Pond Boss Forums INTRO Questions & Observations The Grass Carp: Your Vote?

There's been a good bit of discussions about our friend, the grass carp. During discussions, it's hard to tell if forum members are pro GC or con GC. I suppose that some members are ambivalent regarding the scaley specimen.

Could I ask two questions?

First: Do you currently use/have grass carp?

Second: Are you for or against the grass carp? (for this, please answer as if you had to give a "yes" or "no" without qualification. Then if you want to qualify, please do.)

Technically, I don't have any Grass Carp, so I'm leaving myself out of the survey.

Sunil, I currently have grass carp in three of my ponds. They are extremely useful in keeping my levels of macrophytes under control. I think they're neat looking fish that taste delicious.

Several of the pond's that I have managed were at one time or another stocked with grass carp in high density levels without regard for the fact that they can be difficult to eradicate if they over consume. These particular landowners are extremely disappointed and blame the supplier who recommended these rates of stocking. I believe that this particular supplier may have been profit motivated beyond his motivation to evaluate the entire picture of the pond. A person like Bill Cody or Bob Lusk or Todd Overton would probably use multiple criteria and thorough analysis of the situation before simply saying "Pond X needs Y number per acre of grass carp". More simply put, I think there needs to be a thought process one uses to be certain of the necessity of using grass carp.

Sincerely,

Mr. Too Wordy

1st ?. I do not currently have GC but have used them in my two previous pond managements. I had two GC in a 1/3 ac pond that I drained this spring. I have recommended local people use GC in numerous weedy pond situations. Most people stock too many in trying to eradicate pond weeds. Pondweeds are beneficial, some weeds are more benefit that others, similar to fish and people. Many people make the mistake of stocking number of GC per surface acre as opposed to number of GC per VEGETATED acre of water.

2nd ?. I am pro grass carp in the correct or proper situation.

Thoughts - Experiences.

1. Too many GC per acre are bad and denude the pond and then contribute to extra turbidity.

2. The type or specie of weeds has a big affect on how much weed growth each fish will eat. Fewer fish will control tasty weeds whereas more fish are required to control non palatable weeds. Some weed are more palatable than others. GC by eating all the good tasting weeds, can actually contribute to establishment of a unpalatable and different type of weed in some ponds.

3. I am convinced that some grass carp have different tastes for weeds (individuality). Sometimes 3 GC will provide effective control whereas 3 different fish in a different & same sized pond will not control the same specie of weed. Go figure.

4. I currently do not have them because I am able to manually remove and adequately manage the vegetation. Most of my current underwater pond vegetation is planted / introduced and management is feasable. Certain types of water weeds spread slower, are less intrusive, easier to manually control, and are more fish & angler friendly.

5. For ponds 1 ac or less with a weed problem, I recommend the owner remove as much vegetation as posible / feasable. When it gets uncontrollable, the owner should try to remove 25% of weeds, stock enough GC to eat 25%-35% of the weeds and leave the remaining 40% to 50% of the weeds for fish habitat and competition against filamentous algae. Very Often when all the vegetation is removed, it is replaced in volume by filamentous algae. Nature demands that some type of plant utilize the available nutrients. More nutrients accumulate each year in a pond. The type of pond watershed and the management methods determine how many nutrients each pond obtains each year. Shallow ponds (less then 8ft deep)are problematic for weed growth.

Sunil :

No GC in my ponds as there are no weed problems that would cause a need. However this year the pondweed is to the point in one pond where if I can't control it within reason it may be time to add them.

Nither pro nor con. I view them as an tool to use as needed after a through review of the situation and a full understanding of the proper use. ewest

I believe I have one. It's a whopper. Stocked 7. They did a bang up job on a weedy mess. When the salad disappeared; all but one of them did.

I can't prove it but at one time I think (almost know) that their rooting around caused a mess that looked like grey water.

I would do it again if I get another big mess of weeds.

I put three in my 1/10th acre trout pond because I found literature from Canada that shows they can control vegetation in a trout pond if you up the quantity to compensate for the cold temps. I was able to net one and move it to another pond when I believed they weren't doing much. I still don't believe they are dong much in the trout pond unless they are feeding below sight level however they must be eating some vegetation as they aren't interested in pellets I have thrown to them. Some growth but not a lot probably due to the cold water. Very spooky fish!

