Pond Boss Forums INTRO Questions & Observations White amars (sp)

Can you catch these fish they get huge and are they any account for anything?

White amur--also known as grass carp, have been the topic of many discussions on this forum.

They like to eat rooted aquatic vegetation quite a bit. Filamentous algae not so much.

They have short guts and "squeeze" nutrients out of the plants, not really digesting the actual cellulose. Because of this, many nutrients are still available after defacation for promotion of algae blooms. If you were able to account for dry weight of plants before stocking white amur, then subtract dry weight of fish mass created, you would still find that almost all of the mass was available for plant production, just different kinds of plants, such as the dreaded filamentous algae.

They taste really good, in my opinion, but are difficult to capture because of their dietary preferences.

Bruce, are you sure you don't also have a Juris Doctrate?

After reading your eloquent post, I can't tell if you are for or against grass carp.

I think you are saying that the fecal matter of grass carp can cause other problems. If so, do you feel that the risk outweighs the benefits?.

Sunil, that's one of the best compliments you could have given me!

I'm a proponent of GC in small, clear ponds where you can get 'em back out if you have to. I personally have them in three of my ponds.

I'm scared to death of them in bigger ponds with poorer visibility. If you overstock be ready for problems! When they run out of food they'll root around like there's no tomorrow, they'll eat tons of pellets and have a nasty tendency to outlive the landowner!

Bruce,

That's why I always comment on here to folks about the stocking rates of GC. Many states, many fish sellers, recommend rates of 10 to 15 GC per acre. After a season in which they clean out the weeds, then they have to find something to eat. Bad news. It is much easier to add than subtract GC.

I put 2 in my small pond and I caught one the other day on a worm, I take it that may be a bad sign?

bc - your situation is telling me the pond is fairly new with very little ROOTED vegetation OR they have all good vegetation eaten and the worm was about the only thing that is currently palatable for these fish. If there were plenty of tasty weeds available you probably would not have caught the amur unless it was on the Atkins high protein diet.

bc,

Wondering why that is a bad sign? I've caught them on worms also and didn't think of it as a bad sign. Just about every freshwater fish I know of will eat a worm occasionally.

Personally, I think GC get inquisitive and nudge/mouth soft baits a lot without being really hungry for them. They often show up where I am fishing for BG and seem to check out the bait w/o much interest; they actually take the bait seriously a very small fraction of the time. Freaks out the BG and temporarily ruins the spot frequently (happened last night), though.

I have to really target them while casting the bait to get them on the line, as they are a very low-percentage bait taker.

Bruce, interesting about GC eating habits and the leftovers they spread in the pond for further plant 'problems'. Is this any different, from a digestive point of view, than any other fish? I guess my question is whether the digestive system of a GC is less efficient than other pond herbivores.

I would contest that what is left over from grass carp digestion process does not directly or indirectly encourage filamentous algae or macrophytic growth. We've seen grass carp enrourage planktonic algae growth, but that is exactly what we want for fish growth. Cellulose, being the major structural component of plant cell walls, is indigestible to all single-stomach animals, including fish. In addition, undigested cellulose, is not a readily available nutrient for direct uptake by plants. It must first degrade into basic nutrients.

I think that the efficiency of the grass carp digestion is interesting, and have read that they can grow to several hundred lbs in their native environment. They may be inefficient eaters, but most plant-eaters are inefficient. Consider the economic efficiency of grass carp in comparison with herbicides, labor, time, etc. The alternatives to grass carp may include chemicals and countless hours of mechanical removal which has to be repeated throughout the season and every year.

Grass carp are an integral part of some of our management programs. They help us to feel comfortable with fertilization programs where macrophytes already exist, and they improve the efficiency of fertilization programs.

I agree that grass carp can cause problems, but I also must insist that they are a valuable tool for pond and lake management when stocked responsibly.

Todd,

I agree....and when combined with Tilapia, that's a formidable pond management tool, which may be effective in breaking the unending expensive and questionable cycle of using chemicals in our ponds. The cycle I speak of is fertilize, use herbicides to kill weeds caused by fertilizers, use copper based products to kill algae caused in part by excess nutrients from fertilizer, use whatever products are available to help remove the muck caused by decaying plants which were caused by hebicides which were needed because of...well you get the picture.

If not break, at least bend the cycle...

Great comments! I have twenty yrs. experience with the sterile grass carp and have had no problems. Their life expectancy around here seems to be about 12-15 yrs. After 8 yrs. or so I'll lose 1 or 2 in the early spring. Main problem i've seen is pond owners who fail to add a few every couple of yrs to replace ones lost due to natural mortality.

