Stu's OK, even our opinionated QJ political posters are OK too. 
Nothing wrong about having an opinion, even a strong one you try and encourage others to share. We still own our own. 

I am new here, and I see this discussion thread kind of fizzled out a couple years ago.  But as an angler and a professional fishery manager, I would like to offer a perspective on eating fish. 

I have worked as a state agency fishery biologist and fishery management supervisor for the Missouri Department of Conservation (1979-2002) and now the Wisconsin Department of Natural Resources (2002-present).  There is no doubt that angler harvest can significantly structure fish populations, and that harvest regulations can be our most effective tool for managing fish populations (single species) and communities (multiple interacting species).  In NW Wisconsin we have the luxury of being able to sample the fish populations in our lakes with much greater frequency and much better gear (because of motorboat access) than fish managers in the relatively inaccessible, non-motorized lakes of the boundary waters region.  So we are able to obtain enough information to customize harvest regulations in order to meet specific objectives consistent with lake-specific potential.  But in canoe country, it's pretty much "one size fits all" for harvest regulations, because agencies just can't afford to know or do any more than that.  That leaves the "eat or release" decisions largely up to anglers.  The base regulations are very liberal, and could easily result in overharvest of certain species in pressured waters.  But that does not mean there is not a harvestable surplus of fish for human consumption.  And some types/sizes of fish are safer to eat (from a contaminant standpoint) than others.

I would like to revive the long-standing ethic first recommended by In-Fisherman magazine decades ago -- SELECTIVE harvest.  It starts with the notion that eating fish is OK.  It's not amoral or selfish if done in moderation.  It simply takes advantage of a healthy source of home-grown protein that is consistent with an environmentally aware, sustainable lifestyle.  Selective harvest also means that we should try to learn enough about each lake we fish to know whether we have a harvestable surplus (a particular species or size range of that species); or if any level of harvest could trigger a population crash, undesirable shifts in fish community composition, lower catch rates, or poorer size structure of the catch than we would prefer.

Message boards like this can serve a valuable function by allowing anglers to share information about the relative abundance and size of fish available in remote waters that biologists like me cannot reach with effective survey gear.  Then the conscientious anglers among us (a majority, I truly believe) can decide what to release and what to keep for a meal.

I came to this site because I will be taking my first trip to the BWCA with my son during the first week of June, 2014.  We plan to explore and fish the Knife Lake Route from Seagull to Saganaga during a 7-day period.  We are counting on eating fish for supper, though we will have other food for breakfast and lunch.  I have spent quite a bit of time reviewing old MDNR survey records for lakes gill-netted anywhere from 10 to 40 years ago.  Gill-netting can tell us quite a bit about lake trout, walleye, and northern pike, but it is generally ineffective as a tool for assessing the population of smallmouth bass.  Bottom line:  I still don't know a lot about the lakes we plan to fish along the Knife Lake Route, but here is my early read, in general:

It seems that several, though not all, of these lakes will have walleye.  They should still be relatively shallow in early June this year (late spring expected), so we should be able to catch some.  We would certainly eat a small (<18") walleye or two in the evening if caught late in the day, but early in the day we would probably catch and release all walleyes.  At that time of year, we suspect it will always be possible to pick up a northern pike in the 24-26" range -- the perfect size to fillet and remove Y-bones from, so there is no real pressure to keep any fish early in the day in order to ensure an evening meal.  Anything bigger goes back in the drink to thrill the next angler.  And if the water isn't too cold this spring, we think it will also be possible to catch a smallmouth bass or two for supper in most of these lakes.   Because the big ones are such exceptional game fish (pound-for-pound the best fighting freshwater fish, in my opinion), we probably would not eat one longer than 14 inches unless we were desperately hungry.  We would also release walleyes >18" and pike >26" in order to reduce total intake of methyl mercury, which makes its way into fish even in remote wilderness areas (airborne product of coal-fired power plants hundreds of miles away).  Many research studies show that methyl mercury concentration is directly proportional to fish age (even more than length).  You don't have to be pregnant to be legitimately concerned about this.  But you don't have to abstain from eating fish either, if you choose your species and sizes wisely. 

Smallmouth bass are probably the safest to consume of all game fish in the BWCA, because they usually eat mostly crayfish when available, whereas walleye and northern pike usually eat substantial numbers of fish.  Eating "lower on the food chain," it takes smallmouth bass longer to build up mercury in its tissues than it does the predominately fish-eating predators like walleye and pike.  Small fish accumulate mercury (from eating plankton) and "biomagnify" it in the larger predator fish. 

Which species is most likely to be available in harvestable surplus?  Walleyes and pike CAN be, but not knowing the waters we will be fishing, it is more likely that there will be more smallmouth bass than are necessary to sustain a quality fishing experience.  It is possible that some culling of fish in the 10-14" range may even be desirable in some lakes, resulting in a higher proportion of 15-20" fish to catch and release for fun in the years ahead.  I will let our catch rates and sizes of fish caught be our guide as to whether keeping some smallmouth bass will help the population or hurt it. 

One more note on smallmouth bass.  I see a lot of folks referring to them as "invasive" species here.  I realize they may not have existed in many of these lakes a few decades ago, but smallmouth bass have always been an integral member of fish communities in northern glacial lakes what support walleye.  Despite what you may have heard, these two species are quite compatible -- rarely eating each other or competing significantly for the same food.  If you are a lake trout enthusiast, you may have a better case against the "invasion" of smallmouth bass, because the bass have been shown to consume many critters in the shallows that lake trout USED to eat, forcing the trout into a more deep-water, open-water existence than before.  But the thermal conditions created by climate change are likely to be a bigger threat to lake trout than the appearance of smallmouth bass, so let's appreciate these superior fighters at the same time we are enjoying whatever harvestable surplus of smaller ones Mother Nature may provide. 

OK... that's more than I intended to say, but hopefully it will offer a perspective not yet shared that some may find helpful.  If anyone reading this can offer some advice on what my son and I can expect to encounter on our early June trip around the Knife Lake route (so we can make conscientious decisions about what to keep and what to release), I will be most appreciative.

Dave