I will be adding some to my bass growout pond next spring that is going nuts with chara if I find a reliable supplier. I had one promise to bring me some this summer but he never showed up. I'll have to have Bill Cody the expert to advise me on how many. If I can get him out here to see the amount of vegetation.

If I could get my algae bloom back in the bass pond by reducing the chara I would be one happy camper! I was thinking of adding adult Talapia to reduce the filamentous algae too. Maybe get all the nutrients converted to phytoplankton?

My pond has grass carp. The former owner stocked them, and he was a firm believer in "more is better." He stocked eight grass carp in a 1/4 acre pond. Yes, that's right, 8 in a 1/4 acre pond. They're all still alive; all over 30"; and all skittish as all get out.
But what do they eat? I haven't a clue! My pond would be literally covered in chara by mid-July every year if I didn't use colorants and/or Cutrine or some other algaecide or aquatic herbicide. Large grass carp sure don't seem to like chara... or filamentous algae, for that matter.
My only hunch about the grass carps' diet? I think they may be rooting up cattails to get at the root, or newly emergent growth.
I would not stock them if I had the choice. I really don't think this species was all that thoroughly researched by the Federal government (when? back in the 60's/70's?) before their widespread use was okayed. I think perhaps the States that balked at okaying them were on the right track. After all, this is a fish that can live 50+ years in the wild, right? Maybe this is one of those rare cases when the sceintific types would be right if they had said: "More research is needed."
Okay, I'll say one good thing about my grass carp: I foul-hooked one on my fly rod a year ago February. What a wild fight! Alas, 30" grass carp and 5x tippet materials aren't well matched. The carp won easily after about three minutes. Been hoping for a rematch ever since!

I have 5 (triploid) GC in 9/10 acre. I also have no duckweed in the water (it will grow on mudflats or in the drain box where the fish can't get it), no FA to speak of, and no submerged plants except a small amount of floating leaf pond weed. I do have the nicest plankton bloom this year I've seen yet.

Am I pro-GC? Yes, with moderation. I probably could have gotten by with maybe 3 of them; I'm sure glad I didn't stock 10. Having hooked them several times and caught one this year, as well as having had several opportunities to shoot them (they will get within 2-3 feet of me if I feed pellets off the dock and lay down at the edge), I feel certain I can easily remove 1 or 2 when I want to.

Like Bruce, I think they're neat fish. They have this orange to green coloration when seen through the water that I think is what dinosaurs must have looked like. They eat some fish feed, but some day I'll eat some of them. And I love to watch them play follow the leader, when from 3 to all 5 of them swim around in a line.

Yes, yes

So much for "easy format" answering. But really, I didn't expect that anyone could give a yes or no answer.

So with (7) responses, I'll try to quantify, and correct me if I've incorrectly categorized your response.

Condello: Yes/Pro? (also a notable mention as one who likes to eat them)

Cody: No/Pro? (assuming the right situation)

ewest: No/??? (standard juris doctrate approach or existentialist view that the half-full glass is neither empty nor full)

DoubleD: Yes/Pro

CecilB: Yes/Pro

MLSmith: Yes*/Con (*did not intentionally stock)

Theo: Yes/Pro (but can't find his car keys)

That seems to be 5/7 that have the GC, and 5/7 who are "pro" GC with one unresponsive respondent.

EDIT:
With Lusk's response, that makes it 6/8 having GC, and 6/8 "pro" for GC with still one noncommittal.

Come on Sunil. What did you expect? We're a bunch of fishheads! :p

Currently use? Yes

For or against? For, for prevention of problems.

Grass carp are most effective when used as a prevention rather than a cure. As a prevention measure, they should be stocked at 1 to 2 fish per acre and rotated out every three years, i.e. old fish removed and new fish added. When employed in this manner, the pond owner can avoid the problems associated with overstocking grass carp (or stocking at the conventional recommended curative rates of 10 to 15 per acre) including de-nuding the pond, muddy water, and eating fish food pellets. Those traits do not happen in a preventive use....its not the grass carp's fault for that behavior, but those who recommend the high stocking rates.

When used in conjunction with Tilapia, complete chemical free control of the pond environment is easily achievable....and both are excellent eating.

For prevention of problems yes � if properly stocked.

We stocked four in a 2 acre pond the second year when chara and water primrose began, but turned out under stocked when bushy pondweed literally took over the pond the fourth year.

Todd Overton recommended that we add ten GC and we are beginning to see progress.

We were too conservative in stocking numbers and waited too long � best to seek a professional opinion in your particular case.