I obviously am not saying that GC have no use in pond management, given the fact that three of my ponds have been stocked with them. I'm just concerned with the misconception that GC are a inexhaustable nutrient sink. The math is really simple and indisputable. The dry weight of your grass carp mass increase will be about what your plant weight dry decrease is. You can't make something from nothing...or nothing from something for that matter. If your twenty grass carp have a net annual weight increase of sixty pounds, and the fish are comprised of 75% water, then you have only "created" 15 pounds of mass from the nutrients digested from plant life. Try to explain to me how you can lose any more than 15 pounds of dry plant weight in the process. One exception to this rule is in ponds with good flow-through. If the plant biomass is occupied in smaller organisms, like single-celled algae then your pond is more likely to see a net decrease in biomass in a rain event by allowing nutrients to be ejected through your overflow.

I disagree. The system is not that cut and dry. Assume 1 grass carp gains 3 lbs in a single year. Your explanation would lead us to believe that the carp ate no more than the equivalent of 3 lbs dry weight vegetation to gain that 3 lbs. What happens to the dry weight of vegetation that has to sustain metabolism, immune system function, and to provide basic energy needs? That dry weight is burnt as fuel and not released back into the system. I don't know the numbers, but am positive that actual weight gain can only comprise a fraction of total dry weight eaten, even in consideration of dry weight not digested by fish. Assuming filamentous algae did not develop with grass carp present, even undigested plant material that degrades to nutrients and is reassimilated into vegetation and can be processed by grass carp again.

Todd,

Once again I agree...could I humbly ask you to comment on my "cycle" breaking approach outlined above.

It's what I'm doing in my experimental pond this year...Tilapia, grass carp, F1's (Tigres ), fatheads, CNBG, RES..no chemicals whatsoever, no artificial feeding whatsoever..what do you think the growth will be on the F1's compared to the standard pond?

Maybe I'm getting of topic, sorry if so. But it does tie into the value of grass carp and their ability to lessen the dependency on chemicals in our ponds.

The growth rates for your F1 bass should be better in the test pond with following assumptions:

Water visibility similar in both ponds
Bass stocking rate is equal in both ponds
Plankton bloom is similar in both ponds
Water quality similar in both ponds

The test pond SHOULD cycle nutrients to top end predators better than that of your standard pond. But you have HSB in the standard pond...no?

The best bass ponds we've surveyed have been those with natural plankton blooms and no history of vegetation problems. Those ponds weren't fed artificial pellets either, just had relatively constant conditions over time with good natural bloom. Interesting experiment.

Todd, you're right. Metabolic needs have to be met, the GC has to swim about and run it's various organ systems, immune system, etc. The difference between plant mass and GC mass is dissipated as heat energy. The water becomes a little warmer due to these functions taking place within the fish. My only contention is that even with this taken into account, don't you think that some of your clients have the perception that the GC eat the macrophytes and "poof", they're gone? Energy and mass interact in a closed system. The plant material just doesn't disappear. It becomes fish mass, plus, as you pointed out, heat energy, but then what? If you're lucky your pond moves nutrients out through the overflow, but besides that, you can account for every single calorie into a pond equaling every single calorie out. Which by the way, I guess we need to include fish harvest as an energy outflow. Still, let me be concise about my point. I am ONLY saying the following:

Any nutrients that pass OUT of a grass carp are at least temporarily available for creation of new plants.

I promise you, I am not indicting your use of grass carp in pond management. They work quite well in many circumstances but I would like to make this second statement:

People with ponds often believe that stocking grass carp will solve all of their vegetation problems. Sometimes these people need to be made aware of possible ramifications to this stocking, such as possible increase in simpler plant forms.

I've seen first hand in every single pond that grass carp have been stocked in there has been a decrease in Secchi readings. I have the data, and unless it's been coincidental and happened twenty times in a row, then pond owners should know all the facts.

I really respect Meadowlarks desire to challenge the status quo. Tried and true has application, but every pond is different and almost every pond owner has a slightly different take on what their goals are, so shouldn't the point to this forum be to allow each of us to rethink the things that we believe are hard and true facts? I'll bet that since signing onto Pond Boss forum the first time that I've reassessed a good 1/3 of the things that I believed. There are even a few things that I changed my mind about, then changed it again. That's what makes this so fun!

Todd,

What I meant by "standard" pond was the artificially fed, artificially fertilized, artificially weed controlled, artificially algae controlled, and artificially muck removed bass pond, whatever that is.

There's probably no such thing as a true "standard" pond, which is, in part, Bruce's point also.

