Self-Sustaining

A self-sustaining ecosystem is the ability to maintain a healthy condition without outside impact. In other words, the ecosystem is independent. For the most part, my aquarium is self-sustaining. My partner and I have not made many changes to our fish tank. The nitrate level has maintained around a 5ppm. The ammonia level has stayed at about a 0.25ppm. Our plants, fish, and even the bacteria have helped keep the aquarium to a healthy, independent level. They have kept healthy and alive to do their job in the tank. By doing this, the water is constant. The temperature has even remained the same. The water has been terrific usually and no changes have really been made. The only thing we did was add water and bacteria supplement. Keep in mind that we have taken care of this aquarium for 7 weeks now and it’s still thriving. Since our aquarium is doing so well, I would have to say it is self-sustaining. 

Nitrogen Cycle

The nitrogen cycle is a combination of many things. The first step is the wastes produced by fish. It produces ammonia and carbon dioxide in the water. The plants then take in that carbon dioxide and release it to the atmosphere. Nitrosomonas bacteria change ammonia into nitrite. Next, nitrobacter bacteria change nitrite into nitrate. Finally, plants and water changes remove the nitrate. The plants, animals, and bacteria play a major role in this cycle. The animals produce the wastes that are the cause of this cycle, plus they produce carbon dioxide and take it oxygen. Plants take in the wastes of ammonia and carbon dioxide, while producing oxygen for the fish to live. The bacteria are how the ammonia is changed and removed from the water. If one of these three things were not present, the ecosystem would not function properly. Without one, the carbon dioxide could be too high. The ammonia could not be removed or nitrite would kill the aquatic life. It is a balance and every part of the cycle is a key factor in making the environment healthy and working.  

A Lake and River

I would think that my aquarium is similar in water quality to a lake. They are both standing water so it has many similarities. In addition, a lake has aquatic life just like my aquarium. The only difference is that a lake has more fish and plants, so I would think it has a higher level of dissolved oxygen. My theory is also formed by the fact that a pond test results were almost identical to my aquarium water. However, the river I think would differ from my aquarium water. First of all, it is running water. Since it is fast water, the dissolved oxygen would be super high. There is some aquatic life, but not as much as a lake so the ammonia level would be different. Both of these waters would test the same in chlorine and pH because a certain level is required for life. Depending on whether the area surrounding the water is high in magnesium and calcium would calculate the hardness. Other than that, these are just a couple of reasons that I think my aquarium would compare this way to a lake and river.

My Aquarium

Meg and I have had successfully kept up our aquarium. It is doing well and surviving. The filter is working and blowing bubbles. The water is clean, no cloudiness. The plants we added a couple weeks ago are still alive, but with few leaves on them now. They seem to gravitate towards the window, since that is the source of our light. The fish are finally staying alive and interacting well with one another. We feed them every other day and they are still good. However, the water level of the tank dropped. I’m not sure why, but it was lower when we came to school one day. Besides that everything is great.

The last time we checked the water quality was September 30^th. The temperature remained constant at 82 degrees Fahrenheit. The ammonia level is a 0.25ppm, while the nitrate was a 5ppm. These levels are acceptable, meaning that our aquarium is a good environment for the fish to live. They aren’t going to die because of high ammonia or nitrate levels. The plants are helping keep this balance.

Dichotomous Key

A dichotomous key is used to identify organisms based off of characteristics. To use a dichotomous key, you start with the first question that has two choices to pick from. After you observe your organisms and answer the first question, then go to the right and look at the number it’ll tell you to go to. Keep answering the questions it leads you too, and eventually you’ll reach the answer. It will give you the name of your organism if you follow the questions exactly on what the organism looks like.

            Creating a dichotomous key can be difficult. We had to create one of algae in class. The first thing I did was branch them into two groups. After that, I thought of different aspects of that algae and how it differentiates from the others. Eventually I narrowed it down and finished bracketing them. Then, I wrote it out in questions for my dichotomous key and it worked. At first it was hard to differentiate them, but I used my notes and ended up succeeding. They all have a unique characteristic, but it’s hard to put it on paper to lead to one choice. However, with the help of my partner we finished it and solved all the problems faced. It was cool to make this key and see how it works.

Evaluating a Body of Water

How do you think we evaluate a body of water? Well the first step would be to observe the site. Then you would capture and identify algae and insects. Next, tests would be taken; such as pH, ammonia, nitrate, temperature, and dissolved oxygen levels. The very last step would be to run a panel of chemical tests, but this one is expensive so you would definitely do this last if you had too. These steps are in this order for a specific reason. If you can determine the water quality before running all types of tests, then those steps should be first. The algae and organisms help tell how the water is doing. Bad algae and organisms would be found if the pollution index is high. So based on what you find, helps determine this. The organisms can affect the water because of what they give off. They can either produce a lot of carbon dioxide or ammonia, which is bad for the water. However, the plants help get rid of this problem, so that is good. As you can see, it is very important that you observe the site first before taking the extreme measures.

Dissolved Oxygen Part 2

Dissolved oxygen is needed to survive. Two ways that dissolved oxygen can come from is contact with the atmosphere and plants in water. Carbon dioxide and oxygen works in a cycle in the aquatic ecosystem. Plants produce the oxygen, then animals use it. After the animals use oxygen, they produce carbon dioxide. The plants then take in the carbon dioxide animals’ produce. So both plants and animals work off of each other. It is a constant cycle of producing and using by interchanging who uses what. However, at night the dissolved oxygen levels decrease. This is due to the sunlight not being present. No sunlight means no photosynthesis being produced. This is why dissolved oxygen levels are decreased at nighttime.