George Glazener
N.E. Texas � and 2 acre ponds

ML: Yes/Pro (with honorable mention for Tilapia)
GeorgeG: Yes/Pro

Totals:

Have GC - 8/10
Pro GC - 8/10 with one still on the fence

So it looks like the grass carp is running at about an 80% approval rating.

Grass Carp are usually an all or none proposition when it comes to weed control, either you have too many or not enough, happy mediums are hard to find. In our case the GC seems to have had very little effect on the pond weeds. We have milfoil, sago, coontail, stonewart, and what I think is crowsfeet in our pond (not to mention the duck weed, filmetous algea, and catails). We have around 60-75 GC in the pond. Right now we have scattered coontail growing off the bottom of the in 11 feet of water, we frequently have weeds growing all the way to the surface in 6-8 ft of water. Grass carp do have a preference for certain typs of weeds, coontail and milfoil just happen to be at the bottom of their preference list for edible plants.

Sunil :

Will try to clear up your view of my last post/vote of ????. I like to try to be clear about what I write.I tried to include the conditions in which I would use GC. See below.

No-- haven't needed them yet.
Yes--would not hesitate to use them under the right conditions.

I think this is less ????. A half full glass is just that, nither empty ,nor full. ewest

ewest, thanks for the clarification.

Shorty has GC, but I really can't tell if he's for or against them as they are not seeming to help his weed issues. We'll put him in the "pro" category.

Have GC: 9/11
Pro GC: 10/11

Put me in the very cautious pro GC category, LMB and weeds go together like milk and cookies.

1. Yes - 4 in a 2/3 acre pond.
2. No Qualification-My grass carp seem to discourage bg feeding. When I feed, the bg will eat only the first minute or two until the gc show up. In hindsight I wish I had waited to add grass carp until they became necessary. They do eat well, had some on Sunday. However, way to many bones for me.

I need something to control the filamentateous algae. Any comments on grass carp for that?

I understand Tilapia is out for up here, too cold in the winter.

Tuzz,

Don't look to grass carp for help on FA...if it is the only, only vegetable matter in the pond, then, maybe, maybe they would partake. In my ponds, they turn their noses up at FA.

yes are in pond at house and of course sell them I think it was 1,800 last year.

Yes and excellent comments so far. It makes me sick to here some of the recommendations out there. Even from DNR office diff answers. I get calls from one DNR office they seem to say less than I would given the situaiton another office seems to rec. more than double or triple what I suggest. So yes good solution for most weed probelms if stocked properly.

An additional point not mentioned is size. For years folks stocked higher numbers but of sizes less than 10 inches (bass food) We recommend less numbers but pay a little more for the 11-13 inch ones if you have bass greater than 14 inches.

Yes, I have them. 18 in 4A, and 3in .5A
Yes, I would reccomend them. I might have put too many in the 4A, but haven't had problems yet. I hooked one (about 5 lbs) recently on a fly rod
and had a great time trying to get him in until he got bored and broke the line.

No I would not recommend grass carp. In 1 acre pond stocked 3 in 2000 plus 10 more in 2003. In 5 acre pond stocked 15 in 2000 plus 50 more in 2003. The initial stocking did little to controll weeds. The latter stocking did have some effect on weed controll. As the grass carp age and grow bigger, their weed control ability greatly decreases. The grass carp grow fast and large, most of mine are in the 20# plus range. That is a lot of biomass for a fish that is extremely hard to catch. If you have any flowing water out of your pond, that is not gated, they will escape. In my experience you get about two years of semi weed controll then you have years of useless biomass in your pond. They are also hogs at the protein feeders.

We stocked 40 in our 8 acre lake at the initial stocking in 1992 at the recommendation of our fish supplier for weed-problem prevention. Well it certainly prevented any weed problems. As a matter of fact, it prevents practically all weed growth to this day. I would like to have some weed growth for the good of the lake, fish, and wildlife. We now remove all GC when caught or shocked up by the experts. To date that's only about 8 removed. They are about 20 lbs or so now and put up an incredible fight on a fly rod. We've only caught 2 that way, but it took about 30 minutes to land them. They are very skittish and difficult to get rid of or else maybe we just don't know how. If anyone has any good ideas, let me know. Another problem we have found is that GC eat a ton of fishfood. When the feeders go off, the GC are there just about as quickly as the BG. Seems like moderation in stocking is critical.