Pros and Cons of Grass Carp

It was suggested to me that I post this question to the Forum, so it here goes.

I just got some fish stocked into my pond to replenish it a bit, and while he was there, the fish supplier was really putting the bite on me to try Grass Carp to control my weeds. I have a pond about three acres in size and that means a lot of chemicals to use for weed control. I've been reluctant to try Grass Carp because of some of the posts and periodicals I've read about them wiping out all of the vegetation, muddying the water, and their fecal waste. Yet, they sound like a good alternative to $600 worth of chemicals each year, as long as I can have a healthy balance in my pond.

So, can anyone give me the pros and cons of Grass Carp through their experiences and how many should a novice safely place in their pond per surface acre to start out with? Thanks. Maybe you can help me make a decision.

I have had two different ponds and placed grass carp in each - have had no problems at all other than they keep vegitation down. No muddy water, etc. They do grow rather large after a few years and I have been told the smaller, younger ones are more active in weed control - however, mine have been in four years now and are probably all between 15-25 lbs, and they have continued to keep my weeds under control. I have nothing bad to say about them.

Cons...1. it is usually an all or nothing solution. I do not want vegetation in my ponds we are making for bream/bass and fertilizing. If you want some vegetation try fewer than recommend and you might see some value, but usually will do little or wipe it out (good thing to me)
2. they love fish food, will eat food intended for sportfish.
3. if stocked too small can easily escape over spillway and end up as expensive bass food.

Pros...1. They will save tons in weed treatments.
2. Do not muddy ponds, golf couses stock 30/acre and still do not have muddy ponds, this comes from the name of grass carp b/c common carp do muddy pond, really these are white amur.

Stock at a rate of 5-15/acre. You may want to try only 5 and see what happens. Make sure they are 11-13 inches if you have bass 16 inches or better or other large predators.

per Gregs post, it is funny but I have never had the carp eat any of my feed - I run two feeders and the bass/bluegill eat it but never the grass carp - I also still have plenty of cover in my lake - seems my carp just keep the weeds in control

I wish that was the case. I have clients complaining about the carp. I guess they forgot about how bad the lake looked prior to their stocking. Tim, do you see the Carp? What brand feed are you using? I have only had luck with aquamax 600 with the carp not eating it, but most pondowenrs don't want to spend that much on the feed.

Greg Yes I see the carp on a regular basis - usually in the shallow water and running in groups - I use Purina fish chow - been feeding four years and have yet to see a carp at the feeder - I think I have around 15-20 carp in an 8 acre lake. My bluegill and catfish hit the feed so hard and fast when it comes out of the feeders that nothing else has much of a chance.

Thanks Greg and Tim for your input. I appreciate it.

Question for 'ya. In a worse case scenario where the Grass Carp wipe out your vegatation, does that hurt your fishing or the spawn of forage fish? If so, or if there is a wipe-out, what do you do? I hear these fish are a nothing at all or complete eradication proposition.

I am thinking of initally stocking 10-12 fish in my pond to shoot for a 70-80% control of my weeds. Is that possible?

Again, if there are others out there who would like to share their experiences, I would appreciate them before I make the commitment. As always, it is the pondowner's final decision and responsibility to take the action they want. I'm just looking for the Pros and Cons. Please let me hear from you. Thanks.

Can Grass Carp be caught on hook and line using some type of bait? Or is the only way to remove them by trapping or bow fishing? I've gone back thru many previous posts on Grass Carp but haven't really seen what type of weeds they control..other than they can't do cattails and are not really fond of alge. Is Curlyleaf Pondweed one of their prefered food items?

Greg- what were the main complaints about the carp from your clients?

Thanx,
Dan

Dan I have never caught one but have been told that a corn flakes mixture with Big Red soda is a good option (go figure!) Never had them hit live bait or any type of catfish bait like liver, stink bait, etc. Shotgun would work.

We stocked 50 sterile Grass Carp in our 8 acre lake because of problems incurred afer the lake was drained for a long period of time. They do a great job of removing and keeping the vegetation to a minimum. The best part is having one hit your ultra light spinning gear while trying to catch pan fish! They have taken everything from bitsy bugs to rooster tails, I know they are not known to strike those lures normally, but ours do. I do not regularly fish for them as a target because of the their place on the pond cleaning team. I had a hard time explaining to my son that the neighbors do not want to see the biggest fish in the lake on the end of his line. They do get pretty big, and there are several different baits that will attract them.
In NC only sterile carp can be purchased, not sure what your state laws are but if you're worried about overpopulation I would recommend that route. Another idea that we used was to add them in stages.

50 times three posts....Thats 150 grass carp.
HEHE

From my numerous experiences with g.carp, I've concluded not all g.carp are created equal. As in people, many of these individuals have eating preferences, but most prefer the softer leafy plants. Tougher leafed and stemmy plants are selected last in eating preferences. A few large grass carp when all preferable food is gone, will eat cattails but probably not enough to control large expanses of cattails. I had a fish hatchery person tell me that they pulled a complete cattail leaf from the mouth of a large amur.

