Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Grass Carp

I'm sure there is a pecking order for what type of vegatation Grss Carp prefer. Does anyone have a such a list?

IIRC this has been posted on the forum and Bob has published it in a Pond Boss issue...someone with better archiving skills than I might be able to help guide you. Have you tried a forum search on Grass Carp?

Washington state has a listing on what GC prefer for the most part.

http://www.ecy.wa.gov/programs/wq/plants/management/aqua024.html

Thanks for the Washington State article. It was what I figured, they will eat what ever is available, but do have preferences. Reading between the lines, I would say it is hard to acheive every variable. Some lakes have FA, Millfoil, Hydrilla and Lilies, while another has coontail, bushy pondweed, and parrott feather while another might have all of the above.

I was hoping one of our lake managers from Texas or the SE might know from experience, which plants in our East Texas lakes tends to go first and so on down the line.

Specifically, I have a 25 acre lake that is 30% to 40% covered in Coontail and it has 160 Grass Carp that have barely made a dent in the lake over the past 2 years. We just added an additional 100 Grass Carp, which gives us the maximum by law. There is virtually no other plant life other than coontail. I am in great hopes that we have a lake with 10% coontail.

Regarding coontail and GC, the literature is variable on the preference for coontail. Some in FL consider contail a preferred food where as in the Northwest US coontail is variably preferred and in New Zealand it it 13th on the list below Vallisneria but preferreed over milfoil. Size of fish seems to affect how much coontal is eaten. Some selective browsing of other vegetation in your lake could be occuring. When those plants are eliminated the GC will likely start eating more coontail. It does take some time usually 3-4 years to see the ultimate ability and impact of GC on the weed community, esp for waters dominated by less palatable weeds. I predict that in 3 years (2013)your lake will be denuded and turbid from suspended silt and you will be back asking how to remove grass carp. I hope I am wrong. I've seen 10 GC per acre denude a heavy infestation of milfoil. Others will definately have opinions which are welcome. Keep us posted on the progress of your coontail and GC.

I have a 25-30 acre lake with 9 per acre in it with 75% coverage of coontail. This is the second year they have been in with no results really.

Bill i trust your knowledge just like others on here but I sure don't see no results on year 2 so far. There is nothing else in the lake but coontail and FA.

So your saying year 3 is the magice number. I tell you I wouldn't mind a muddy water right now when you can't even fish the lake this year really. There never seems to be that happy medium.

I have a theory that may be worth just about what you are paying for it.

I think of herbivores such as Grass Carp like I do cattle and/or deer. A grazer prefers tender tips of plants and will pretty well avoid tough grasses and mature plant life. If they get hungry enough, all bets are off and they will eat anything that grows. This year, at least in my neighborhood, has been an anomoly. Due to amazingly quick winter to spring weather changes, plant life erupted and everything got a growth spurt. I have wheat that is 5 ft tall and basically inedible by grazers.

I don't believe that you can judge anything by this years results.

I have seen the same thing Dave and agree...

chadwickz, Year 3 may not be the magic number. In your case it may take 3-4 yrs to see the benefit of the GC. If you don't see any benefit after 4 years, then you may need to add several more fish per acre. Consider maybe try spot treating the coontail early in the year or during a low or decrease in the population. Knocking it back and giving the GC a chance to catch up on the growth. Do you feed pellets to the fish? Are GC eating pellets instead of weeds? Also are you sure you stocked big enough GC that the larger bass did not eat a lot of them. A 9"-10" GC is not very big in body cross section - essentially round. An 18"-20" bsss can easily eat a 10" GC. Maybe some of your GC were food for big bass?

Bill, 12"+ when they were stocked. I don't feed either. My luck is they might control it after 4 yrs will all that lost fishing but then by that time be huge and not eat it but maybe for one year then stop eating altogether. For now Grass Carp and coontail to me don't mix. Next spring if they don't handle it I will consider them probably a bad investment and probably hit the lake with whitecap. The lost fishing year after year is the main point here. To me they are not a realistic option for a coontail problem if you have to wait that long for good results. The way everyone talks though it doesn't take but 2 yrs. Thats why we tried them to begin with.

I stocked about 5 carp in my pond after it filled up. Pondweed exploded and I never saw the grass carp. The pondweed never seemed to go away. After a couple years I was getting frustrated. Guys here told me that I should see the carp. Maybe something got them. So I went out and bought 10 more. Everyone said they should mow down that pondweed and that I would see the results the next spring. This is the next spring and I see a lot of sandy bottom that I normally did not see. End of May to first of June is when the pondweed really takes off. We will see if they have a handle on it but right now it looks like they may. I have only seen 2 and they are big torpedos now. 25 acres is a lot of water and I know how frustrating it is waiting to go fishing. My patience has been that I wanted to do this chemical free. I can always fish topwater baits !!!

I have been asking around for the list of prefered plants GC like in preference order. and guess what. I found it.

Coontail is #9 on the list.

http://www.aquanic.org/publicat/usda_rac/efs/srac/3600fs.pdf



Thanks

Steve

That was some interesting reading on grass carp. Interesting that small grass carp will eat FA. Too bad you cannot stock them and then get them out the same year...lol !!

