I bought a property in Central Virginia that has a 3.5 acre pond that I'm still learning about as I try to learn more about pond management -- I'm definitely a novice.

I'm told the pond was stocked. But, I can get little information about how.

I have noticed that I have 6 pretty large grass carp. When I put out food pellets for the blue gills the carp come in like vacuum cleaners and gulp down everything they can. Maybe not surprising, I don't have a vegetation problem. But, are these number of grass carp too many for a 3.5 acre pond?

Hey Love2Fish, sounds like a nice place and would love to see pictures!

On the GC, I stocked a recommended 8 in a 2 acre pond 2 years ago to help control Coontail and Chara so I don't think 6 is overkill in 3.5, but are you sure that's all you have?

I too no longer have the vegetation issues/problems I once did but the GC are now HUGE! But I also don't know if they're eating pellets. If I knew they were I think I'd want them out but other than that I don't know if they're causing any problems.

There should be some experts chiming in soon.

No, it's not too many but the large carp don't do that much for plant control. It sounds like you have some freeloaders that need to be eliminated. I have found that, like other facets of life, a shotgun works wonders in problem solving.

You'll have to learn about the fish population by observing and angling. The most important part will be to keep a log. Over time, you should have a pretty good idea of where you stand.

lol...you're funny Dave!

Can't be sure that 6 is all that I have. But, seems like most days I can identify 6 that come in when I put out pellets. These things swarm in like a school of sharks and get more than their share of the food I put out.

I just want to be careful not to trade off using more food pellets or dealing with pond vegetation.

I see if I can post some picture in the right place when I figure this out. Thanks.

Dave, if that's the case then do they provide any other benefit besides target practice?

I have read on this forum that it is best to ladder stock them. Take out the older ones because the young ones are willing to eat more to grow. Also, it has been mentioned, if you want to discourage them from eating pellets, whether they are old or young, catch them on a pellet (stuby steve) so they will learn to avoid them and not waste your feed.

I too have a love/hate relationship w/my grass carp. They are amusing, intelligent fish, but they are relentless at gobbling feed. I've caught them and shot them w/.22 birdshot,but they still show up to feed and consume way too much food. I am beginning to feel the same way about turtles. At first, I enjoyed watching them at feeding time. Now, I am getting too many.

GC can live up to 25 years...

If it was my pond and you don't have a submerged plant problem I would not touch them. We have had this discussion in the past whether large GC eat as much as young GC. In the past I have had grass carp roughly 3 1/2 feet long and looked to be in the range of 20 to 30 lbs, and it takes calories to make a fish that size go. I watched those large carp eat and they didn't seem any less vigorous then new grass carp I put in last year and this year. I talked to a guy at a fish hatchery that said he saw a large crass carp rip out a large cattail like a bull dog.

I used to feed pellets to my fish and the very large grass carp were hogging there share of food and so again their feeding wasn't slowing down.

Actually, large GC don't take as many calories because they only leisurely cruise and float with a slower metabolism, have no fear of being pestered by other fish anymore, and eat less because growth has slowed along with active swimming/foraging. Smaller GC eat far more to grow, avoid predators, have a higher metabolic rate and are constantly actively swimming looking for food.

You have to consider calories per pound. you could have a one pound fish taking in 2000 calories or a 10 lb fish taking in 2000 calories. Why would one want to get rid of the larger fish? This is where the discussion ended before.

But I'd wager to bet that the younger GC need more calories per pound than the older ones (growing, swimming more vigorously, maybe trying to avoid predators, etc.)

I tend to think of young GC just like teenagers, a teenager will eat more food per pound of body weight than a 70 year old will.

Managing a pond is about controlling the biomass in the pond, and getting to work the most effeciently.

If a 30# 20 year old GC will control the weeds, why not replace it with a 10#, 4 year old fish that eats the same amount of weeds? That leaves 20# of biomass that you can have in reserve for the other fish to grow (or as a buffer against an O2 crash), or utilize it with other, possibly more desireable fish in the pond.

I don't know, at 51 I think I eat just as much as they do, it's just that the teenagers still have a thing called metabolism where I just seem to keep adding to the 'bio bodymass'

With all things being equal, for me it comes down to expense and ascetics. Why replace perfectly good very large fish that the great grandkids are thrilled to see and that also keeps the submerged plants in control, plus the expense of smaller replacement grass carp that eat no more total plant vegetation then their larger cousins.

Esshup I'm sure you have an argument for the biomass. But it would seem to me that biomass would have to be measured in a pond's water volume by the kinds of food available. Vegetation for grass carp, algae for the KOI and Israeli carp, minnows/frogs/bugs for predators and veg.and minnows for channel catfish. At long as the large GC weren't eating what the bass were eating the biomass could become larger then just a predator pond alone. Until my total winter fish kill five years ago I had this kind of pond. I'm sure I raised eyebrows when I mentioned the number and size fish in my one acre pond which must have been off the chart when figuring biomass but the reason was, I believe, I was utilizing every food source almost possible for a pond.

The only real benefits I see of a huge grass carp: Viewing and fishing. They're kinda nice to look at while gobbling pellets. If you catch one, it's about like roping a freight train.

I look at available food as being only one limiting factor of supportable biomass. I think available oxygen is far more critical at any given moment.

I wanted to take a few out out of my pond. I bought a prong on the internet, fastened it to a 10 foot steel shaft and speared a large GC. It pulled the spear out of my hands. It was that strong. Maybe I was just weak. The GC are smart but I finally speared another one that it also pulled the spear our of my hands. I did find the spear both time laying on the bottom and it didn't kill either GC.

A couple of years ago we shocked our 2 acre pond and a huge ~20-30 lb GC emerged and nearly upset the boat.
Due to 2011 fish kill we did not have a clue if any survived - never saw one ever - not at feeder positively!
It had to be eating something to grow that large, but our newly stocked GC gorge on fish food.
I'm soon going to give them a survival lesson with a Stubby or pellet fly! Don't ever release one after capture - they are too smart to ever hit another pellet type fly.
They are a hoot to catch on a fly rod!
George

John, a detachable head spear might do the trick. It is what is used when spearfishing large fish underwater. The head has wings held back by a retaining ring. When the head penetrates the fish, the wings flip out, then the head detaches from the spear and is held by a strong steel cable. This lets the shaft flex independently from the fish. Rope attached to spear. Pull fish in with rope.

Gig heads are usually reserved for small fish because of the problem you describe.

John, there is no question you enjoy your waters and put a lot of thought into managing it, yet I also have to say the things you have talked of doing, and work well for you, are not the way most people want to approach the same situation and some of the theories you used were far from accurate scientifically speaking. I enjoy your posts and I am sure some would enjoy the variety of fish species you have used in your pond. I and others here have only commented when we knew something theorized, was factually inaccurate as far as how end results were attained or what fish target as food.

Most people stock GC for vegetation control, and there is no actual debate in the fact that younger, growing fish burn and consume more plants and calories per day than an older, larger fish. Personal reasons for wanting that are just that, personal, purely subjective reasons.

You just described carrying capacity, Sparky

Yep!