Snakehead Impact Study

afishinado

afishinado

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Attached is an article about the negative impact in existing species believed to be caused by the snakehead introduction into the Chesapeake Bay watershed.

https://chesapeakebaymagazine.com/study-fish-populations-drop-since-snakehead-invasion/?fbclid=IwAR0HYM7zQuzIGPK1x9xwuerWLQwUZm4PbxzyR1yqjitcMXyOj-VkBle7GKE
 
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poopdeck

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There is an erie silence from the snakeheads don't eat children crowd. Probably looking for snakehead fishermen videos To discount what the experts say.

Thanks for posting.
 
jifigz

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It is what it is at this point. There is no getting rid of them and they will spread to where they can/habitat that is suitable. Let's just hope anglers don't keep dumping them everywhere and taking that liberty into their own hands.
 
Fredrick

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poopdeck wrote:
There is an erie silence from the snakeheads don't eat children crowd. Probably looking for snakehead fishermen videos To discount what the experts say.

Thanks for posting.

Sorry to disappoint pooppy , but if this study was from someone other than Mr. Love I’d consider it valid . Snakeheads are his white whale , anything from him is like watching the Democratic Party (love)
trying to impeach the president (snakeheads) .. So needless to say his studies are going to be far from bias. I have friends down there’ saying there is a problem and I also have friends that are saying there isn’t , everything is fine . In the meantime I plan on fishing down there allot more this summer . Also I made up this meme a while ago after hearing Joe Love”s hatred talk for snakeheads at the symposium. Enjoy
 

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afishinado

afishinado

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Fredrick wrote:
poopdeck wrote:
There is an erie silence from the snakeheads don't eat children crowd. Probably looking for snakehead fishermen videos To discount what the experts say.

Thanks for posting.

Sorry to disappoint pooppy , but if this study was from someone other than Mr. Love I’d consider it valid . Snakeheads are his white whale , anything from him is like watching the Democratic Party (love)
trying to impeach the president (snakeheads) .. So needless to say his studies are going to be far from bias. I have friends down there’ saying there is a problem and I also have friends that are saying there isn’t , everything is fine . In the meantime I plan on fishing down there allot more this summer . Also I made up this meme a while ago after hearing Joe Love”s hatred talk for snakeheads at the symposium. Enjoy

The study is by the US Fish & Wildlife Service and the MD DNR >

https://www.fws.gov/northeast/marylandfisheries/pdf/FINAL_Blackwater-Fish-Community-Comparison.pdf?fbclid=IwAR2327gF4PYIcAklJ7NQXS12PSORpghivg9ip7nN73jgGwmQyU5FtdsYF9c

I actually hope every is fine, but I consider this info from the study more reliable than info from your fishing buddies; but your choice on what you believe is up to you.
 
Fredrick

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Tom Joe love spearheaded it the us fish and wildlife just paid most of the bill . And my fishing buddies are on the water down there allot more . Than both of them . Just my two cents and MDDNR is notorious for mismanaging their fisheries . There maybe a problem maybe not ether way I’m still going to fish for them .
 
marcq

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I’ve seen them in the schuylkill bellow fairmount things are nearly impossible to catch in that river most guys snag them but at night you see them smashing fish on the top. It’s like someone throwing bricks into the water. I’m still catching plenty of stripers and walleye there so I can’t say they are hurting the river.
 
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Mike

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The concern is not just for fish species that anglers typically catch with hook and line. The entire food web is important. For example, would typical anglers notice if American eels were missing from the food web? I doubt it. If American eels go missing, so then do certain mussel species which depend on the eels to transport young mussels upstream, where they then drop off and take up residence in river/stream gravel and rubble. They are nature’s water filters. Because they can exist in such high numbers in river and stream systems, they can readily enhance water quality. Without them?...not so much.

Why the reference to eels? Because it is apparent that snakeheads heavily feed on eels and before snakeheads arrived eel populations were already reduced in many locales.
 
