Lake Hopatcong Grass Carp:

[AndyS]

Lake Hopatcong Commission and Foundation
is interested in stocking Grass Carp in Lake Hopatcong to control the weeds. Currently the regulations only allow lakes less than 10 acres in size and they have to have containment. Lake Hopatcong does not meet either of those requirements. They were advised of that. To allow the stocking of Grass Carp in Lake Hopatcong would require a change of regulations.

[MattK]

Why not try it in lake musconetcong first? Dont they eat pretty much every piece of plant life in the lake? Seems risky to start in hopatcong.

[thmyorke1]

What's wrong with the weeds in the first place? Doesn't it promote good health and a big supply at the bottom of the food chain?

Whatever they do, I just hope it's sterile grass carp.

[FASTEDDIE29]

That’s a bad idea!!! Plenty of fish to be had in the big pond. They should stick em in RV, MC or maybe the lower Raritan! My carp friends would absolutely love that idea!!! Weeds are great, the panfish need a place to hide from the predatory species like Hybrids, Walleye and ESOX!!!:cool:

[NJSquatch]

This has been a hot topic lately. The pleasure boaters and residents along shallow coves (crescent cove, landing channel, jefferson canals, etc) are all for it. If it was left up to them they would kill every weed in the lake. The weeds (especially the invasive milfoil)do a really good job of choking up boat props and water intakes which damages the boat engine.

The Local communities have been spending a ludicrous amount of money on weed harvesting the last couple of years. Fortunately a recent bill was passed that has $500k of dedicated state funds to "enhance" the lake. Most of this money will be spent on weed harvesting which is essentially the equivalent to mowing the lawn and not a long term solution.

The Lake Hopatcong Foundation is pushing the grass carp agenda based upon the successes had at Candlewood Lake in CT.

Weeds are very important in a fishes life cycle and it is unknown what the long term impact will be on a fishery.

The reality is something needs to be done to maintain the viability of the lake as a public resource for all.

I say do a test area in the back of one of these coves to measure the impacts. The grass carp is sterile and there would have to be alot stocked to eat even a fraction of the weeds in the lake.

[bunker dunker]

without them weeds those herring will have no place to hide

[akoop]

While I enjoy the lake for both fishing and recreational boating and have on numerous times had to stop to clear my prop and water intake from weeds I feel this is a very bad idea. The lake seems to have an extremely healthy population of fish of various species and is just improving every year. Why mess with it?

[NJSquatch]

Just like the No Anchoring proposal (introduced last year) this is being driven by folks with influence (i.e. $).

The fishing community will need to stay on top of this and be very vocal as it is being discussed. Complaining about it after the fact will do nothing.

Here are some articles on the topic:

http://www.hopatconglakeregionalnews.com/index.php/news/all-regions/lake-information/1002-lake-hopatcong-foundation-provides-informative-update-to-the-hopatcong-borough-council

http://www.njherald.com/20171107/hopatcong-fishes-for-weed-problem-solution

http://www.thejeffersonchronicle.com/hopatcong-mayor-suggests-using-carp-control-weeds-lake-hopatcong/

[Chrisper4694]

apparently grass carp introduction completely saved a popular bass lake up in Connecticut (candlewood lake) that's why they have this idea. Idk anything more about it but you can find info online. I'd rather have plant eating fish than chemicals like they do on some private lakes, that's all i know.

[Jigman13]

I'd like to know a couple of things:

How do they sterilize the grass carp?

Is it 100% effective in regards to sterilization? Bc we all know, nature finds a way...

What's the typical average life span of grass carp?

How many would they be introducing?

With lake hopatcong's expansiveness, measuring effectiveness would be extremely difficult unless stockings are done in designated areas and the fish are realistically trapped within the confines of their theoretical containment. Otherwise, you're just throwing fish in a massive water body with next to zero ways of managing and measuring effectiveness. The words "controlled study" come to mind.

