Today we are terminating the experiment with the eels. All eels from different treatments are weighed to see if growth differed in the different treatments and to test for accumulation of iron on the gills we place a filter paper between the gills, leave it there for 30 seconds to absorb iron and then place the filter in acid before the actual iron analysis. 

We expect there to be more iron on the gills of eels from brown and salty water. Unfortunately, it will take a few days before we have the results.