Your neighbor has fertilized her lawn. Several weeks later, she is alarmed to see that the surface of her ornamental pond, which sits at the bottom of the sloping lawn, is covered with a green layer of algae. (a) Suggest a feasible explanation for the algal bloom in the pond. (2 points) (b) Design an experiment that would enable you to validate your explanation. (7 points) Include and label in your answer: (i) a testable hypothesis. (2 points) (ii) the variable that you will be testing. (1 point) (iii) the data to be collected. (1 point) (iv) a description of the experimental procedure. (2 points) (v) a description of the results that would validate your hypothesis. (1 point) (c) Based on the data from your experiment and your explanation of the problem, think of, and suggest, one action that your neighbor could take to help the pond recover. (1 point)
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That's what I thought. You want someone to do your homework. Here's a hint: run off fertilizer causes an algal bloom.
You can read more about it here.
http://en.wikipedia.org/wiki/Algal_bloom
(a) One feasible explanation for the algal bloom in the pond could be the runoff of excess fertilizer from the neighbor's lawn into the pond. Fertilizers typically contain high levels of nitrogen and phosphorus, which are essential nutrients for the growth of algae. When these nutrients enter the pond, they can cause an overgrowth of algae, leading to the green layer on the surface.
(b) To validate this explanation, you could design an experiment as follows:
(i) Hypothesis: The excess nutrients from the fertilized lawn are causing the algal bloom in the pond.
(ii) Variable to be tested: The presence or absence of excess nutrients in the pond water.
(iii) Data to be collected: Measurements of nutrient levels (such as nitrogen and phosphorus concentrations) in the pond water before and after the neighbor fertilizes her lawn. Additionally, observations of the algal growth in the pond, including the intensity and coverage of the green layer.
(iv) Experimental procedure:
1. Collect water samples from the pond before the neighbor fertilizes her lawn.
2. Analyze the water samples for nutrient concentrations.
3. Document the baseline algal growth (if any) in the pond.
4. Ask the neighbor to fertilize her lawn as she normally would.
5. Wait for an appropriate duration, such as several weeks, to allow time for the runoff to reach the pond.
6. Collect water samples from the pond after the neighbor has fertilized her lawn.
7. Analyze the post-fertilization water samples for nutrient concentrations.
8. Monitor and document any changes in the algal growth in the pond.
(v) Results validating the hypothesis: If the data shows an increase in nutrient concentrations in the pond water after the neighbor fertilizes her lawn, and if the algal growth in the pond corresponds to this increase, it would support the hypothesis that the excess nutrients from the fertilized lawn are causing the algal bloom in the pond.
(c) Based on the data from the experiment and the explanation of the problem, one action that your neighbor could take to help the pond recover is to minimize or eliminate the use of fertilizers near the pond. This would reduce the amount of nutrient runoff into the pond, which should help limit the growth of algae and allow the pond to recover. Additionally, maintaining a buffer zone of vegetation between the lawn and the pond can help filter out excess nutrients before they enter the water.