[Eskimo]

.

Apparently this carp will be GMO: They will have three sets of chromosomes (triploid) and will be unable to reproduce in the lake.

They grow quite large and have some value as a sportfish.

https://4.bp.blogspot.com/-3W9MgIIY6uo/Vtr_GJ7thBI/AAAAAAAAbkQ/IBl1WkPztlw/s1600/z%2Bamur%2Bcarp%2Bcarps%2Bgrass%2Bflorida%2Bworld% 2Brecord%2Bbiggest%2Bfish%2Bever%2Bcaught%2Bbig%2B huge%2Bfishes%2Brecords%2Blargest%2Bmonster%2Bgiga ntic%2Bfishing%2Bgiant%2Bsize%2Bimages%2Bpictures% 2BIGFA%2Blb%2Bpound%2Bvideo%2B%2Bfreshwater%2Brive r.jpg

https://s-media-cache-ak0.pinimg.com/originals/78/67/a4/7867a40898af2e8126f89f83a3bf6efd.jpg

[Andrushkin33]

Sleep well my friends.

Couple of Russian buddies from Brooklyn and carp situation will be under control in no time.

Andre

[cosmo]

Introducing an "invasive species" of carp is concerning.

We need to protect those herring and provide the best habitat possible for them to flourish. The entire lake's ecosystem depends upon it. Less weeds, less herring and everything changes, and definitely NOT for the better.

As stated by several above. There is no control once a non-native fish is introduced to the lake. It is counter to every instinct I have as a fisherman.

Googling the topic, I found the following from a Michigan / Great Lakes study, which validates the "nature will find a way theory":

“In the mid-1980s, a grass carp sterilization program was put in place to reduce the risk of introduced fish reproducing and reaching nuisance levels that would result in detrimental impacts,” Herbst said. “The sterilization program has worked to some extent, but fertile fish are still being captured in locations where only sterile fish introduction is authorized.”

[Charlie B]

Better and safer than chemical treatment and less cost than harvesting. I would welcome it...Charlie

[AndyS]

How about stopping all the residents around the lake from using high phosphorous fertilizers that promote weed grow when it washes off their lawns into the lake. The 100 year old septic fields that surround that lake promote weed growth also.
Kill the weeds and all the herring will be gone. Small fish need weeds to hide in as they grow bigger. This idea is coming from a boating, not a fishing community.

[AndyS]

The water quality will go way down if all the weeds disappear.
The Musconetcong river that is fed by this lake will be toast !

[Drossi]

How about stopping all the residents around the lake from using high phosphorous fertilizers that promote weed grow when it washes off their lawns into the lake. The 100 year old septic fields that surround that lake promote weed growth also.
Kill the weeds and all the herring will be gone. Small fish need weeds to hide in as they grow bigger. This idea is coming from a boating, not a fishing community.

Ignore those, they can't be the cause! Been that way since the late 1970's. If they'd taken proper care with the environment the lake wouldn't have the week issue it does. Most boaters aren't fisherman so they won't care if ridding the lake of weeds by any means does damage to the bait fish or other fish populations.

[Chrisper4694]

check out the candlewood lake grass carp introduction. That is why they are considering this, because of the apparent success there. I'm no convinced one way or the other but if you want all the information check it out, that is what they are using as 'proof' it has validation.

[Hookmanski]

I think there are decent arguments on both sides, but I agree that introducing an invasive species into the lake isn't the best idea. I don't know if this would make much difference, but if they could ensure the carp can't reproduce before stocking them that would be the most ideal situation. It could work if they managed it correctly, but if there is no solid way to tell if a carp is going to be fertile or not, then I say don't stock them.

However, if they can be 100% sure they won't reproduce, it could possibly work. How many are they looking to stock? I feel like if you had around 30-50 large carp in there, they could eat some of the vegetation but may not have as big of an impact as say 200. That way some of the weeds could get eaten and some would remain. Kind of a compromise.

