Lesson 2 – GSL case study introduction

Course:  Life Science, Integrated Science, STEM

Unit:  Ecological Networks Part 1- Network interactions


See Standards Addressed for all NGSS and WA State (Science, Math and Literacy).  In addition to the aligned objectives linked above, for this lesson, here is a breakdown of:

What Students Learn:

  • Observations lead to hypotheses and experimental design.
  • An ecological disturbance in a single abiotic or biotic factor could affect an entire ecosystem.
  • Natural events and human activities affect the Earth’s capacity to sustain biological diversity.

What Students Do:

  • Students use scientific thinking to consider how a disruption in an ecosystem has affected that network.
  • Students design a scientific investigation to test how salinity affects halobacteria.









The students will be presented with a real life example of an event that affected the Great Salt Lake ecosystem - the building of a causeway. Based on observations of this phenomenon, students will generate hypotheses about factors affecting the growth of one prominent organism in this ecosystem,Halobacterium. They will then think about how they could design an experiment to test their hypotheses. This will lead to the implementation of an experiment testing the effect of salinity on the growth of Halobacterium.

Teacher Background InformationTeacher Background Information


Please note: There are VERY IMPORTANT steps that need to be taken for lab preparation. Please prepare the Halobacterium culture AT LEAST 4 days prior to beginning the lab with students. The directions for this are located in Lesson 4- Conducting halo salinity experiment in the section entitled, “Preparation of the Culture”.