NZ Mud-snail outbreak at PA Fish and Boat/Co-op Hatchery confirmed. Invasive NZ Mud-snails transmissible by stocking trout that ingested them.

[Fish Sticks]

I heard from a fellow Fly fisher that Benner and Pleasant gap were dealing with a new Zealand mud-snail outbreak and that depopulation of the fish in the hatchery was not taking place in efforts still be able to stock the trout eventually.

Alarmed, I called one of the above listed hatcheries and got a helpful PFBC employee and asked the following questions and got the following answers.

-Outbreak at Benner and PG?

Yes PFBC staff been trying to clean them out all summer without eradication.

- can trout move the mudsnails?

Yes was told trout eat NZ mud-snails and after an unkown amount of time poop them out alive where ever the are(in hatchery after a cleaning for snails or where they were stocked).

-since the outbreak have fish been stocked?

They answered yes but apparently only at a co-op hatchery that already has the mud snails (so this makes a 3rd hatchery now having the outbreak in total). They were not sure apparently which coop had the outbreak and received fish when I asked

-I asked has depopulation(killing/harvesting fish ) been considered to preventing stocking carriers of the snail given no successful eradication to date with intensive repetitive cleaning measures?

They said they were not sure but had no heard anything like that yet and they wouldn’t be the decision maker on that one and it would come from higher up.




If anyone has more information about which coop has the outbreak or this evolving threat please share. This is really concerning because Its sounds like there is a really significant risk of spread here if these stocked fish have mudsnails in their digestive system and get stocked. You can see how this can effect native and wild invasive trout in PA ……one harmful effect is they take out the macros.

NPS - Page In-Progress

Would hate to say bye to the green drakes, sulfurs, march browns, and have the native fish species suffer this loss in the name of hatcheries and stocked fish. Please update with information if you hear anything.

 

[Nocktavius]

I’ve said this before… I’m willing to bet nearly every instance of transmission they blamed on fly fisherman not cleaning their waders was due to this situation.

 

[Fish Sticks]

I’ve said this before… I’m willing to bet nearly every instance of transmission they blamed on fly fisherman not cleaning their waders was due to this situation.

I mean thats a valid question because there are hatcheries in the spring watershed which we know has em. Having a hatchery on a stream is never good for the ecosystem but it just seems like now that its an unmitigated disaster rasing stocked invasive trout in an area know to contain another transmissible invasive species that can be carried inside the first one. Invasive species within an invasive species, feel like i am in the movie inception.

With species loss/ active biodiversity crisis, recovering america’s wildlife act money on the way to help the sensitive species/ecosystems this could harm, and mounting research on dangers of stocked invasive species, surrounding states cleaning up their act to various degrees/going to science based fisheries management something has to change we need stocking reform badly.

 

[Cznymph]

I would be interested in knowing if the PFBC went through with the stocking scheduled for today from both Benner Spring and Pleasant Gap hatcheries. Almost all fall stockings from these two hatcheries had been postponed by a few weeks and looks like the majority of them begin today.

I’d really hope that the PFBC would do the right thing here ecologically and depopulate these hatcheries to ensure that the NZM have been removed. However, based on past practices, I doubt that is the case. Hence the limited information made public about the snail detection and the admission that the snails have yet to be removed.

A quick google search shows that snail infestations can be persistent, as in the case in several hatcheries. Below is a link for a news story regarding Montana hatcheries.

Snail infestation forces Montana hatchery to destroy most of its fish

For the second time in about two years, the Bluewater State Fish Hatchery is battling an invasion of New Zealand mud snails.

www.google.com

 

[Mike]

The hatchery discussed in the above article demonstrated the important general point that in some hatcheries around the country some sections are or could be isolated from others, which is an important consideration when considering this topic.

 

[silverfox]

I simply don't see how anything other than extreme protective measures to prevent the spread of AIS could be viewed as acceptable. You either explain to the public that you had to dispose of fish to prevent the spread of AIS, or you spread the AIS and explain to the public why you put the entire environment at risk in order to appease a subset of the angling public. This seems like a no-brainer to me.

 

[Fish Sticks]

Yea we have a lot of signs around the state about not spreading aquatic hitchhikers ( little irony there given what the great white fleet does). However, yes you gotta practice what you preach and if they release those fish its going to create a huge messaging issue further weakening invasive species mitigation efforts in PA in addition to spreading an extremely destructive AIS into possibly some of our highest priority conservation environments where the recovering americas wildlife act money is meant to be spent on.