Now I'm no biologist here, just giving an idea that could possibly work, making the lake a little better for pleasure boaters while not having too much of an adverse effect on the life in the lake. But like I said, if they can't promise the carp will be sterile, then I'm definitely against it.

[NJSquatch]

What is a Triploid Grass Carp? http://www.dec.ny.gov/outdoor/7973.html

In 1983, US grass carp producers began production of a sterile (triploid) form of grass carp, mitigating the reproductive concerns associated with the diploid fish. Triploid grass carp are created through shocking grass carp eggs immediately after fertilization with either hot or cold water. This temperature shock results in the retention of an extra chromosome set, rendering the fish incapable of producing viable young. With the exception of this extra chromosome set, triploid grass carp are identical to their diploid counterparts. They can live 10 years and grow to 25 pounds.

Triploid grass carp have distinct feeding preferences, preferring tender, succulent plant species over those that are tough and fibrous. Triploid grass carp will not control emergent species such as cattail or bulrush or floating leaved species such as water shield or water lily. Even among preferred submergent plant species, selectivity and consumption rate varies widely according to a vast array of factors including water temperature, dissolved oxygen and presence or absence of attached algae.

Triploid grass carp are extremely potent plant consumers. If overstocked, they are capable of eradicating all plants from a pond for periods exceeding 10 years. Besides the obvious impact such complete plant removal will have on vegetation-dependent fish and wildlife, total devegetation of a pond can also result in the development of severe algae blooms, foul smells and an overall decline in water clarity. To minimize or prevent such adverse impacts, plant populations should be maintained at approximately 20-30% of the pond's surface area.

Due to various factors that impact triploid grass carp feeding, it is impossible to precisely predict the exact number of fish to stock to achieve the 20-30% plant coverage target. The only way to prevent excessive plant control is through use of an incremental approach. This approach involves the stocking of triploid grass carp at the stocking rates suggested below, followed by a two-year waiting period for the fish to achieve maximal control. Then, if needed, more fish are added in small increments at two-year intervals until plant populations are reduced to the 20-30% threshold.

Recommended Initial Triploid Grass Carp Stocking Rates
Average Plant Density / Stocking Rate (# of fish per acre)
Low Plant Density / 5 fish per acre
Medium Plant Density / 10 fish per acre
High Plant Density / 15 fish per acre

Lake hopatcong is around 2,500 acres with approximately 30-40% of that area being less than 15' where the weeds will grow.

[oelgnal1]

Triploid Inspection

The USFWS only provides the inspection and certification service to producers that want to cooperate, and participation is completely voluntary. All grass carp in an identified lot, offered for sale, will have been individually test inadvertent mixing of triploids and diploids and that numbers of fish are appropriate for the orders to be certified. The inspector will channelize (at a minimum) every tenth fish during the inspection of the 120-fish sample of alleged triploid grass carp. Any sample with a questionable monitor reading will also be channelized, and any questionable data resulting from channelization will be considered non-triploid. If all 120 fish tested are triploid, the inspection is complete. If a diploid is found in the course of testing the 120 fish sample, the lot fails certification. All fish in that lot must be retested, individually, by the producer, before another inspection of that lot of fish is rescheduled for certification inspection. ted by the producer using coulter counter techniques before a USFWS Triploid Grass Carp Inspection will be performed. The USFWS Inspection consists of a retesting by the producer, in the presence of the inspector, of 120 individuals randomly selected by the inspector from the identified lot of alleged 100 percent triploid grass carp. The inspector will view the group of fish that is to be certified, verifying that the group is isolated in a containment unit at least 100-ft. away from the production ponds.

