Lab 8 - Aquatic Ecology: Biotic Components

Continuing the Aquatic Ecology lab is the biotic components lab, which is another outdoor lab at Lake Wells on campus. The lab involved a sampling of organisms at the lake and then identifying them back in the classroom. By seeing the different types of organisms that live and interact, the students are able to see how ecosystems work with a local example.

To gain this understanding, the teaching assistant first taught about what ecosystems are and the different trophic levels that exist within them. The class then proceeded to the lake with buckets and sample bottles and used small nets and waders to collect plankton, macroinvertebrates, and plants. By having them collect their own samples, the concepts of how these organisms exist in an ecosystem is seen first hand, such as how a student will collect dragonfly larvae, and then think of how it got there and what it does to survive.

Identification of the samples was then started back in the classroom. All benches had field guidebooks for students to look up organisms. It is also interesting to note that microscopy had a tie in into this lab. Students utilized simple and compound microscopes to look at macroinvertebrates and plankton. They also used Lugol’s solution and glass slides to make their own wet mounts of plankton. Most of the students were able to remember how to use the microscopes, and this opportunity helped refresh the knowledge in their heads.

This turned out to be a great follow up lab for the biotic components. Now that students know both components, they can understand the interaction between water quality and the organisms who inhabit the water, as well as what balance between the two is needed for a healthy ecosystem. The only thing that could have helped this lab more is providing other ecosystem organisms to compare and contrast with Lake Wells’s organisms.

Nets, glass slides, and Lugol's solution were used for collection and identification of plankton.

Microscopes and identification guides were set out for student use.

These were many of the previous collected organisms that were available for viewing by the students.