Re: Lake Hopatcong Grass Carp:
 

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?

Re: Lake Hopatcong Grass Carp:
 

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..........

Re: Lake Hopatcong Grass Carp:
 

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.

Re: Lake Hopatcong Grass Carp:
 

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?

Re: Lake Hopatcong Grass Carp:
 

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 ??

Re: Lake Hopatcong Grass Carp:
 

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.

Re: Lake Hopatcong Grass Carp:
 

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

Re: Lake Hopatcong Grass Carp:
 

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.

Re: Lake Hopatcong Grass Carp:
 

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

Re: Lake Hopatcong Grass Carp:
 

They were stocked in the canal, which flows into the Raritan.