Some filamentous algae species taste and have better texture to g.carp than others. Thus some people get limited algae control based on algae types, fish preferences & number of fish stocked. Generally high numbers of fish per acre are required to get any filamentous algae control. Its a crap shoot as to if you get fish that prefer algae or have unusual tastes or food preferences.

Some g.carp like fish food better than others. If plenty of palatable weeds are available, then most do not spend a lot of time eating pellets. Fish Pellet brand and flavor may have important considerations here also.

Curleyleaf pondweed is not a preferred food due to the turions (winter buds) produced by the c.l.pondweed. Turions are hard and unpalatable to amur. Amur prefer softer grassier mild flavored foods.

Most often,, food type, texture and flavor determines how many g.carp are needed per acre. And again I'm convinced some individuals are not aggressive vegetarians but most are. There is variety and variation in every species.

Put 25 in my 3 acre pond and am having no turbitity issues....I think if you have some of the non-favorite food types in your pond the ratio will need to be higher...They will eat to survive and it is a matter of putting enough in to get your desired result..They do work though

Dan,
I meant that the complaint was about the grass carp eating the fish food. Other than that few complaints one established in proper numbers. I do have filamentous algae popup in the spring even with grass carp.

Mark, I have never been able to acheive partial control. Like I said either all or nothing and I prefer nothing in Southern Ponds and do not see a problem with fry survival. We try to encourage artifical cover to provide a refuge rather than weeds. ALso someone mentioned buying triploids. They are required to be triploid in GA ( my license is $236 b/c they are considered exotic species) but not in AL. The reason is in case they escape they could possible reproduce in the creeks. They will however not reproduce in ponds even if diploids.

I think they are required to be triploid every where, at least every where that I have heard of. If they escaped and reproduced it would be that all or nothing managment on natural lakes. Currently the big head carp is moving up the missisppi river, I think it is as far north as Illinois now. The civilian corp of engineers installed and electric fish barrier on the channel between the river and lake Huron, for fear of them entering the great lakes.
With out triploid g.carp, this could easily happen with them too.

How do G.Carp work against eurasian millfoil?

I've used g.carp only twice against e.milfoil; eradicated it both times which may not be a good thing. Now both ponds are palgued with unwanted plankton blooms. Higher densities of g.carp were required. E.milfoil is pretty stemmy and not real leafy thus g.carp have to be crowded to get them to eat enough of it to make a big impact.

I think a better solution is to chemically kill milfoil, replant a beneficial vegetation and when it then becomes unmanagable use g.carp at low densities to thin but not eliminate the native less invasive, beneficial vegetation.

My pond is very close to a millfoil infested ditch, and Im sure ducks and racoons will transfer it over and over again. I'm afraid that chemical treatment would cost too much for 8 acres, are there other control methods?

I am interested in putting grass carp into my 2 acrte pond. Water clarity is a big issue as the pond is used for swimming. the weeds I am having trouble with are a type of pond weed and Chara or nitella -I'm not sure which. Will they be a help for any or all of these? How many should I put in a pond that size and what species are best?

I was recently told that triploid grass carp would eat common pond weed and naiad (sp.?) in my pond in Western PA.

Can anyone verify that for me?

This seems like a good topic line to pose that question.

Thanks.

Sunil and Steve,
Do you like Sirloin Steak? Well to a grass carp native pondweed and naiad is top choice. Chara and Nitella are also fairly desired. If you want total control stock 10-15/acre. Make sure to stock them big enough to survie bass predation. 8 inch grass carp is easy meal for even a 14 inch bass.

Thanks Greg.

I've got to do some work to gate off my inlet and outlet which is in progress. Then I'm going to add in some triploid grass carp.

I'd start out slowly on the carp. We put 7 approx. 12 inches long in my neighbors 1 acre pond last summer. It was weed infested. This year there are no weeds. Thus, no hiding place for baby fish. I think the State of Texas allows 10 per acre. That has turned out to be too many. However, I have also read that they have a fairly high mortality rate so we're not sure what the future will bring.

Dave, my pond is around 6-7 acres. I'm most likely going to start w/ only (10) grass carp. I know that sounds low.

I don't want total elimination of the weeds.

From there, I'll gauge progress and adjust as necessary.

Thanks for the input.

Tim K. ,
What kind of vegetation do you have in your ponds that the carp eat? Was it eurasian milfoil?
Dave Davidson, what kind of weeds were in your neighbor's one acre pond?
I have a milfoil problem I'm going to address with grass carp . Can't afford chemicals, and raking it out is not practical.
When is the best time of year to stock 11-13" grass carp? Would it hurt to stock them in the fall in North Central Texas?
Thanks in advance.

We were dealing with American pondweed and some millfoil.

BTW, I just bought that 71 acre place. It is contigous to my original place. Now I have to get my butt over there and spray some small willows and catch a bunch of 10 inch bass. We stocked the grass carp in the summer. They have really clobbered the vegetation. I caught one of them on a small hook with a piece of night crawler the other day. I guess they are getting hungry. I was bluegill fishing and got a heckuva fight on my ultralight. It was about 18 inches long and had doubled it's size in a year. They definitely work.