Bruce,

I too have noticed decreased visibility in many ponds stocked with grass carp. In many cases this didn't hurt a thing as initial visibility was swimming pool clear, but in some cases I believe they encouraged turbid water. I believe as you do that pond owners should know the truth, the risks, the pros, and the cons before they make a move.

Maybe I just needed to argue about something, maybe it's the weather. Still we are on same channel, I believe.

Bruce, I really gotta agree with your last 3 sentences. I, along with Cecil and some others, was among the original posters on the previous PB website. I started off thinking I knew what I was doing and rapidly found out otherwise. I have been through several phases where I thought I finally "got it". At this point, I'm not sure I will ever "get it". Some of you guys are successfully challenging previous truisms. I'm starting to think again of the rate of change of change.

By the way...Did anyone see Theo's post on this thread? Theo said what I was trying to say, but about three hundred times better.

Then it just disappeared--just like all those macrophytes. Maybe it was a post by his cousin Stumpy Jack Gallus. It was billiant just the same.

And in case anyone cares, I can see the applewood smoke billowing out of my smoker right now, and what's inside? You guessed it! White amur.

For the Record and to get him off my back before the private message system breaks:

I 100% AGREE WITH BRUCE (AND SO DOES MY COUSIN STUMPY JACK) !

Hint: If you ever delete a five paragraph post that may be judged "eloquent," either do it quickly or save a copy to disk for future re-use.

Bruce,
Where do you think people with ponds get that notion?
I've seen many posts of warning to be cautious of certain people selling fish. They make their living selling fish not managing ponds.
IMO we should be advising pond owners to buy from reputable people like Overton rather than suggesting GC do more damage than good.
GC in the correct numbers have proven to be the ticket in many more ponds than are represented on this forum.

I'm all for trying new ideas. Ask my wife, she keeps a smile/smirk on her face watching me modify a brand new purchase to make it better!

I too have out of the box ideas for my ponds & have posted them here in the past looking for suggestions.

I am just cautious since so many pond owners come here looking for answers. Am I helping them when I go against the tried & true?

In our enthusiasm to make our ponds better it's too easy to promote our untried, untested ideas as a better way to unknowing new pond owners. We mean on harm, but could we cause harm? We know our ponds intimately but mostly we are shooting in the dark when our advise steers someone away from what has worked in thousands of ponds across this country.

Our experiences are based on a relatively small sampling of ponds. I just don't think it's smart to disparage what has been intensively studied & proven to work at numerous universities across the country over many years & in many many ponds whether it�s stocking GC, fertilizing, feeding, or any of the tried & true methods of pond management.

Please don't misunderstand; I like the posting of opinions & out of the box thinking! I've picked up on several things I will be trying. I've also learned allot from these posts.
Since so many are coming here for advise I just think we should be careful not to stray too far in the advise we give & save the experimenting to our ponds.
After all Bob Lusk along with Greg Grimes, Ewest, Tod & many other pond managers practice the tried & true every day.
I'm not trying to say you're giving advise to the masses in this thread, just felt this needed to be stated. Besides, it's just my opinion.

All that being said, Thanks for all your experimenting with your fisheries & sharing it here!!!

To all :

This thread is a classic !! While it contains good sound information and discussion from many on GC , that is not what makes it a classic . What makes it classic is the way it approaches pond mgt. and its basic conflict , which is indeed much like human nature and its basic conflict.

From the first day we started on this planet {and likewise from the day pond mgt. started} there was , is and continues to be a coflict between safety and proved results in the known vs. the need to learn and improve. Do we stay in the protection of our cave or cross over the hill to a better place and risk harm in the process.

As I stated on another thread the trick is to balance the two so that those who don't know the risks can make an "informed" decision to either take the risk or avoid them. Knowledge is the key yet if no one takes risk we can never gain knowledge. Many many concepts that were thought correct have been later proved wrong . An example is the belief that the world was flat. Are we all going to be explorers or are we going to stay at home. It takes both for the world to function . Explorers to advance the cause and the rest of society to support the effort. Nither are wrong , both are helpful , and are in fact necessary.

Most of us on this fourm are both explorers and stay at homers depending on the topic or area involved . The key is to be sure that those who don't know the risks learn them and make informed choices. The only way to do this is through discussion . I suggest that we all read and write with as much care and precision as possible and with warnings as necessary.

As an outside reader of the thread I don't think anyone was wrong in their position. It was clear from reading that CG are a good pond mgt. tool but that there exist misunderstandings in the pond public about their negatives including the limits on controlling plants . Both are right , nither are wrong. A job well done by all involved . This forum continues to amaze in its ability to further pond mgt. in its quest forward. ewest

ps: For the record I manage ponds for my family and for friends and clients , like many on the forum , but not for a living.