Ultimately there will be accountability here the question is just to who and what wins out. They will either have to answer to a few angry anglers more concerned with catching fish than preventing an environmental disaster vs. the entire commonwealth of PA, US fish and wildlife, DCNR, and possibly who ever decides the apportionment of the Recovering America’s Wild life act money depending on what kind of steward of the money the commission is in their eyes.

 

[Schaefer406]

I heard from a fellow Fly fisher that Benner and Pleasant gap were dealing with a new Zealand mud-snail outbreak and that depopulation of the fish in the hatchery was not taking place in efforts still be able to stock the trout eventually.

Alarmed, I called one of the above listed hatcheries and got a helpful PFBC employee and asked the following questions and got the following answers.

-Outbreak at Benner and PG?

Yes PFBC staff been trying to clean them out all summer without eradication.

- can trout move the mudsnails?

Yes was told trout eat NZ mud-snails and after an unkown amount of time poop them out alive where ever the are(in hatchery after a cleaning for snails or where they were stocked).

-since the outbreak have fish been stocked?

They answered yes but apparently only at a co-op hatchery that already has the mud snails (so this makes a 3rd hatchery now having the outbreak in total). They were not sure apparently which coop had the outbreak and received fish when I asked

-I asked has depopulation(killing/harvesting fish ) been considered to preventing stocking carriers of the snail given no successful eradication to date with intensive repetitive cleaning measures?

They said they were not sure but had no heard anything like that yet and they wouldn’t be the decision maker on that one and it would come from higher up.




If anyone has more information about which coop has the outbreak or this evolving threat please share. This is really concerning because Its sounds like there is a really significant risk of spread here if these stocked fish have mudsnails in their digestive system and get stocked. You can see how this can effect native and wild invasive trout in PA ……one harmful effect is they take out the macros.

NPS - Page In-Progress

Would hate to say bye to the green drakes, sulfurs, march browns, and have the native fish species suffer this loss in the name of hatcheries and stocked fish. Please update with information if you hear anything.

If the PAFBC doesn't prevent the spread by not stocking all of these trout from the affected hatchery areas, I will never ever support them in any means ever again. Absolutely mind boggling to me that our state commission will not take any means necessary to prevent the spread of this invasive species just to stock rivers with pellet pigs for "recreational purposes". I do know that different sections of the hatchery may have "unaffected" fish, but how in the heck are they going to verify this? Take ever fish out one by one and investigate their poop and body?

 

[pcray1231]

If I were in charge, I'd say don't stock those fish this fall. Fall stockings may have to be pulled back a little, but take what you can from uninfested hatcheries. Buys some time.

As for the infested hatcheries. Don't kill the fish yet. There are likely efforts that can be taken to disinfect the hatcheries. Move fish to an empty raceway, clean an affected one. Move them back, clean the one they came from. Repeat until you get them all. If they got the infestation under control, I have my doubts if a snail would stay and survive in the digestive tract of a fish from now until March, although I think they'd need to be sure of that before stocking them. Time is certainly of the essence, you can't sit on it and hope it gets better. But if there were a bunch of fish exposed in the past, and those fish were moved to a clean raceway temporarily while their raceway was cleaned, moved back, and that raceway remained verifiably clean for months, and a representative gut sample shows no remaining snails, I'd not be against stocking them.

The point is, buy time and work the problem, don't jump to the conclusion that all of these fish have to be killed just yet. But yeah, the priority needs to be on not spreading the snails. If you can do that and save the fish, great!

The only information we have is that they have not been killed "yet" in "hopes" of being able to stock them in the future. That 1 co-op hatchery recieved them, meaning they haven't been used for fall stockings. So I'm somewhat encouraged at the approach, it sounds as if they don't succeed in eradicating them they won't stock them. Giving them to a co-op was a mistake and should be stopped immediately. In addition, that co-op should be investigated to make sure they don't stock their fish until they fix their issues.

 

[silverfox]

If I were in charge, I'd say don't stock those fish this fall. Fall stockings may have to be pulled back a little, but take what you can from uninfested hatcheries. Buys some time.

