I have a small pond that the fish population has decreased significantly over the last five years. Let me give you the history of the pond first.

* Pond was built in 1982 in northwestern Ohio
* Pond is approximately 1/2 acre of surface water and is 13 feet deep at the deepest point.
* Pond is well constructed with stone and sand all around the edge to eliminate wash out.
* Pond has never had structure for the fish
* Pond is fed with downspout runoff from the house and well water that is discharged from two Geothermal heat pumps. Pond is constantly full of water even in the middle of summer.
* Pond was stocked 1983 with Large mouth bass, Blue Gills (not hybrid blue gills)and Channel cat.

Over the years this pond has had an excellent balance of fish. Bullgill over running a pond is very typical problem around here. But this pond has not had that problem. There have been weed problems on and off throughout the years. They were always managed with copper sulfate. After one particularly bad year with the weeds, I decide to add some grass carp. The local fish hatchery recommneded two grass carp for this size of pond. With the weeds as bad as they were, I decided that I would add twelve grass carp to accelerate the weed removal. The grass carp were about 8-9 inches long. In October I took twelve home and placed the bag in the beach area of the pond to let the water temperature balance out a little before I released them. I went into the house for a short time. When I returned I noticed some very large bass up close and looking at the bag of grass carp. Well you know what happened, as soon as I turned them loose it was a feeding frenzy. I called the fish hatchery guy up and I told what had happened. He said that he was going to drain a couple ponds, and he would bring larger grass carp over to me that the bass could not eat. What he brought were ten grass crap about twenty inches long and two that were close to thiry inches.

They were placed in the pond in 1998, and they certainly have taken care of the weeds. But, I feel that they have caused the fish population problem. I don't think that they eat fish. What they do is swim up around the banks and shallow areas and inadvertantly destroy spawning nests with their tails. They are so large that the blue gills and the bass cannot force them away from their nests. I didn't notice fewer fish until about five years ago. This makes some sense that I didn't notice a problem right away. If you thing about it, there would be fewer and fewer fish successfully spawning each year. Eventually the older ones die off, and there are fewer younger ones to take their place. This problem would only accelerate with the grass carp growing larger and more destuctive due to their size. This is just my theory, and I am not sure that they are the problem.

One final thing that you might be thinking about. The Channel cat are not the problem. Nearly all of them have died off from old age. They evidently did not spawn well in our pond and the original ones are all gone now.

If removing the grass carp is the first plan of action. What would be the best way of removing them? They spook easily and I have never gotten them to bite on anything on a hook. Once they are out of there. Do I restock or let the bluegills and the bass that are still in the pond bring back the population?

I would appreciate any suggestions or comments. I am new to this site, and if this type of problem has been discussed at lenght before I apologize.