This essay was completely boring to me. It was, sadly, a lame topic that was about fish, honestly in a college English book I am sure that there is something more exciting to write about than the population of fish in a given area. I found this essay to be a "fill in" space for the book. Also because there are so many pictures it is obvious that they were trying to waste space in the book. As to the explaining a concept this story does a decent job at doing so. For some reason they seemed keen on giving out a whole bunch of information on fish and that was ok, because it was the topic, but then they started giving useless information about it which had absolutly no reason for doing so.