This is the sampling that the USFWS does but isn't required, I for one believe that there can be natural reproduction. As previously noted that they have a life span of 10 yrs. I know of a body of water that still has them after 30 yrs. and I fish a lake that has had them for at least 15yrs. This lake hasn't had any weeds for the last ten yrs. with a dramatic reduction in the fish population. The fish population has also been affected by the cormorants but where there were a dozen or more some yrs. ago, now there night be a half dozen or less. Another observation is that when the weeds are gone, they will consume leaves and grass cuttings that fall into the water.
States control the stocking of the grass carp very tightly and my understanding is that they fear if the carp get out of the body of water, who knows where they will go and the harm they might do. With all of the invasive species out there do we really want another?

[Adrenalinerush]

Directed to no one in particular. Don't be so quick to condemn without understanding. Are hybrids naturally occurring? Don't they eat the herring? Ya, but they are fun to catch. These carp have been stocked successfully over and over and help manage weeds. Just saying..........

[saxmatt]

Directed to no one in particular. Don't be so quick to condemn without understanding. Are hybrids naturally occurring? Don't they eat the herring? Ya, but they are fun to catch. These carp have been stocked successfully over and over and help manage weeds. Just saying..........

Good point. I've also run into many anglers who don't know the difference between the many species of fish under the name "carp", whether it's the buffalo carp which is a native specises to the United States, common carp and mirror carp which have been in the US for almost 200 years and are in most bodies of water in NJ including lake Hopatcong, Asian carp which are an invasive species causing a problem in the Midwest and are completely unrelated to common carp and buffalo, and grass carp which are mainly vegetarians. Some people just see the word "carp" and get all worked up but have no idea what they are talking about.

[oelgnal1]

Since I made the previous post, I will comment. What you say is true about the hybrids but as long as the forage population is sufficient, everybody is happy but if anything should happen to the forage, that can be disastrous to the fishery (just take a step back and consider NO milfoil). I know of another 500 acre lake where herbicides were used to kill the milfoil, it worked but the alewife population was destroyed thus limiting fish size.
Although the grass carp may be a viable solution in some cases, people may go overboard with the stocking and put in too many carp to control the problem. In this area there are many man made lakes that may lack structure and the milfoil may be the only natural cover for fry, destroy that and you may have a big bowl with a declining fishery because the alewife fry have nowhere to hide. There are other solutions such as milfoil weevils that are indigenous to the area but they help to control the milfoil but not completely destroy it. This may not be the solution in lakes the size of Hopatcong or Candlewood (only started stocking GC a couple of years ago) but keep your eyes open and proceed with caution since it's next to impossible to put the genie back into the bottle (especially if some can reproduce). I'm sure many boaters and swimmers would love a weed free environment but is that good for aquatic life and fry?

[AndyS]

White Amur. Invasive Grass Carp seen going through the fish ladder on the Raritan river spring of 2017. So you want to put these fish where ??

[saxmatt]

White Amur. Invasive Grass Carp seen going through the fish ladder on the Raritan river spring of 2017. So you want to put these fish where ??

And what's your point? Grass carp have been in the canal and river for many years and both the forage fish population and gamefish population are thriving. There are still plenty of weeds as well, including just upstream of the dam where that picture was taken.

[thmyorke1]

And what's your point? Grass carp have been in the canal and river for many years and both the forage fish population and gamefish population are thriving. There are still plenty of weeds as well, including just upstream of the dam where that picture was taken.

I agree with there being plenty of weeds. Last summer numerous spots on the Raritan were populated with vegetation.

Hiwever I dont see much grass carp. I can usually spot the common carp that roam around clearly. I won't doubt grass carp are in there but I can't say at a high population

[saxmatt]

I agree with there being plenty of weeds. Last summer numerous spots on the Raritan were populated with vegetation.

Hiwever I dont see much grass carp. I can usually spot the common carp that roam around clearly. I won't doubt grass carp are in there but I can't say at a high population
I've only seen 2. There are a few in there but they are rare. They're definitely not spawning or you'd see more. They were stocked to control the weeds.

[thmyorke1]

I've only seen 2. There are a few in there but they are rare. They're definitely not spawning or you'd see more. They were stocked to control the weeds.

