Blog Assignment #7: Biosphere Post

Our big snail died early on. Seen here are some smaller snails paying their respects.

Week 1 Photo
The snail is dead and being visited by its tiny mourners. The shrimp is also still alive but camera-shy.

Week 6 Photo
Around the 4th week, the green algae started to develop.

Ingredients of our small Eden.

The red algal wasteland of the corner biosphere.

Items added to other Biosphere

Questions

• Why did you choose to include the organisms that you put in your biosphere? What was your rational (i.e. more heterotrophs, equal heterotrophs to autotrophs, etc. and why)

In our group, we decided early on that we wanted to add all the heterotrophs possible because it would make the biosphere look more exciting with many organisms floating around. However, we wanted to focus on the survival of the snails in our biosphere. Horea brought up the fact that snails lay eggs on rocks, so we added a rock in the middle of the environment to make reproduction easier for the snails. For the autotrophs we added a lot of plants for the snails to munch on. We also added Anabaena because we thought they were cool in lab but didn’t want the biosphere too crowded with organisms so they would fight for resources.

• What is the function/role or each of your organisms in your biosphere? What did you see them do?

As we said, the snails were the focus of our biosphere. The plants existed to make the biosphere less barren and a little bit more friendly but in the end they served the purpose of the snail’s food source. The Anabaena are supposed to fix nitrogen but we just added them for fun and didn’t really expect them to do anything.

• What changes did you observe in your biosphere over the last 6 weeks?

Our biosphere initially had the clearest environment (water), but it progressively got dirtier. It isn’t as clear anymore and the surface of the rocks are covered in shrimp poop. The water looked more green than when we started as well.

• Were there any surprises?

After a week into our experiment, our giant snail died. We aren’t quite sure why the giant snail died while the smaller ones didn’t. Other than that, our organisms turned out okay.

• Would you expect your biosphere to continue to function/survive? Why?

We believe our biosphere will continue to function and survive because throughout our experiment the shrimp and small snails showed signs of growth. However, the big snail died, so we expect that our biosphere will still survive for a little bit, but since the big snail didn’t survive we consider our main objective failed.

• Compare your biosphere to another group's biosphere? What are the similarities? What are the differences?  How do you account for the differences?

The biggest difference in our biospheres are the color of the water. We mainly put the same organisms in the water. However, they had three more shrimp than we did. That’s what we think caused the water to turn that horrible red/orange color. Earlier on in the quarter, we noticed that the shrimp died and started to look cooked. We thought the sun was just hitting them in the right way, but since all of their water turned near the same color we believe that the shrimp definitely had something to do with it.

• Reflection: What did the biosphere teach you about how ecosystems function?

The biosphere taught us that slight climate change can be extremely disastrous and even wipe out an entire ecosystem (Seen on the red tank). We think that each seemingly small aspect plays a much bigger role in the health of the ecosystem when it all adds together.

• Write at least 3 scientific questions based on your observations of your biosphere.

What are possible factors that can cause our giant snail to die?

What caused the other group’s water to turn red?

Would the same biospheres in a dark room turn out the same way?

• Write 1 hypothesis based on the questions above.

The water turned red in the other group’s biosphere because when the shrimp died, their corpses leaked something that changed the conditions of the environment.

• Write an experiment your group could run to test the hypothesis above.

Fill another biosphere with the exact same ingredients and leave it in the same spot on the windowsill except leave out the shrimp and then see if the water turns red again.