As for the infested hatcheries. Don't kill the fish yet. There are likely efforts that can be taken to disinfect the hatcheries. Move fish to an empty raceway, clean an affected one. Move them back, clean the one they came from. Repeat until you get them all. If they got the infestation under control, I have my doubts if a snail would stay and survive in the digestive tract of a fish from now until March, although I think they'd need to be sure of that before stocking them. Time is certainly of the essence, you can't sit on it and hope it gets better. But if there were a bunch of fish exposed in the past, and those fish were moved to a clean raceway temporarily while their raceway was cleaned, moved back, and that raceway remained verifiably clean for months, and a representative gut sample shows no remaining snails, I'd not be against stocking them.

The point is, buy time and work the problem, don't jump to the conclusion that all of these fish have to be killed just yet. But yeah, the priority needs to be on not spreading the snails. If you can do that and save the fish, great!

For me, how can you be sure you've got them all? I don't know the R0 (Edit> "A single female snail can produce up to 120 embryos and bear about 70 live, genetically identical offspring every three months") of NZ mud snails, but there's only one sure way to make sure they don't end up in the wild.

Is it worth the risk? I can't believe this is even a question.

 

[pcray1231]

I don't know enough of the science either. But you got 5-6 months before these fish would be stocked, and nothing to say you can't hold them longer if needed.

But you can do water sample DNA tests, for instance, which can tell you if a species is present. Again, I'll say that IF, you have trout in a presumed to be clean raceway for a matter of for example 4+ months, with no evidence of a repeat outbreak, maybe a DNA test which shows NZ mudsnails are not present and haven't been for some time, and you open up a representative sample of fish and examine their digestive tracts with no snails. Then yes, I could see being fairly confident. That's far more than we do for whirling disease, didymo, etc. in hatcheries, no?

I do not know how easily that is achieved and whether it's realistic. Efforts to eradicate them have failed, which is perhaps an ominous sign, not just for these fish but for continued use of these hatcheries on affected waters like the Spring Creek drainage. But the OP did say "in hopes" of still being able to stock them, meaning they aren't sure whether it'll be feasible. And while it is NOT good that a co-op hatchery recieved fish, and should be investigated. I'd also point out that this is after fall stockings have taken place, so if only a co-op hatchery got them, they didn't take those fish for fall stockings, that's a good sign that they're not just going to throw them in every creek... If they believe it's feasible to eradicate them and save the fish, by all means, they got some time to do it and show their work, nobody is saying kill them all this minute.

But yeah, agreed, you have to be pretty dang sure before you stock them anywhere outside of the spring creek drainage. And they should NOT be going to co-op hatcheries. And in addition, if co-op hatcheries have outbreaks, you gotta kinda put the foot down there too, and not let them distribute infected fish.

 

[mtelesha]

Snails are not something we can stop nor rock snot. The bugs are going to be the victims and hatches are going to severely hurt in the long run. We can only delay the inevitable . Here is the current situation in America. https://www.eddmaps.org/midwest/distribution/viewmap.cfm?sub=14543&lat=46.5&long=-90.5&zoom=6

This all started with stocked rainbow trout in Idaho and ship's ballast in the Great Lakes in the 1980s

 

[Fish Sticks]

I think looking to the future and whats reasonable and whats not we have to think about the means by which those snails got in there. We have a hatchery on a known infested creek. Its going to happen again. These snails are the smaller than a grain of sand early on. If a blue heron or another bird of prey is walking or swimming around hunting in spring creek and flies over a raceway and drops one a couple specks we are at square one. Or if a heron eats a smaller trout and craps part of that out with mudsnails while flying or sitting in a tree above a raceway. I mean the raceway is separated by like 50 feet at one point from spring creek? Do we want to risk transmission every year. We all see the risk but if this is going to happen again what the heck is the benefit.

 

[Mike]

If a co-op had mudsnails already and it only stocked streams that had existing mudsnail populations, then that would seem to be a case where a co-op could receive fish from a source that also had mudsnails.

 

[silverfox]

If a co-op had mudsnails already and it only stocked streams that had existing mudsnail populations, then that would seem to be a case where a co-op could receive fish from a source that also had mudsnails.

I was thinking the same thing. As long as potentially contaminated fish only go in already contaminated waters, it's not really compounding the problem.

 

[salmo]

Just another reason to suspend stocking altogether. Yes, I know that is a radical thought and perhaps elitist, but just my opinion.