Stocked purposely in the Raritan? Or they swam their way down? I wonder where they were originally.

[saxmatt]

Stocked purposely in the Raritan? Or they swam their way down? I wonder where they were originally.
They were stocked in the canal, which flows into the Raritan.

[Lard Almighty]

I hope this doesn't happen. Grass carp destroyed the fishing on Lake Eufaula in Alabama several years ago, it was big news in bass fishing circles when it happened. Allegedly, the grass carp ate just about every weed in the place, and then got so desperate for food that they started hitting lures.

Spraying might be a better option; at least you can target some areas selectively with herbicide. You can't tell the grass carp to just stop eating when enough of the weeds are gone.

[FASTEDDIE29]

Oh no this is turning into a political debate!!! What the hell??? Hahaha!!!! When there were contests at least people posted pics of fish! Now we just have statements and opinions from a bunch of cranky fair weather fishermen!!! Oh boy!!!

Disclaimer; My statement isn’t directed at anyone in particular! I’m just telling da truth!!! Please don’t get offended and if you do, PISS OFF!!! LOL!!!!!

[AndyS]

Grass carp were not stocked in the canal, they escaped from some farm pond being used to keep down weed growth. Flooding has spread these fish out. As F&W stated, they can only be stocked with NO OUTLET waters. Small fish need weeds to hide in, grass carp eliminate all the weeds thus destroying the food chain.

[thmyorke1]

I haven't heard if any grass carp were put into the canal

I have read posts on the canal stating about chemicals used on the water to control vegetation (or insects, I forget which)

The whole Raritan and Delaware watershed ends up to the main stem; surely it's gonna get some foreign fish.

[zhitoman]

Grass carp do not spawn in our climates, its way too cold for them. Grass carp eat insects and small fish as well as weeds. Grass carp are more like lazy gigantic chub in their behavior and are nothing like asian or common carp. I say put at least at least 1000 juvenile grass carp in the lake. Half of them are not going to survive the predators anyway. Guys, stop being whiny little girls, grass carp are harmless to the environment, I grew up in Europe and dealt with grass carp more than any of you here. We use carrots and cherry tomatoes besides other baits to catch them, they are fun and they taste delicious.

[Adrenalinerush]

Grass carp do not spawn in our climates, its way too cold for them. Grass carp eat insects and small fish as well as weeds. Grass carp are more like lazy gigantic chub in their behavior and are nothing like asian or common carp. I say put at least at least 1000 juvenile grass carp in the lake. Half of them are not going to survive the predators anyway. Guys, stop being whiny little girls, grass carp are harmless to the environment, I grew up in Europe and dealt with grass carp more than any of you here. We use carrots and cherry tomatoes besides other baits to catch them, they are fun and they taste delicious.

I'm gonna have to try carrots and cherry tomatoes because I can't catch them on dough balls, thanks!

[oelgnal1]

Here is some info on different types of control.

The aquatic moth Acentria ephemerella, the water veneer moth, feeds upon and damages this water milfoil. It has been used as an agent of biological pest control against the plant in North America. The milfoil weevil (Euhrychiopsis lecontei) has also been used as biocontrol. Another method for biocontrol is Grass Carp, (one of the Asian Carp species) which have been bred as sterile, is sometimes released into affected areas, since these fish primarily feed on aquatic plants and have proven effective at controlling the spread. However, the carp prefer many native species to the milfoil and will usually decimate preferred species before eating the milfoil. In Washington State the success rate of Grass Carp has been less than expected. They were used in 98 lakes and 39 percent of them had no submerged plant life left after only a short time.

