Big Dave,

sounds like you have a bass heavy population. there is a ton of info on this site for correcting this problem. First I recommend you do some reading, plenty of info here. If the bass have been crowded for long periods of time you probably wont see many forage fish. I see lots of bass crowded ponds these days, if this is your situation I would remove 20 pounds of bass per acre. if you get take the length and weight of all the fish you catch you will notice a trend in the data, meaning the most of the fish will be a certain size and weight. Remove the bass that are the same size, dont remove the 4 pounders. the larger fish are eating other bass to make a living. you may have to remove bass for several years before you notice good results. if you dont start seeing some more forage fish in a year consider stocking additional (large) bluegill.

you mentioned fertilizer, I would not recommend you start fertilizing the pond until you correct the current situation. fertilizer will only compound your problems at this point.