Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Managing black crappie

Are the LMB keeping down the crappie population by eating the large ones, or are the tiny BG keeping down the crappie population by eating thousands of fry?

Even if only a few crappie reach the correct size to spawn, a female BCP can still produce 40,000 eggs.

Although BG are for sure eating most of the swim up we have to also consider the sheer dominance of the BG population. They presently occupy the vast majority of the standing weight of LMB, BG, and Crappie. This means the egg bank of the crappie is substantially less than the BG. Also abundant BG probably cause some crappie nest failure. The net result? Perpetuation of the current status quo.

If Pat has a relatively small number of trophy size bass, what is eating the 2-3" BG in the pond?

In a pond that has low numbers of LMB that are very large ... there are not many BG produced in this size. Although they are fewer, the survival is good because the big LMB are focusing on the 3"-6" sizes that are more energetically favorable. Keep in mind that LMB eat proportionately sized prey. So big LMB eat similar numbers of BG that smaller LMB eat (provided they are growing at the same percentage rate of growth). The number of BG needed for prey is reduced when the population of LMB is lower in number. The 3"-6" prey that are more numerous when the LMB are fewer are the predators reducing the number of 2"-3" BG recruited. There have been a number of studies on the effects of intermediate sized BG on BG recruitment failure. They can be numerous enough that no YOY survive predation by them and overwinter. But also keep in mind that the intermediate BG that cause recruitment failure are also the size of prey that big LMB need. This is why, ponds that are top heavy in LMB may need supplementation of forage. Good news on that front is that it doesn't take a lot of supplemented BG to make a big difference. BG need to be > 30 mm in length to have good survival in the face of BG predation. BG supplemented greater than this size will tend to be eaten by LMB. If the numbers of small LMB are very limited, then most of those supplemented (even at that meager size) will survive to grow to the lengths needed by the big LMB.



Pat, have you checked for stunting of your BG? I agree with jpsdad above where he suggests adding a few smaller bass each year. I believe that would extend the balance of your awesome pond a little while longer.