Journal Looking Back

Week Four We put the two pieces of our model together.  We are not entirely satisfied with our model but we are ecstatic that it works as well as it does.  We know that realistic data would enhance its functioning and usefulness, but the process of creating it was immeasureably educational.  We are now able to add variability to the anthropogenic input of mercury, the pH levels, and the temperature.  We are able to graph the concentrations of methylmercury at each trophic level as a function of time.  We can vary parameters as the model is running and make observations of the effects of each variable separately and as they interact with one another.  We can ask questions and test it with our model.  We have become "experts" of sorts.  See Final Model. We present our final thoughts as a list of our learnings:   What did we learn about biomagnification?

• We learned the details of several disasterous mercury spills: in Minimata Japan, in Iran, and among the Cree Indian community.
• There are ongoing, extensive studies of methylmercury poisoning in the Seychelles, in the Everglades, and in the lakes of Wisconsin.
• Hair sampling seems to be the most accurate method of determining the extent of mercury poisoning.
• Mercury pollution is much more prevalent that we had imagined.
• Methylmercury is the most toxic form of mercury.
• Bacteria living in the sediments of rivers and wetlands are responsible for converting mercury into methylmercury.
• Some organisms have the capacity to accumulate more toxins than others, primarily due to the amount of fatty tissue present.

What questions remain?

• How do phytoplankton and zooplankton interact with methylmercury in the environment and what role do each play in the biomagnification process?
• To what extent is mercury pollution controllable?
• Is it possible to come up with biological or chemical solutions to the problem?
• How does land use changes affect the extent of mercury pollution?
• Does mercury have any toxic effect on plant life?

What did we learn about learning science?

• We learned that we don't normally think about the details in a system at the same time as we think about the system as a whole.
• We learned that almost every thematic unit that we teach back at our school can be taught from a systems perspective, and that good tools exist to allow this to happen.
• In the midst of uncertainty it is easy to fall back on the teaching of "factoids." It is easy to teach about the individual parts of a system or to tell students what we want them to know.  Our experience has confirmed that depth of understanding happens when doing science.
• Using a modeling system forced us to go deeper, to examine our assumptions, to make connections and make them more clearly, to evaluate our decisions, and  to ask questions.
• The requirement to produce a web page raised the ante significantly.  We tried to produce a product that we could be proud of.