Since roughly 2000, hand-harvesting of invasive milfoils has shown much success as a management technique. Several organizations in the New England states have undertaken large scale, lake-wide hand-harvesting management programs with extremely successful results. Acknowledgment had to be made that it is impossible to completely eradicate the species once it is established. As a result, maintenance must be done once an infestation has been reduced to affordably controlled levels. Well trained divers with proper techniques have been able to effectively control and then maintain many lakes, especially in the Adirondack Park in Northern New York where chemicals, mechanical harvesters, and other disruptive and largely unsuccessful management techniques are banned. After only three years of hand harvesting in Saranac Lake the program was able to reduce the amount harvested from over 18 tons to just 800 pounds per year.

[AndyS]

They also said Snakeheads wouldn't make it through the cold winters in N.J., now look. I don't think anyone is whining, this is good information for all fishermen to know.

[thmyorke1]

They also said Snakeheads wouldn't make it through the cold winters in N.J., now look. I don't think anyone is whining, this is good information for all fishermen to know.

I think I picked this up from the North fisheries meeting, but some guys down south are a fan of the snakeheads, how they're not wrecking anything as believed.

Im not going to be putting any in my goldfish tank still. Snakeheads might not be a problem now but in the future they can in those southern waters.

Any reports of snakeheads in the raritan?

[Jigman13]

I think I picked this up from the North fisheries meeting, but some guys down south are a fan of the snakeheads, how they're not wrecking anything as believed.

Im not going to be putting any in my goldfish tank still. Snakeheads might not be a problem now but in the future they can in those southern waters.

Any reports of snakeheads in the raritan?

Not yet but in due time I'm sure. Id imagine they'd show up in the canal in Mercer county and make their way up slowly but surely.

[thmyorke1]

Not yet but in due time I'm sure. Id imagine they'd show up in the canal in Mercer county and make their way up slowly but surely.

I hear they prefer very still water. Are there any known rivers (that have good flow) that have a snakehead problem?

Any reports of them in the canal? I hear flatheads were in there.

[Jigman13]

I hear they prefer very still water. Are there any known rivers (that have good flow) that have a snakehead problem?

Any reports of them in the canal? I hear flatheads were in there.

Flatheads are in the canal and mainstem. I caught a 9lb flatty 2 or 3 yrs ago in the mainstem. I've also seen carcasses of 20+ lbers tossed in the woods along the towpath

[AndyS]

Biologists look at Flatheads, Grass Carp and Snakeheads not by the day or week, they look at impacts 5,10, 20+ more years down the road.
What may seem fine today may not be so good 15 years from now, I give them due credit for looking at things this way. There is no crystal ball that tells the future but they seem to have a good understanding and how all wildlife interacts.

[cosmo]

The phosphorous in the fertilizers needs to be addressed. That is a root cause to the weed issue, and should be part of the solution. Just want to say that first.

The sterilization process is to treat fertilized grass carp eggs with heat or cold to make them sterile. That makes their chromosomes triple instead of double, which prevents normal cell meiosis. Insert some science class facts but for us they then grow up sterile. The National F&W site reviews testing of the fish and states that triploid fish will never become diploid, meaning they can never reproduce. It refutes a study in Michigan where supposedly the grass carp reproduced over time. (Not sure what to believe there)

So this would then become a conservation management issue. And that makes me uncomfortable too, since we have seen time and again an inability to properly manage programs consistently in NJ. Leaders change, budgets are cut, inconsistent efforts and results.

Patience is what is required in this type of stocking program! Introduce a small number of carp. Observe their impact for 2 years. Then introduce some more. 2 years later, measure results. And repeat until optimum stocking to lake habitat is achieved.

But I don't see that happening. The worry would be impatience to start, resulting in over stocking for maximum immediate results. The carp clear the coves. Boaters are happy.

Then the carp need more to eat. And keep eating. And we lose the weed cover for the bait fish. And the lake dies. Or at least the lake ceases to be the desirable fishing destination it has become.

We have one of the best fisheries in the state. Why risk that?

[NJSquatch]

What concerns me is a resident taking matters into their own hands and stocking the fish themselves or even stocking the wrong one!