Unit 4 Reflections: What is Energy and Energy in an Ecosystem- A Vital Commodity

Unit 3 tests are finally graded.  I was THRILLED to see a narrowing of the "great A/F divide" in my standard class.  Grades were higher than usual on the whole, and the number of failures was cut in half.  Some progress is better than no progress!

Verbal and diagrammatic representation of the energy in the "What is Energy" Lab

Unit 4 started off with a lab:  What is Energy?  Like many of the other activities, I found it took an excessive amount of time for a concept that the students were already pretty solid on.  There were 10 stations for groups to observe.  If I do it again, I think I may reduce the number of stations in half.  I found my students were familiar enough with the concept that energy cannot be created or destroyed and that it can transfer forms.

The teacher notes recommend reading the book, "Zoom" by Istvan Banyai before jumping into the next activity.  We didn't for two reasons:  1) We are really, really, really running short on time, but more importantly 2) I ordered the book last week off Amazon and it still hasn't arrived.  Maybe next time around.  My segue was just telling the students that we would be observing energy at the ecosystem, organism, and cellular levels.

I think the Energy in an Ecosystem- A Vital Commodity was great, except for one pesky detail.  In every single class, one of the trophic levels performed "better" than it should have despite me adjusting the numbers of each organism.  In both my honors classes, for some reason the dolphins acquired more energy than the cod:

Dolphins have more energy than the cod and the shrimp!

This has been easy enough to address through discussion, but I am still worried it is reinforcing a big misconception that the top organisms have the most energy!  I was trying to wait to stop the simulation until some dolphins died, but the problem was that my shrimp and cod were dying faster than the dolphins despite sufficient numbers of plankton.  If I waited for the dolphins to die, we would have had very little data.

In my standard class, who hasn't white-boarded yet, the cod were higher than the shrimp, which may make a huge mess when we graph.  I told them we might repeat the simulation tomorrow.

So we don't have that perfect graph to tip on it's side to make a nice half of an energy pyramid, because our data is off.

In the future, I might plan to repeat this simulation a few times until we get usable data.