Hypothesis:
This experiment will evaluate duckweed and its ability to remove nutrients and toxins from water sources. Thus, duckweed will kill the organisms that require similar nutrients, yet aid the organisms that would otherwise die to toxins. Specifically, if one was to place Elodea plants in a tank with duckweed, then the Elodea will die due to the lack of nutrients from the duckweed having used the nutrients for its own benefits. Furthermore, if one were to place an organism such as Daphnia in a tank with Duckweed, then the duckweed would remove any toxins present in the water and provide a food source to the organism, thus sustaining the life of that organism.
Materials:
Method: …show more content…
Elodea: We will begin by obtaining elodea by online purchase, obtaining water from Nahant Marsh, and collecting duckweed from Nahant Marsh as well.
We will need enough water from the marsh to fill all four tanks needed in the Elodea experiment as well as the beakers/tupperware containers in the Daphnia portion of the experiment. This is also true for the duckweed needed from Nahant Marsh: we will need to collect enough for both tests to our hypothesis which will be enough to treat two tanks with Elodea and half of the containers for Daphnia. Once all of these materials are collected we will create our tanks to observe the Elodea. All of the tanks will have 10 Elodea plants (for the sake of replication) in 1 inch of tank rocks and filled with the water from Nahant Marsh. The independent variable in this test will be whether or not the water in each tank will be treated by duckweed and whether or not the tank will have extra nutrients (1 inch of topsoil) added. The setup of the tanks is shown in Table 1 below. Each tank will be observed for 4 weeks. Then to replicate and observe more data we will go through the process again after cleaning the tanks and disposing of the materials from the previous data
subset.
Table 1:
Tank 1 (control) Tank 2 Tank 3 Tank 4
No nutrient addition No nutrient addition Nutrient supplement added Nutrient supplement added
No duckweed treatment Treated by duckweed for 1 week No duckweed treatment Treated by duckweed for 1 week
Daphnia: First we will order the Daphnia from an online source, will be using water and duckweed from Nahant Marsh, and keeping the Daphnia in multiple containers. The Daphnia will be living in four separate containers, that contain the four different waters similar to that of the Elodea experiment, those being water that isn’t treated, water that has only duckweed and, water that has a pollutant, and finally water that has duckweed growing and is treated with our pollutant. To ensure the basic of survival of the daphnia we will be feeding them wheat flour. Per each container there will be a total of 10 daphnia and we will measuring the reproduction of the daphnia along with their survivability in each of the select environments by counting both the amount of daphnia that are floating or sinking (dead) and counting the daphnia that are active (live). The daphnia will be observed for 4 weeks since their average lifespan is 56 days and if the daphnia survive up until the end of observation that it is right to assume that they will live until the end of their life cycle. We will be testing the hypothesis multiple times by cleaning all materials so no cross contamination occurs between the present experiment and the past.