Is Consistant Tournament Pressure Hurting Lake Havasu's Fishery?
Currently Lake Havasu encourages tournaments every week end no matter what time of year it is or regardless of the spawn. Since the temperature of the lake determines when the fish spawn, will this constant pressure on the spawning fish during tournaments eventually effect the fishery. Already the Largemouth are being taken over by smallmouth which seem to do better there. The striper fishing is phenomenal, but stressed by the snow birds in the northern U.S. There are no perfect solutions for any fisheries until a proper understanding is developed about that specific body of water.
Now this is all theory based on personal, anecdotal evidence, but shared by most other biologists that I know. Generally in the south (where I spent my days in the field), where fishing during the spawn has been popular for the last century, population fluctuations can almost always be correlated with environmental factors (too much water, too little water, extreme temp variations, low nutrients, high nutrients, etc.). There has been some research that demonstrates if you remove the male (female actually doesn't guard the nest...just does her thing and moves on) for a few minutes, egg predation from other fish/aquatic organisms will clean out the nest rather quickly. However, that's not looking at the population level, which no one has been able to document an impact there.Largemouth will likely be dominated by smallmouth in an aging reservoir regardless of fishing pressure. It's simply a shift in the habitat complexity, which favors smallmouth (and generally spotted bass as well). As the amount of woody debris/aquatic vegetation is reduced and becomes more rock/boulder/coble, largemouth are at a competitive disadvantage, and the populations shift naturally. I've seen that in my own data numerous times. It can also go the other way if aquatic vegetation becomes established in relative abundance.