' thinking, and the rationale for using MEL diagrams to address socio-scientific issues that focus on value to society.

Wetlands: Good or Bad? TES front page
Wetlands: Good or Bad? (Acrobat (PDF) 388kB Jun4 18)

Next Generation Science Standards Performance Expectations

HS-ESS3-5: Earth and Human Activity

  • Create a computational simulation to illustrate the relationship among the management of natural resources, the sustainability of human populations, and biodiversity.

HS-ESS3-4: Earth and Human Activity

  • Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.

The Models

Model A: Wetlands provide ecosystem services that contribute to human welfare and help sustain the biosphere.
Model B: Wetlands are a nuisance to humans and provide little overall environmental benefit.

Student Handouts

Lines of Evidence

Evidence #1: Wetlands play a role in the global cycles of carbon, nitrogen, and sulfur. Wetlands change these nutrients into different forms necessary to continue their global cycles.
Evidence #2: Flooding is a natural occurrence in low-lying areas and wetlands are places where floodwaters can collect.
Evidence #3: Wetlands contribute 70 percent of global atmospheric methane from natural sources.
Evidence #4: Many wetlands are located in rapidly developing areas of the country.

Student Handouts

Other Resources

This Plausibility Ranking Task (PRT), which may be completed prior to using any MELs, helps students to understand the role of evidence in supporting or refuting models.

Virtual MEL

The Google Drive folder below contains MEL resource documents in the Google formats. In order to maximize the flexibility of our activities, the MEL Project Team wanted to make more resources compatible with virtual settings. We have made our MEL scaffolds available in Google formats, so that they can be copied, modified, and uploaded more easily on a variety of platforms and devices. Please note that to access all the materials for each MEL scaffold, you will need a Google account. View the README file first.

Digital Resources

EPA Wetlands Site
This site from the EPA, Wetlands Protection and Restoration, helps individuals learn about wetlands, understand the science of wetlands, find out how the EPA, state, and tribal government efforts are protecting wetlands and how individuals can become involved in preserving this natural resource.