Pond Boss Forums INTRO Questions & Observations grass carp

Doc -- My guess is that most fisheries folks are going to agree with you.

Certainly, every time you come around a corner and startle a grass carp, they stir up the entire area! Similarly, they are difficult to remove if/when you decide there are too many. I hate to call them "smart," but everything I've ever tried works about one time, and never again.

Biologically, the biggest problem with grass carp is what I call the "all or none syndrome." Very commonly, we stock grass carp, see little reduction in submergent vegetation for a year or two, and then the next spring, nothing comes up. The reason for this is pretty simple. It's not the number of grass carp/acre of vegetation that control the plants, it's the pounds/acre. As they grow, suddenly they will be in sufficient weight and essentially eliminate all the vegetation. It is VERY difficult to get any type of partial vegetation control with grass carp without knowing a lot about type and abundance of plants, number of grass carp, size of grass carp, etc.

It's probably not as severe for those of you in the southern part of the country, but in the Midwest (including us in SD), the submergent vegetation is the key habitat for maintaining good largemouth bass and bluegill reproduction and survival. We just can't get by without it.

I've noticed that most pondowners seem willing to tolerate a lot less vegetation than biologists think is good for a pond. Let's say that we think 20-30% coverage is ideal. Most pondowners would say that is too many "weeds." I usually try to get them to rake or perhaps chemically treat a localized area -- perhaps a swimming area or some fishing lanes. As you indicated, we can talk and talk about the value and importance of the plants, but not everyone listens!

I'll be very interested to hear viewpoints from other areas of the country.

Dave Willis