Hello OkTex and welcome to Pond Boss! A 98 acre lake? WOW. The answer to your question is, IMHO, yes you should be managing the lake. A BOW is constantly changing and in order to keep the fishing good and the water quality good you should at the very least be keeping records of the fish being caught. Record the species of fish, the length of the fish and the weight of the fish. Compare the weight of the fish to standard weight tables to assess the relative weight of your fish. This will help you assess the health of your fish population.
Post photos of your lake when you can and hang on for an expert opinion (as opposed to my dribble). Thanks for posting, we're glad you found us!