Excel/Stats help

Having trouble wrapping my head around what I'm sure is a fairly basic concept, hoping y'all can help. I have a large data set containing abundance counts for several species of trap-caught fish, each at a different location, (about 800 traps in total). The data is GPS-referenced and falls into 6 distinct areas when plotted on a map. I've been instructed to produce species abundance histograms for each area, "normalised by the number of traps".

With only MS Excel at my disposal, I'm assuming this operation is not too complicated, but would appreciate somebody pointing me in the right direction. Have tried Google'ing, but finding the info difficult to relate to my situation.

I would think "normalized by number of traps" means that you need to divide the fish count by the number of traps. I'm thinking what they really want is a histogram of the percentage of each species of fish in each district, right? So you only need to come up with that data set from your existing data set. You need these columns: Species, district, count. I think you're probably going to really need just species and count, and need 6 of those, one for each district.

Try this page:
http://www.wikihow.com/Create-a-Histogram-in-Excel

and work on 1 district at a time, with "bin" being "species" and "frequency" being the count of each species in all the traps in that district divided by the number of traps in that district. I think that should do it, but I'd have to play with it.

Thanks a lot Dr. Hess, that's a great help.

Yes, I agree with the good doctor. By normalized, they mean they want the number of traps filtered out so that it doesn't look like fish are twice as abundant in a particular region just because there are twice as many traps. Averaging, as Hess mentioned, is the easiest way to do it. You could report the data as a group of percentages (if the mix of species by region is the important point) or by average numbers of each fish per trap (if the relative abundance in differing regions is the important point).