Biodiversity can be measured at many levels (e.g. gene, species, ecosystem). Species diversity is a major component of biodiversity and can contribute to ecosystem stability. Diversity measures such as species richness (the number of different species present) and evenness (the relative abundance of each species) are useful quantitative metrics for understanding how communities are structured. Diversity indices such as the Shannon index and the Pielou's evenness index incorporate both richness and evenness into a single measure of species diversity and can be useful for comparing biodiversity between sites and/or over time. In this module, students will analyze data from the Florida Keys Reef Visual Census (FKRVS), a long-term monitoring effort of key reef fish populations in the Florida Keys National Marine Sanctuary. Coral reefs support more species per unit area than any other marine environment (NOAA) and have significant economic and recreational value. Unfortunately, climate change, pollution, habitat destruction and disease have threatened many coral reefs and the communities that inhabit them. Students will calculate the species richness as well as the Shannon index and Pielou's evenness index across different years of data and between different reef types. Furthermore, students will explore how years with high frequencies of hurricanes impact these measures. The module culminates with students writing a summary finding of how reef types and hurricane frequency will impact the FKRVS in the future.
By the end of this module students will be able to:
- Explain and define species richness, Shannon diversity index, and evenness index
- Analyze a large data set, using a pivot table, to determine species richness, Shannon diversity index, and Pielou's evenness index
- Explore how hurricanes and different reef types impact reef fish abundance and diversity indices
- Communicate and summarize findings clearly and effectively using quantitative evidence
Context for Use
The module was designed to be used in an undergraduate Ecology course where students have learned about species diversity but could easily be adapted to be used in an introductory Environmental Science course. This module could also pair nicely with introductory lectures about biodiversity and/or conservation biology.
The entire module can be completed during a 3-hour lab period or two 75-minute lecture periods. If students have experience using pivot tables in Excel, it would be possible to complete the module in a 2-hour lab period or one 75-minute lecture period. The module assumes that students have used a spreadsheet before and have an understanding of how to use basic functions in Excel (e.g. "=count").
How Instructors Have Used This Module
Using Project EDDIE modules in Environmental Earth Science
Robin Collins, Champlain College
Instructors are always trying to find new and innovative ways for students to gain more confidence and familiarity with data analysis. No matter what level of student you are teaching, EDDIE modules are a great tool to enhance student quantitative reasoning. The modules are well organized, have clear learning objectives/materials and most important, they are fun!
Description and Teaching Materials
Quick overview of the activities in this module
- Activity A: Calculate the species richness, Pielou's evenness, and Shannon index for a given year of data from the Florida Keys Reef Visual Census (FKRVS)
- Activity B: Analyze and compare diversity measures to a different year of data that followed a hurricane intensive year
- Activity C: Investigate how benthic reef habitat and hurricane frequency influence biodiversity in the FL Keys and synthesize all of the data into a summary finding.
Workflow of this module:
- Have students read this brief summary of the FKRVS before coming to class
- Give students their handout when they arrive to class
- Instructor gives brief PowerPoint presentation and provides background information on the biodiversity metrics the students will be calculating
- Instructor walks through a simple example in Excel with the students using a smaller data set. The instructor excel file is included in the teaching materials and students have the same example in the introduction to their learning module.
- Students can then work through the module activities.
- Instructor PowerPoint (PowerPoint 2007 (.pptx) 6.2MB Aug2 22)
Teaching Notes and Tips
- Working as a group on the simple instructor example was helpful for students to gain confidence in the Excel formulas that they needed to use to calculate the biodiversity metrics.
- Building in time for reflection after each Activity was helpful. For example, after students completed Activity A (where they should all obtain the same answers), having students discuss with their bench mates and then having a short classroom discussion about how to interpret the results was helpful.
- After students complete Activity C, looking at how hurricane frequency and reef type impact the biodiversity measures, it was helpful to give students an opportunity to share their findings with the class. Depending on the amount of time that was allocated to this module, you could also have students work together to determine which reef types are most vulnerable to climate change and deserve priority conservation. This FL DEP Technical Report would be a good resource for students to have a more evidence-based discussion about the vulnerability of different reef types to climate change.
Also, see author's instructor story.
Activity A: Students determine abundance, species richness, Shannon index and Pielou's evenness index for one year of data from the Florida Keys.
Activity B: Students choose a different year of data (following hurricane intensive years) and determine abundance, species richness, Shannon index and Pielou's evenness index. Students then compare and write a short paragraph on how the two years compare for the values they calculated.
Activity C: Students choose two habitat strata to investigate for each year of data they examined. Students provide a written summary of how the diversity measures changed over time and how the different strata differed in species diversity and were impacted by hurricanes. Students can then engage in a classroom discussion on their work could prioritize future conservation efforts and provide quantitative evidence to support their recommendation.
References and Resources
Student Reading - Provides a short background on the FKRVS - History, duration, purpose and sampling methods. There is an embedded video that describes the reef visual census sampling method. https://myfwc.com/research/saltwater/reef-fish/monitoring/fim-fl-keys-visual-sampling/
Spreadsheet tutorial - Provides an excellent introduction to spreadsheets, if students are new to working with Excel. https://www.biointeractive.org/classroom-resources/spreadsheet-tutorial-1-formulae-functions-and-averages
Florida DEP Technical Report on coral reef resilience to climate change - Provides relevant background information and data for students to have an evidence-based discussion on which reef types are most vulnerable to climate change. https://floridadep.gov/sites/default/files/DEP_Reef%20resilience%20in%20the%20FRT_Maynard%20et%20al._FINAL%2006.30_0.pdf
Dataset protocol - Brandt, M.E., N. Zurcher, A. Acosta, J.S. Ault, J.A. Bohnsack, M.W. Feeley, D.E. Harper, J.H. Hunt, T. Kellison, D.B. McClellan, M.E. Patterson, and S.G. Smith. 2009. A cooperative multi-agency reef fish monitoring protocol for the Florida Keys coral reef ecosystem. Natural Resource Report NPS/SFCN/NRR-2009/150. National Park Service, Fort Collins, Colorado