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poopdeck

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how can anybody argue with Fred's buddies. At least you are enjoying catching them. Any chance you and your buddies will start eating them?
 
afishinado

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Mike wrote:
The concern is not just for fish species that anglers typically catch with hook and line. The entire food web is important. For example, would typical anglers notice if American eels were missing from the food web? I doubt it. If American eels go missing, so then do certain mussel species which depend on the eels to transport young mussels upstream, where they then drop off and take up residence in river/stream gravel and rubble. They are nature’s water filters. Because they can exist in such high numbers in river and stream systems, they can readily enhance water quality. Without them?...not so much.

Why the reference to eels? Because it is apparent that snakeheads heavily feed on eels and before snakeheads arrived eel populations were already reduced in many locales.

Like Mike points out, the introduction of invasive species may have far reaching consequences in future, which are not readily apparent to us right now.

Anyway, what's done is done, it can't be reversed. But hopefully the genius bucket biologists that have spread them to other waterways will stop doing so, and the ecosystems where they are right now will be unaffected in the future.
 
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SteveG

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I'm not a proponent of snakeheads, but I don't understand why a similar stance is not taken on flathead catfish in the Susquehanna. While a "kill statute", such as in effect for lake and brook trout in certain areas out West, may not completely fix the problem. Would it not potentially help? I can't imagine how much food is required to maintain the large catfish I see pics of.
 
Dave_W

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SteveG wrote:
I'm not a proponent of snakeheads, but I don't understand why a similar stance is not taken on flathead catfish in the Susquehanna. While a "kill statute", such as in effect for lake and brook trout in certain areas out West, may not completely fix the problem. Would it not potentially help? I can't imagine how much food is required to maintain the large catfish I see pics of.

This is a good point.

I think it is illustrative of the competing points of view that arise when a problematic new fish is introduced to a watershed when that fish is embraced rapidly by anglers. I'm inclined to agree that flatheads have had (or may have) more impact on the biodiversity of the Susky than SH have had on the Bay region. Yet the PFBC has to concede the popularity of FH in the Susky.
Hhmm...
 
jifigz

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This is just purely my opinion, but I feel that there are "degrees of invasiveness." Flatheads are native to North America (and Pennsylvania, for that matter) and people here are familiar with catfish and this country has a long tradition of angling for catfish, primarily in the south. Northern Snakeheads are from China, Korea, parts of Russia, etc and are totally unfamiliar with this exotic species. I think that plays an important role in how people view these species.

I agree that flatheads are a bigger problem but then again who knows. I bet flatties and blues would have no problem chowing down on some snakeheads.
 
Fredrick

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Mike wrote:
The concern is not just for fish species that anglers typically catch with hook and line. The entire food web is important. For example, would typical anglers notice if American eels were missing from the food web? I doubt it. If American eels go missing, so then do certain mussel species which depend on the eels to transport young mussels upstream, where they then drop off and take up residence in river/stream gravel and rubble. They are nature’s water filters. Because they can exist in such high numbers in river and stream systems, they can readily enhance water quality. Without them?...not so much.

Why the reference to eels? Because it is apparent that snakeheads heavily feed on eels and before snakeheads arrived eel populations were already reduced in many locales.


Mike, every study I have read never mentioned that eels were a favorite prey item for snakeheads.There is two studies that I am aware of, I could only find the one from love. Its a controlled study and love introduced several prey and the study shows they are not selective feeders and mostly eat what is in abundance . If the state is worried about the eel populations why are they letting tackle shops sell them as bait ?

Read attached study There was no evidence of strong prey preferences for northern snakehead. The low levels
of electivity during mesocosm experiments demonstrated that common prey items are most
frequently consumed (Fig. 2

https://dnr.maryland.gov/fisheries/Documents/Snakehead_Impacts_10-01-2019.pdf

Unfortunately, I cant get access to the one feeding study that I have saved at home but here is a portion of it

http://cwf-fcf.org/en/resources/research-papers/Lapointe-et-al-

2019-Diel-activity-of-Northern-Snakehead.pdf
Two hundred seventy-three Northern Snakehead (average total length = 600 mm, SD = 125; average weight = 2452 g, SD = 1369) were captured, 55% of which had items in their gut, and 21% of which had fresh items in their gut (digestion level 1). At least 5 fish were captured during each 1-h period of the 24-h cycle. Northern Snakehead primarily consumed fish (97%), with Bluegill Lepomis macrochirus and Banded Killifish Fundulus diaphanus being the most common by weight and number, respectively (further details available in Saylor et al. 2012). The amount of variation in feeding activity explained by RF analysis was low (6.5%). Fish length was the most important variable in predicting feeding activity, with smaller fish (
 
afishinado

afishinado

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Fredrick wrote:
Mike, every study I have read never mentioned that eels were a favorite prey item for snakeheads.There is two studies that I am aware of, I could only find the one from love.


