Give me the names of some lakes, and what end of the BWCA you're entering from (Grand Marais or Ely) I may be able to help you off the top of my head tonight, or later tomorrow, if I need to consult someone:)
As a former outfitter/guide in the bwca, I believe that I have looked at almost everyone of the DNR's fish studies and data on the lakes in the BWCA. I have noticed that a majority of the surveys were done in the 1960's. I have been given a couple of reasons for this by fisheries employees. The main reason is that the traps that are utilized are large and dangerous to use in a canoe. The dates pretty while well correspond with ban on motors and flights into the BWCA. A second reason given is that it is much more costly in man hours to complete the surveys, as fisheries biologist may have to paddle multiple days to a specific lake hauling the equipment necessary to do the survey. In addition the surveys take several days to complete to get accurate data.
If you look at the data, though you will find a lake classification. One of the things that I did was look for lakes outside of the BWCA that had the same classification. This would allow me to look at the trends that were occurring on similar lakes that have been surveyed much more recently.
I do believe that there is a long term solution to this issue and it has to do with creating a BWCA stamp for fishing within the BWCA. If a stamp closed $7-$10 dollars and was required of all anglers fishing within the BWCA, it would not be unreasonable to expect in the neighborhood of $500,000 to be available for the more costly surveys to be done on interior lakes and thus have better management of those fisheries. As an angler who fishes almost exclusively within the wilderness I sure would not mind paying an extra $10/year to have better fishing.
Actually, DNR fisheries folks access BWCA lakes by float plane to do their surveys. Some of the more popular lakes are surveyed every few years, but many more haven't been surveyed in decades.
On the more remote lakes, where angling pressure is of little consequence, it is amazing to see how similar the survey results are over time. The physical and biological factors influencing the fishery are usually pretty stable.
I would also like to see a BWCA fishing stamp, as well as reduced bag limits and the focus on trophy fisheries on some waters.