Ecosystem in a Jar – constructing a self-sustaining ecosystem

Create a self sustaining ecosystem and you hypothesise that a) the pH will stay within the range 7 and 8 and b) dissolved oxygen above 8 mg/L (is there a reason you have chosen these values? perhaps in your intro you should state what a healthy pH and dissolved oxygen range is for freshwater ecosystems, giving reference(s)). the overall hypothesis is that if you add the appropriate components you will be able to construct a stable, self-sustaining ecosystem in a jar.

Method: one cup of the fine sediment was placed in the jar, then 2 rocks were placed at the bottom, 1.5 litre of pond water (16.5 cm water level) was placed in the jar, then 1 strand of myriophyllum was placed in the jar, the shrimp and aquatic snail were also placed in the jar, and finally 2 spoons of azola were placed in the jar. the observations were made and measurements were made using a multiparameter. measurements include pH, salinity/conductivity, dissolved oxygen, phosphates, nitrates and temperature. the jar was then covered with a net and stored in a greenhouse. each week for the 5 week period the jar was removed from the greenhouse and taken to the laboratory i n order for us to complete the observations and measurements before the jars were once again returned.