Marine Pollution

Part 4: Summary

In this part of the project, we propose a context in which you can summarize and report on your observations of the mussel pollution data. In general, all such reports should include answers to the following general questions:

• What were the goals of the project?
• What actions did you take during the project?
• What results did you observe from these actions?
• What conclusions did you draw from your observations?
• How do you justify your conclusions?

Specific context for this summary report: As the science reporter for the statewide newspaper The Maine Times, you have been assigned to write a short article concerning the Bowdoin College study of the effects of TBT pollution on mussel shell thickness along the Maine coast.

You may assume your readers are mathematically literate -- hence you can include formulas (e.g., the equation for a straight line) or data plots. However, you cannot assume that your readers have worked through any part of this module -- your report should be self-contained, i.e., it must be understandable as a stand-alone article, independent of the rest of the worksheet.

You should decide on a point of view for the article, e.g.,

• I must warn my readers of the danger of TBT pollution as revealed by the study, or
• I believe the study shows that the dangers of TBT pollution are not severe, or
• The study does not present enough data to form a definitive conclusion concerning TBT pollution.

Other points of view are also possible.

Here are some specific questions that you could address in your article:

• Do the data presented here convince you that a relationship exists between TBT concentrations in mussel tissue and the thickness index of their shells?
• Do the data presented here seem to support or refute the hypothesis that a linear relationship exists between the two variables?
• Could the variation of shell thickness be a result of factors other than TBT pollution?
• Should concern about TBT pollution be heightened or lessened by the results reported here? In particular, why should we be concerned about a few thick-skinned mussels?

This list of questions is designed to be suggestive, not definitive. You might choose not to address every question listed, and you might choose to address questions that are not included on our list. In fact, we very much hope this happens! "Real world" uses of mathematics involve more than "answering questions" -- they involve determining the questions to be asked! Determining the questions and interpreting the answers are often far more important than the computational procedures and details. On the other hand, interpretations should be supported, to the extent possible, by solid evidence.

Important Qualification: The purpose of this summary is to have you think about the issues involved in examining data -- we have not yet provided the tools to give precise answers to the questions posed. In particular, rigorous analysis of data requires statistical techniques that you may not know yet.