Everyone has their preference of what size fish to catch, keep and eat. But can science help us make the best choice. You can catch walleye and crappie in many lakes and rivers throughout the U.S.A. and Canada. There are many different regulations as to what size and how many fish you are allowed to keep, and take home to enjoy at the dinner table. Science has thousands of comparative studies with conclusions based on theories. In fact there are so many studies, it would almost be impossible to go back and read them all just to catch up. Science is and will always be a series of trials and errors to clarify the answer to a theory. Sometimes a theory is resolved, and then new discoveries such as DNA can change the results of what we thought were complete. Nothing is absolute in the world we live in, because the world changes. So what is the best walleye and crappie to keep in the kawarthas. You can't compare the fish in Lake Erie to Balsam Lake for example. Lake Erie walleye and crappie grow faster and die younger, and the walleye and crappie grow slower and live longer in Balsam Lake, as well as the rest of the Kawarthas. For walleye, many anglers say, keep the 14 to 16 inch walleye. Others say, keep the 16 to 18 inch walleye etc. etc. There are anglers that release all the big fish for spawning, because of the amount and size of the eggs. In walleye hatcheries they use multiple sizes of walleye. Some use 18 to 22 inch walleye, and some use 20 to 24 inch walleye. There are some that only use very large walleye for their controlled spawn. Many hatcheries rotate their stock and use many different sizes of walleye. We should all be thankful that our past generations finally woke up, and are trying to increase and sustain the walleye population all over North America. When walleye and crappie spawn in the wild, the rates of survival are drastically reduced. The best way to ensure a healthy and sustainable population of any fish species is conservation. Just because you are allowed to keep a certain limit of fish, does not mean that you should. It is up to all anglers to preserve our fish. A regulation is just a piece of the puzzle, common sense should tell you when.....enough is enough. I do not mind saying that I keep some big fish. The forum members that read and comment on my posts may have noticed a change in my own fishing practices. Last year was my best fishing season overall in my life. Too many fish to count because of the time spent out there waiting for the next one to hit. No small fish were kept, unless injured. Some medium size fish were kept, and a few large fish were kept. A few thousand fish we released to grow and make more fish for the future. My own personal plan is to keep less fish from now on. The family is not too happy with me because they just love a fish BBQ. They will get over it. LOL. My love of fishing is about the unknown, and what will happen in the next instant as I wait for some monster to hit that lure in the dark. If I am lucky and do catch the beast, I will let it go. Not because of some regulation or some theory of science. Conservation is the best way to ensure a species continues to exist. I love Mother Nature and the adventure she provides. Of course I will keep some fish, but not as many as in the past. More steak for me from now on. Don't forget to leave all species of fish alone when they are spawning. Be a good angler. Mother nature is watching.