Carrying Capacity and Algal Blooms

Engage students with this investigative phenomenon to investigate an algal bloom and its impact on the environment.

Grades 9-12 235 min Resource by:

What effect will different nutrient concentrations have on the carrying capacity of algal populations in vitro? Students will investigate growth in algae populations maintained in different concentrations of nutrient solution.

Learning Objectives

  • Collect algal population density data over time and use a modified logistic growth model to determine the intrinsic population growth rate and carrying capacity.
  • Describe the differences between exponential growth and logistic growth and argue from evidence that algal population growth is density dependent.
  • Use the mathematical model to predict population size at any given time and compare the prediction with experimental results.
  • Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales.
  • Use evidence to identify the factors that have the largest effect on the carrying capacity of an in vitro algal population.
  • Use mathematical reasoning to interpret population growth models and graphs from collected data.

An algal bloom scenario serves as the investigative phenomenon that students are tasked with explaining. To make sense of the phenomenon, students investigate growth in algae populations maintained in different concentrations of nutrient solution. Over the course of the investigation, students conduct experiments and analyze data to answer the driving question, “What effect will different nutrient concentrations have on the carrying capacity of algal populations?”

  • How do you use a Smartphone Spectroscopy Chamber to analyze solutions?
  • What effect will differences in nutrient concentration have on the carrying capacity of algal populations in vitro?

For Students

  • Have students investigate additional factors limiting the growth and carrying capacity of the algal population.
  • Have students collect data on the global human population.

For Teachers

  • Suggested vocabulary words are listed in bold in the Student Guide. Consider having students create a glossary in their notebooks.