Question on lake biology

[BiglerM]

We have a 250 acre private lake in the neighborhood I live in which is just loaded with crappie. You can catch them any time of the year on that lake with ease and most are right at 10 inches. I think they are a little overpopulated. The lake is also stocked with bass, walleye, flatheads, blue cats, channels, and bluegill.

Would stocking shad in this lake be feasible? They put 250 lbs of fathead minnows in twice a year but besides bluegill and small crappie there isn't much else in the way of forage. Fish do feed on bugs quite a bit as there was a may fly hatch last night and the crappie were smacking them pretty good.

The lake has 2 feeder creeks that come into it and several coves for the shad to spawn in. What would your initial thought be? Lake is also 30 ft deep and is mostly sand/mud bottom.

Thanks

[Craig Johnson]

We have a 250 acre private lake in the neighborhood I live in which is just loaded with crappie. You can catch them any time of the year on that lake with ease and most are right at 10 inches. I think they are a little overpopulated. The lake is also stocked with bass, walleye, flatheads, blue cats, channels, and bluegill.

Would stocking shad in this lake be feasible? They put 250 lbs of fathead minnows in twice a year but besides bluegill and small crappie there isn't much else in the way of forage. Fish do feed on bugs quite a bit as there was a may fly hatch last night and the crappie were smacking them pretty good.

The lake has 2 feeder creeks that come into it and several coves for the shad to spawn in. What would your initial thought be? Lake is also 30 ft deep and is mostly sand/mud bottom.

Thanks

A very important question would be "what is the goal for the lake"? Are most anglers wanting to catch crappie or bass or cats or walleye?

It sounds like your current predator populations may be doing a good job of controlling the panfish numbers if most of your crappie are in the 10-inch range. Crowded crappie will usually measure much less than that, around 5 to 6 inches. If the crappie are very abundant and are 10 inches long and you want bigger fish then harvest a lot of the crappie. By thinning the herd there will be more resources available for the remaining fish and growth rates may improve. Keep in mind that trying the "thin the herd" via angling in a 250 acre private lake would likely require A LOT of harvest!!

Adding shad may sound good as seasonally they can provide abundant forage for sportfish. The problem is that adult shad get BIG and unusable to all but the largest sportfish. Shad can also produce very high populations densities and these densities left unchecked by adequate predation can cause problems for the sportfish populations. Shad eat plankton, same as young sportfish. Too high of densities of shad decreases available resources for bluegill and young bass and 'gills and bass will suffer.

It sounds like the panfish are the forage source in your lake. Adding shad may decrease the predation on crappie as bass, walleye, and bigger cats switch from eating crappie to eating shad leaving more crappie in the lake. Higher densities usually equates to smaller individuals and slower growth (stunting).

If you are relatively happy with your current crappie population, I would recommend harvesting more to reduce density and see if that improves your size distribution. Changing harvest strategies is much easier than trying to remove shad from a lake!! A 10-inch crappie in a Kansas lake is a pretty nice crappie, especially if you have easily catchable numbers!

[skinner80]

Just curious Craig have you ever seen a lake turn around to have quality sized Crappie or Largemouth from increased harvest after It has gotten overpopulated with stunted 6 to 9 inch fish that you were referring to. I have in a real small farm pond but never have in something 50 acres or bigger.

[Craig Johnson]

Just curious Craig have you ever seen a lake turn around to have quality sized Crappie or Largemouth from increased harvest after It has gotten overpopulated with stunted 6 to 9 inch fish that you were referring to. I have in a real small farm pond but never have in something 50 acres or bigger.

skinner80,

Yes, I have seen lakes show improvement in fish populations. Reasons for improvements are usually multiple vs. only increased harvest. Harvest is immediate and helps decrease density RIGHT NOW. Predation is also effective in controlling crappie density but it takes longer especially if you have to establish or modify an existing population to provide the needed increased predation.

More than one single management option is needed to improve fisheries in poor shape. The lake manager(s) need to have a goal and a plan as improving undesirable fisheries can take several years.