Details from a recent article and study that supports the info in Mike's post, above by Drexel University and an "extensive" survey in FDR Park along with additional info concerning the Delaware river. >

They are voracious predators capable of disrupting ecosystems and threatening desirable species wherever they’re introduced. Academy scientists and resource managers are concerned that the species may negatively affect the Delaware River by preying on other fishes and disrupting food webs. They pose a serious threat to endangered species. Because they are an invasive species, the adults have no natural predators where introduced. However, they may be vulnerable to other fishes, particularly when young.

In the Potomac River, snakeheads feed predominantly on fish, particularly killifishes and sunfishes. In the Delaware River, there is great concern that they may be feeding on, and therefore directly impacting, native and recreational species such as American eel, striped bass, American shad and other popular fishes.

How do we know this?
Academy scientists have extensively surveyed the fish assemblage in the FDR park system using electrofishing. We have found sunfishes, American eel, a turtle, and other items in the stomachs of the northern snakehead that we’ve taken from FDR Park. The northern snakehead also has been known to eat white perch, largemouth bass, frogs, crustaceans, small birds, mammals and reptiles.

The best thing people can do is learn to identify the fish and where it is known to occur. If they catch one, they should not release it. They should kill it and report it to the appropriate agency (e.g., Pennsylvania Fish and Boat Commission or New Jersey Fish and Wildlife). It’s illegal to possess live snakeheads in many states.


Link to source > https://www.anspblog.org/reeling-in-frankenfish/
 
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Mike

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When the 6-8 inch yellow phase American eels are migrating in spring, the snakeheads can be full of them and nothing else.
 
afishinado

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Another recent article about snakeheads >

https://lancasteronline.com/sports/outdoors/ugly-frankenfish-is-spreading-threatening-pennsylvania-game-fish/article_f7c6789c-2674-11ea-9736-93b090e24de8.html?fbclid=IwAR3t0iRbzj1bMeiKyVf_LKT5FbdtHF7P7idqyuo1bsr-QEWQX74rplVGBWU
 
jifigz

jifigz

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Mike wrote:
When the 6-8 inch yellow phase American eels are migrating in spring, the snakeheads can be full of them and nothing else.

That is really unfortunate. Basically every predatory fish does prefer to eat soft rayed fishes so eels fit that category.

This is just like politics. Either side doesn't want to hear the other side's story and whatever view one side holds the other finds blasphemous. We will just have to wait and see the damage and hope knuckleheads quit transporting them.
 
Fredrick

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Mike wrote:
When the 6-8 inch yellow phase American eels are migrating in spring, the snakeheads can be full of them and nothing else.

If the state is worried about the eel populations why are they letting tackle shops sell them as bait ?

Anyone that fishes for snakeheads knows that they are not ravenous eaters that just gorge themselves on prey all day . If that was the case I would be having 30 fish days. The fact is that they only eat when they are hungry and have a slow metabolism. Another fact is they are notorious for having lock jaw. And I'm sure that any gamefish that inhabits the same areas would have a full stomach of eels or any other prey item that is migrating at the time.


Snakehead is just a FISH and they eat the same prey items as any other non native gamefish in their area .
 
jifigz

jifigz

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Fred, no one has said anything contradictory to what you said. The articles need to be taken with a grain of salt because it is journalism and that is naturally hyperbolic sensationalism.

What you can't deny is the down sizing of certain fish populations. If it says bullheads are down such a percent in population and it occured after snakeheads then studies/science need to find whether it was snakeheads or other factors or a combination that contributed.
 
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