TyW33: Bill, Dave and other have provided very good info. BACKROUND....I also have a active leased gravel pit lake approx 19-20 acres now but should be completed by the end of this year and the pit license turned in with some 22 acres at the end. In my situation, farm land was dug starting in 1988 and gravel and sand removed forming a ground water level fairly shallow pond-lake. The depth is determined by the depth of clay.
Once the pit excavator hits clay below the water they stop and move on creating more sand and gravel being removed and water created. The depth is mostly 6' or less but I do have 4-6 acres 12-14' deep. When I bought the house and property (Spring 2002) the lake was very clear with only stunted yellow perch and rock bass with no predator fish. I bought and caught mature LMB and SMB and added to the lake with great results along with 600 plus mature bluegill that spring of 2002. The spawns have been great since for the bluegill and LMB. I'm in SW Ontario, Canada @ 42 degree's north latitude. I too don't want to fertile but I added approx 40-70 domestic ducks and geese to help. The results are the clarity levels have reduced to the 3-4' range from 8-12' and the YOY are growing very well. The birds are eating the vegetation in the water and keeping it below the 20% range. Therefore, I have seen my bluegill grow to large sizes 6-10" from my good gene pool but have far less 3-5" BG. I believe my young LMB are targeting this size range at this time. The bass are very heavy in relative weight and most are in the 10-16" range when I fish for them. Each year my LMB are growing and becoming more dense in #'s and size. The yellow perch are reducing in #'s but they are growing from the 3-5" size to the 8-12" sizes perfect for the table. In talking with both Bill and Dave in the past.....remember there is only so much biomass in the lake and choose it wisely! In my case, the forage fish are culling all rock bass, yellow perch, bluegill and pumpkinseed with the LMB and a few SMB as predators. Maybe next year I will add a third predator "WALLEYE" to the mix but the lake is still under evaluation and my goals of both large yellow perch & bluegill with avg size LMB and SMB as predators with a few lungers throne in if possible. I hope this helps and isn't pond management fun......... remember what Dave says, this isn't an exact science and each situation may be different......trial and errors along the way as you move forward. Best of luck in the future and stay with your goals.
Rowly
