question about a shallow weedy pond

so i have this pond thats part of a river system. its one of the best herring runs in the state. its shallow about 8 feet. lot of submerged weeds in the summer. some structure but not much. water is very clear. PICKEREL ARE EVERYWHERE!!!!!!!!!   but theres some of the biggest bass ive ever seen in this ponds! ive hooked em but havent landed them. the bite is very tough! and ill usually catch a dink bass or 2 and 100 pickerel.   ill fish anything from 4 inch plastics to 9 inch swimbaits. ive started using swimbaits in here more then plastics due to the amount of pickerel.  in the spring time when the herring run is when i do the best but rest of the year the bite SUCKS!!  summer fall winter! forget about it! 
my buddy caught a 6.2 and lost a fish much bigger last month! my other buddy did catch a 6.5 ice fishing here once!   
i did night fish it once! bunch of dinks, a 3lbser and a 4.9. 

any tips to catch them biggons here?  also my buddy says that the bass will follow the herring up and spawn in this pond then migrate back down to the amazing pond located down river. could this be true?