Out here in Cali we don't even bother with Grass Carp. Too many hoops and regulations just to get them here, and no one wants to raise them. We use Hybrid Carp. I just planted 200 6-9" for a 1+ acre over 60% Coontail infestation. Good thing about our carp, they eat the soft stem stuff up, and the algae. Of course I am going to hand pull and rake, because Coontail really does not have a root system. Help get the carp over the hump and start knocking it down.

Bad thing is, they are bottom suckers also. Going to increase turbidity. And no, Grass Carp traditionally are not bottom feeders. And no, they will not increase turbidity. That is for the Hybrids, Isreal and Koi, the Commons. Completely different species and feeding habits than the Amur.

Don't count me on the others on here list please.

www.wvu.edu/~agexten/aquaculture/Carpbroc1.pdf

Here is some info from a real Pond Doctor. A guy with Ph.D. after his name at an aquaculture dept of a major university.

Salex, the reason those carp barely made a dent is you stocked at too low of rate. With the add you are now up to 10 per acre which should be enough for 40% Coontail infestation. However, I would also manually remove whatever I could at first, because there is a point where the coontail just explodes and does not stay in line with stocking rates. If you are at the legal limit you need to help those fish get over the hump, once they do it will be reduced anually. And the water should not be turbid. If you pull coontail slowly it usually just comes up from the bottom, where the carp are not that effective. Drag that mass out and let it die in the sun.

Chad, you are just not going to make it. 9 per acre with 75% coverage is so far below needed stocking rates it is just never going to happen. Never. I'd almost triple that if I could, get near 25 per. Muddy water is not a concern, because they are not really a turbid fish. And time is irrelavant. Could be 3 years, could be 30. And you won't see anything. That stocking rate is not even keeping up with the new growth. It is not going to be some magic number of years either. Same as Salex, you either bump the rates, and mechanical or herbicide to get the fish over the hump as I say. When they actually start knocking it down it slowly gets reduced. And Coontail will get eaten by Grass Carp, it is something they do inhale.

Mike, 5 Carp? What am I missing here? Is your pond 1/4 acre? It takes a lot of fish, soemtimes 20 per just to get going. And you are best off starting with bigger fish 12" or so. They have a lot better survival rate and are entering thier peak eating years.

Grass Carp will eat what they want, no doubt. And so many people have posted they are less than impressed with the results. Problem is they don't come with instruction manuals. And people put them in and hope for the best.

Here are some thoughts:

Plant them for soft material, pondweed, hydrilla, elodea, coontail.

Don't bother with hard stemmed stuff, cattails, rushes, lilies as they can't eat it.

Sometimes they will avoid something you want them to eat, Eurasian Milfoil is one of those that sometimes good, sometimes no good.

Stocking rates and proper size are key, people say they either work or don't work. What is really happening is they either get over the hump and start taking stuff down, or they can't keep up.

Don't get them for algae, duckweed or azolla. And they are not turbid fish, they just don't roil around in the mud like common carp.

Sorry to be the bearer of bad news but just so much questionable info in this thread I decided to throw some known facts out here. Now, off to my coontail pond, where I will drag a little more out of the pond, and cull out 100 or more 3' and below bg. Like everyone else, this customer can't fish with coontail, who can?

Doesn't PHD stand for Piled High and Deeper?

PHD, Plumbing Hardware Dispatcher.

Pond Frog,

Great advise and information. What is the best way to mechanically remove it? Since 50% of the coontail is in 5' or less water, I think I could get some day labor guys to help. But what tools are best?

Are you thinking if we could get the 25 acre lake down to 20% or less infestation than the 260 grass carp might control the rest?

Today I was taking it out of 6 feet of water with a hard tine rake. Good part is once you get it off the bottom you can either pull it in hand over hand or drag it to a shore. The way I look at it is the more I mechanically or manually remove the closer I am to getting the carp to be more effective. And I planted 200 per acre. I can always seine them out later. If I had a bigger pond I would make a drag line and a 5 foot wide rake. Jenson has a Lake Rake that would also work. But you have to be careful as you can really grab some weight. My electric with 55 lbs of thrust comes to a dead stop trying to move too much. The stuff is real light once the water drains out. An old style grappling hook tossed way out and pulled it slow would work in some places. If you had some helpers you could knock down an acre a day. I think the objective is to lower ratio to get to point grass carp get ahead of it.

Yes. I know they eat it up. But with that stocking rate they should get on top of it pretty quick. I think you will be at least double of recommended guidelines. Overkill with carp is a faster end result. Inadequate stocking is a waste of time. I'm waiting for 5 months for ponds lowest level, and then I hit it hard manually. Then next Spring when it re-emerges. But I have over 60%.

That is an old link. You can get to the main site here
WVU Aquaculture Exension Service

That brochure can now be downloaded here: Herbicides and Grass Carp Can Control Pondweed

The site is maintained by Dr. Ken Semmens, and many of the papers available on the site have been written, or coordinated, by Dr. Ken. The entire staff of PhDs that I've worked with at WVU are all real great hands-on aquaculturists. The neat thing about them, particularly Dr. Ken, is that they are extremely responsive to WV residents. Just ask Todd about his fish flesh testing for pesticides through another Dr. Ken that Dr. Ken set him up with.

Ken

P.S. Cecil -- your belt feeder came from Dr. Ken.

What are the parental species of the hybrid carp used in CA?