Bio-Systems (Daniel Hill)

Title: Bio-Systems Aquarium Demonstration of an interdependent system.

Principle(s) Investigated: Systems occur naturally throughout nature, where various species become interdependent and support a habitat. Bacteria is not our enemy, it supports life in many positive ways.

Standards : Past in the appropriate California content standards.

Materials: A journal. A fish bowl (can be found cheaply at Petco, Kmart, Walmart or most pet stores). Gravel, for the bottom of the tank, aquatic plants and a few guppies and shrimp.

Procedure: I start with an overhead projection of a microscopic animal or plant that is weird enough to get the students attention such as a Clam Shrimp, String Algae, aquatic snail. There are many to select from that will draw the students interest or “need to know.” I identify the subject on the overhead and explain how it fits into a system, a complicated biological web of diversity that supports and sustains itself interdependently with the other species living within it the system.

Systems can be found all over the planet, in vast biomasses (such as plankton in the ocean) and in tiny microcosms we find them. On the overhead at this point I’ll show an interesting recently publicized story (video clip) about a Biologist who swam to the depths of an underwater seismic trench located in Iceland and found an amazing diversity of life. Even where conditions do not seem favorable it is amazing how life finds a way to not only survive, but flourish (show picture of underwater vents). Systems can be used to engineer fresh water pools without the use of chemicals, (show diagram of a natural swimming pool). These natural pools utilize a system of various plants and bacteria to purify the water. I will then show the aquarium and explain my class experiment in which each student will create and document their own system that (to start with) will include: 1. aquarium 2. Gravel 3. Guppies 4. Aquatic Plants 5. Shrimp. From this basic starter kit they will have the entire semester to encourage growth and bio-diversity by providing all the care and cultivation necessary for a prosperous tank. Students will also be encouraged to go to areas where there are ponds or streams in the wild and collect wild species of plants and/or animals and then see what effect those introduced species have on the tank over time. The students will keep an Systems Journal in which they document daily the developments in the tank. At the end of the semester the students are asked to write a three to four page paper where they compare and contrast their small system with another system that could be in the wild (a pond) or created by man (like the natural swimming pool or sewage treatment center). It must be a system with interdependent biological process occurring. In the paper they will be ask to explain the processes, flora and fauna that are in the system and how these relate to their aquariums system.

Student prior knowledge: Students would need to be prepared on the use of the microscope, collecting living samples properly, aquarium maintenance, and some basic computer skills are required. Students would also read chapters from a text book, such as Foundations of Earth Science that covers interdependent systems.

Explanation: Put gravel in the bottom of the fish bowl, plant aquatic plants in the gravel and arrange according to preference. Fill bowl with purified water. Put guppies and shrimp in the bowl. It takes around 1 month for the fishes waste to begin to settle into the gravel. Within the fishes waste is the bacteria that breaks down the wastes and turns it into nitrates and nitrites which can then be used by the aquatic plants. The fish use oxygen and produce carbon dioxide while the plants do the opposite. There are Clam Shrimp and larger fresh water shrimp which scavenge debris and waste and help break down the build up of the aspect of the system which is decaying. Soon the guppies will begin to mate as well as the shrimp. Guppies will eat their young but a few may survive that hide well. But this is where proper growth of aquatic plants helps the system and water grass is especially good for this purpose. The juvenile guppies and shrimp can hide in the water grass. Additionally, water grass is an extremely effective means of breaking down wastes, absorbing them and filtering the water, not to mention all the oxygen it produces for the guppies and shrimp to respiration. Within about a month another interesting thing happens and that is algae begins to grow on the sides of the tank and all over the plants and gravel. The fish will eat the algae and in my tanks they even prefer algae to the fish food I give them. I also have tiny snails that climb around the tank eating the algae. The tank needs to be placed in a location where it will get direct sunlight, but won't get so hot that it kills the guppies. So indoors near a window is good. Just an FYI cats are extremely attracted to these tanks and will drink the water (which doesn't hurt them) and eat the fish.

Questions & Answers:

1. How do systems play a roll in our everyday life?

2. Where can you see an example of a man made (or influenced) biological system that benefits our society?

3. Why are systems important to life on Earth?

Applications to Everyday Life: Our sewage treatment plants are systems that utilize bacteria to breakdown waste so that it can be reintroduce to the environment in a less toxic form. A bacteria has recently been engineered which can break down plastic so that we may in the future be able to introduce it to garbage dump sites in an effort to speed the process of breaking down the massive amounts of waste that our society produces. Our bodies and food and the materials we make our homes from all come from naturally occurring systems.

Photographs: file://localhost/Users/danielhill/Desktop/AED_ecosystem.png

Website: http://www.biotop-natural-pool.com/index.html

Videos: http://voices.nationalgeographic.com/2015/04/16/divers-search-for-tiny-animals-in-icelands-fissures/