 

[Fish Sticks]

Just another reason to suspend stocking altogether. Yes, I know that is a radical thought and perhaps elitist, but just my opinion.

Called for update:

I forgot to mention I called and asked for an update and was told they are trying to use some kind of decontamination tank to quarantine fish coming from NZMS tanks. Basically they are trying to salvage the stocked trout. I asked if this would eliminate the risk of spread and they said no but was the best option available to still stock the fish and try to prevent it. I asked if there is a risk of re contamination of PG and benner due to the watersheds containing NZ mud snails. They said they can put different netting on the raceways and some electric current deterrent devices on outflow but yes its very possible this could keep happening.

I asked where these fish with decreased ,but still present, risk of spread were going and I was informed thats a different department and i’m waiting for a call from them but the thought was somewhere “ north” of the hatcheries.

I am personally very concerned about this as the effects of stocking alone are one thing we are currently navigating and seeking reform on in this state trying to catch up to neighboring states, however the risk for PG and Benner does not seem worth the reward and seems downright unjustifiable. Bear in mind the cost issues already existing with the hatchery program and now this. We need stocking reform badly and if something like this is not enough to spur even a fractional reduction in production/stocking overtop of native fish I don’t know what is.

I will be following up to inquire what post stocking surveys if any are to be done to see if infestations are caused by salvaging these harchery fish for stocking. I would think eDNA surveys of watersheds receiving mudsnails should be done to see if contamination occurs and for accountability. These actions create messaging that hatchery fish > prevention of aquatic invasive species spread.

 

[Mike]

See the 11/11/22 issue of Pennsylvania Outdoor News for a complete description of the multiple measures being taken to address this problem. It is quite an informative article.

 

[silverfox]

See the 11/11/22 issue of Pennsylvania Outdoor News for a complete description of the multiple measures being taken to address this problem. It is quite an informative article.

The article does outline all of the measures being taken, but it sure sounds like they're doing everything possible to avoid euthanizing the fish. That's understandable considering the "investment" in those fish, but the environment should be the primary focus.

The way it's written, it sounds like the emphasis is avoiding any disruption to stocking events rather than protecting the environment (just being blunt about it). I think it's a missed opportunity to educate the readers about AIS and, specifically, NZ mud snails. Instead, it reads like it's meant to put anglers' minds at ease about trout stocking continuing as planned.

The entire article is about the infested hatcheries and the possibility of the fish transporting the snails. Then in the section where it mentions how they're spread, it's all about fishermen (waders, boats, boots, etc.) without mentioning that trout stocking could be the culprit or a culprit.

It also really glossed over the snails being found in co-op hatcheries and what the plan is there. It says they told them not to move fish out of their hatchery, but what will they do with those hatcheries and the fish already in their systems? Are those hatcheries on streams that already have NZ mud snail infestations? Are the co-op hatcheries able to implement the same level of monitoring and management as the state-run facilities? If the decision is made to ship fish out in the spring, where are they all going to go? What is the long-term plan for the co-op hatcheries? How did they get into the co-op hatcheries in the first place? Those are the important questions (IMO) that should've been addressed in the PR piece instead of "don't worry, the white trucks will roll in March come hell or high water."

 

[Fish Sticks]

See the 11/11/22 issue of Pennsylvania Outdoor News for a complete description of the multiple measures being taken to address this problem. It is quite an informative article.

I spoke personally with someone and they walked me through the water sourcing stuff, 300 trout digestive tract surveys, electrical current devices to try and discourage movement from downstream into hatchery, tighter netting over raceways, quarantine tanks. But the answer I got straight from PA fish and boat was that everything they were doing was to decrease the risk of transporting mudsnails but that it would by no means eliminate that risk. That was my point. I also would like to know how much cost this is going to add to the already expensive hatchery system. You have to buy more freezers, hydrogeologist consultants, testing in perpetuity, disinfecting non quarantine tanks continually for the time being, post stocking watershed surveying. All this with no guarantee that the NZMS are not transported in the name of stocked hatchery trout.

At what point does the conversation switch from “ some anglers and private for profit hatcheries will be mad at us for stocking reform” to “despite some public sentiment the overwhelming ecological, financial sustainability , and AIS concerns surrounding the hatchery program are going to mandate some meaningful reforms”?