Practical Skills Day # 7. Lesson plan

Diving into Marine Biodiversity: Understanding and Interpreting Simpson’s Index of Diversity

Marine ecosystems are teeming with diverse life forms, each playing a crucial role in maintaining the health and balance of our oceans. Measuring this biodiversity is essential for understanding the complexity and resilience of marine habitats. One powerful tool used by marine scientists to quantify biodiversity is Simpson’s Index of Diversity. In this blog post, we will explore how Simpson’s Index is used to calculate marine biodiversity and how to interpret the results to gain meaningful insights into the richness and evenness of marine life.

Lesson Outline

• How Ocean Acidification Affects Marine Organisms-cont. (15 minutes)
  • Students will conduct observations, pH measurement and record shell weight for control and experimental group.
  • Students will record all data and observations.

• Lecture/Notes (PPT – slides 36 – 41)
  • this lesson covers the concept of calculating marine biodiversity using Simpson’s index of diversity.
  • Simpson’s Index of Diversity (D) is a measure used to quantify the biodiversity of a habitat. It takes into account both the number of species present (richness) and the abundance of each species (evenness).
  • A higher value of D (closer to 1) suggests a high level of biodiversity, indicating both a large number of different species (richness) and a balanced distribution of individuals among those species (evenness). High biodiversity is often associated with a healthy, resilient ecosystem that can better withstand environmental stressors such as pollution, climate change, and habitat destruction.
  • A lower value of D (closer to 0) indicates lower biodiversity, suggesting either fewer species or a dominance of one or a few species over others. Low biodiversity may signal an ecosystem under stress, where certain species dominate due to factors like overfishing, pollution, or invasive species. Below are slides 36 and 37 of the PPT.

• Use Student Guided Notes – This year, I’m using Version B Guided Notes with my students, as I’ve noticed they benefit from having more structured support during class.
  • It features fill-in-the-blank prompts for key vocabulary and concepts, making notetaking faster and more accessible, especially for English language learners or those with processing difficulties.
• Guided Practice
  • Divide students into small groups and provide each group with a different set of species data from various marine habitats (see examples below)
  • Each group calculates the Simpson’s Index of Diversity for their data set.
  • Groups discuss their findings and what the values indicate about their habitats’ biodiversity.

Example of ecosystem	Species Data	Answer Key
Example 1: Coral Reef	Species A: 10 individuals Species B: 15 individuals Species C: 5 individuals Species D: 20 individuals	N = 50 Calculate (n/N)2 for each species: Species A: 0.04 Species B: 0.09 Species C: 0.01 Species D: 0.16 Sum these values: 0.04+0.09+0.01+0.16=0.30 Apply the formula: D=1−0.30 D=0.70 Simpson’s Index of Diversity: 0.70
Example 2: Kelp Forest	Species A: 30 individuals Species B: 25 individuals Species C: 15 individuals Species D: 10 individuals Species E: 20 individuals	N = 100 Calculate (n/N)2 for each species: Species A: 0.09 Species B: 0.06 Species C: 0.02 Species D: 0.01 Species E: 0.04 Sum these values: 0.09+0.06+0.02+0.01+0.04=0.22 Apply the formula: D=1−0.22 D = 0.77 Simpson’s Index of Diversity: 0.77
Example 3: Mangrove Swamp	Species A: 50 individuals Species B: 10 individuals Species C: 5 individuals Species D: 5 individuals Species E: 30 individuals	N = 100 Calculate (n/N)2 for each species: Species A: 0.25 Species B: 0.01 Species C: 0.002 Species D: 0.002 Species E: 0.09 Sum these values: 0.25+0.01+0.002+0.002+0.09=0.354 Apply the formula: D=1−0.354 D=0.644 Simpson’s Index of Diversity: 0.644
Example 4: Rocky Shore	Species A: 40 individuals Species B: 10 individuals Species C: 25 individuals Species D: 15 individuals	N = 90 Calculate (n/N)2 for each species: Species A: 0.198 Species B: 0.012 Species C: 0.077 Species D: 0.028 Sum these values: 0.198+0.012+0.077+0.028=0.315 Apply the formula: D=1−0.315 D=0.685 Simpson’s Index of Diversity: 0.685

• Independent Practice: Simpson’s Index -simulation
  • Provide each student with a copy of Simpson’s Index -simulation
  • Each student calculates the Simpson’s Index of Diversity.
  • Students discuss their findings and what the values indicate about their habitats’ biodiversity.

Practice questions AICE style – with Answer Key

Homework – high level/flipped classroom

• Version A – For High-Level Students:
  Ideal for independent or advanced learners, this version requires students to copy all notes by hand as homework before class. This flipped-learning approach helps students come to class prepared, freeing up time for application activities, discussions, and AICE-style practice questions.
• For this assignment have students fill in the blanks using the PPT Presentation. The Guided Notes can be found HERE.

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Simpson’s Index of Diversity is a valuable tool for marine scientists to quantify and understand the biodiversity of marine ecosystems. By calculating and interpreting this index, students can gain insights into the richness and evenness of species in a given habitat, assess the health and resilience of ecosystems, and inform conservation strategies. Teaching students to use and interpret Simpson’s Index not only enhances their scientific skills but also fosters a deeper appreciation for the complexity and importance of marine biodiversity. Through hands-on learning and real-world applications, we can inspire the next generation of marine scientists to protect and preserve our oceans’ precious ecosystems.