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.

Lab 8 - Aquatic Ecology: Abiotic Components

Aquatic Ecology is a lab that is split into two weeks, the first covering abiotic factors, and the second covering biotic factors. The abiotic factors consist of heading outside to Lake Wells on the campus of Georgia Southern University. There the class took measurements of the quality of water to determine the lake’s health. Measurements covered water temperature, dissolved oxygen, pH, conductivity, nitrate and phosphate. The class was divided into groups and measured each factor. From there, the class went back to the classroom to finish up questions and come to a consensus on the water quality of Lake Wells.

This week consisted of my last week actually teaching the classes. I chose to teach abiotic factors because I wanted to gain both an indoor and outdoor teaching experience. The class started off with a quiz, but then I took over from there. I explained my lecture on abiotic components, covering reasons such as why we measure the quality of water, as well as what affects the quality. As my lecture concluded, I explained the instruments the class would be using. I then demonstrated the use of the meters, explained how the nitrate and phosphate test kits worked, and covered safety with said chemicals. I wanted to be sure that everyone knew the correct procedures before we went outside, where talking to the entire class would become a bit more complicated.

I led the class outside to our testing site, and then let them work amongst their groups to test the water. I made sure no one strayed, and went from group to group, giving advice and answering questions. Once everyone finished, we went back to the classroom, where I made a few final points about Lake Wells’s water quality before I let them leave.

Overall, teaching outside was an insightful experience. Keeping control of the class did not end up being too hard, as my classes have always been well behaved. I did enjoy making the final points at the end of class because I think that they really drove home the point of the lab and hopefully will stay in their minds. The only thing that could have helped this more would be the addition of another water sample test site to compare Lake Wells to. To me, I believe that I have improved significantly from my first time teaching three weeks ago. I feel more confident about my ability to address the class and deliver a well-spoken lecture, as well as to effectively lead students in lab work. Once I had gotten over my first time in front of people as a teacher, I have definitely felt more at ease in the classroom, and now I look forward to the next time I can teach.

Here I am demonstrating the proper use of the conductivity meter.