Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations 20 Bluegill caught. PSD?

Ok so my mom and dad went fishing last night and they said they caught 20 BG.

6 of them 8 inches
1 / 8.5 inches
1 / 7 inch
12 / 6 to 6.5 inches

What does this tell me from a PSD standpoint? I have to many 6 inchers?? Maybe I should harvest some in that size? Or will my 6 inchers be nice 8's next year and my 8's be nice 10's. Should I wait 1 more year before I start to harvest?

Man this whole harvest management thing is just as hard if not harder than the whole stocking of fish!

RC

Well, RC, what you have here is a lesson for budding young fisheries biologists. For bluegill, PSD is the percentage of 3 inch and longer bluegills that also exceed 6 inches. So, your PSD is 100. What does that mean? Well, I would want my students to come to the realization that angling doesn't provide a random sample of all sizes of bluegill in the pond. The sample is biased "high," because your sampling gear probably isn't going to catch a 3-inch bluegill?

Now, not to make this more complicated, but we also look at more length evaluations than just PSD. In this case, of your 20 bluegills, 7 (35%) were 8 inches or longer. This is desirable from a fisheries management persepctive.

When were the fish stocked? That might help us guess whether you still need some time to reach the upper limit of growth potential.

Hey Dave thanks for your input on PSD and size ranges and all that can get kind of fuzzy in the head that's for sure and any help would be great. I stocked these fish in 2010, and started feeding them AM 400/600 in 2011. I now have caught a few CNBG that are hitting 9 inches and we even caught one a couple weeks ago that was 10.5. I do have some nice looking bass in the 17 inch range to help with keeping the 2 to 4 inch BG's in check also.

Thanks,

P.S. Whats amazing to me is the difference in size from a 6.5 inch BG to a 8 inch! Wow what a difference! The 8 inch is so much thicker and taller and just all around big compared to a 6.5 inch.

RC, let's wait and get input from folks with experience in your general geographic location. However, my first thought is that your bluegills are still young, and you need to see if those first stockings make it to at least 10 inches or a bit more. If not, then you might want to consider more intense management. Given your feeding program, I am guessing that you just need a few more years.

Yes, it is amazing how fish can really start to stack on weight as they grow. You probably recall that Lusk and I had a bluegill standard weight table in the March/April issue of Pond Boss magazine. Below, I repeated the weights at various inches for bluegill -- you can see how weight goes up so much faster than length, so a good example to share with everyone

6 in = 0.16 lb
7 in = 0.27 lb
8 in = 0.42 lb
9 in = 0.62 lb
10 in = 0.88 lb
11 in = 1.21 lb

Plus, remember that these are just the standard weights to achieve a relative weight of 100. Given that many plump bluegills on fish feed can have relative weight values of 130 or 140 on average, you can multiply the weight in pounds times 1.4 and see just how plump an 11 inch bluegill might be (1.4 X 1.21 lb = 1.7 lb)!

RC great thread.

Dave excellent info as usual. Heck I wasn't aware of some of that.

RC from a different perspective but with the same result as Dave.

Keep in mind you have HSB in there as well. Look at the range of BG sizes you just set out. What is common about them? All of those fish are first stockers or survivors. All are just a little to big for the 17 inch and smaller LMB to eat. I don't ever harvest my stocker fish. They are there to set the table (so to speak) for your ponds future. Its not those BG that need mgt. but rather their offspring. Same for LMB. One reason, in addition to Dave's sampling point , that you may not be seeing/catching 4-5 inch BG is that they are the perfect size for your 17 inch LMB and possibly some of the HSB (4 inch and smaller). With 100 PSD and RW at 100+ you are confirming that your stocking plan is dead on. The question is can you maintain balance with the offspring. The best way to keep balance is to avoid messing up the stocking program by taking out your original stockers and their first generation replacements. My opinion is leave them for another year and then check your population balance , condition , RW , PSD etc. on all species. If you take any out fish then harvest 10-12 inch LMB and 4-5 inch BG. Of those do not take out more than 3 BG for every LMB in those ranges. A general guideline - take out LMB that would eat the size of BG that seem to be missing or are low in #s.

Ok Dave / Eric

Thanks for that information!! That helps big time! Some of this can get confusing for sure but you guys help clear the fog and that is very appreciative. Your right Eric I haven't really factored in my HSB but they are pushing 2 pounds now and I am sure they can eat some of the smaller BG at this point. I will wait one more year and see what I got. If those 6 inchers can become 8 and the 8's become 10 man next year should be some awesome fishing!!!

On a side note. I havent caught a bass lately that was under 15 inches. I think they are growing like wild fire with all the forage they have now.

Thanks guys for your help!

I think you are on course and those nice fish (BG and LMB and HSB)you posted pics of are in good condition and are your stocker fish. They will grow well ! Its the offspring that have to be managed.