New Great Lakes Exotic: Asian Tapeworms

[taxi1]

12/22/08 by Jeff Alexander | Muskegon Chronicle

An outbreak of tapeworms in Lake Huron walleye has Michigan officials
urging people to avoid eating sushi made with freshwater fish caught in
the Great Lakes region.

The warning came as a Canadian researcher reported the first documented
case of Asian fish tapeworms in Great Lakes fish.

David Marcogliese, a research scientist at Environment Canada's research
station in Montreal, reported the discovery of Asian tapeworms in Lake
Huron walleye in the most recent issue of the Journal of Great Lakes
Research.

The foreign tapeworm, the 186th invasive species documented in the Great
Lakes, likely was imported to the region with infected bait fish,
Marcogliese said in the article.

"This parasite is known to cause weight loss, anemia and mortality in
young fishes," Marcogliese said.

Numerous anglers began reporting finding tapeworms in walleye caught in
Lake Huron and Saginaw Bay, according to a Michigan Department of
Natural Resources memo. Fish from some inland Michigan lakes also were
infected with tapeworms, according to the DNR memo.

Some species of tapeworms are native to the Great Lakes fish. The
discovery and proliferation of Asian fish tapeworms is a recent
phenomenon that could harm walleye and other fish species, according to
DNR officials and Marcogliese's research.

Researchers indicated the Asian fish tapeworm, one of the world's most
pernicious invaders, will likely spread across the Great Lakes region.
The tapeworm can grow to one-foot-long in large fish, such as carp,
Marcogliese said.

DNR officials said it is safe to eat fish that have tapeworms, provided
the fish are thoroughly cooked, smoked or pickled using normal food
preparation techniques.

"We do not recommend making sushi from any species of freshwater fish as
the risk to humans is not known," according to the DNR memo. "It is a
very bad idea to eat any freshwater fish raw or poorly cooked as fish
parasites use fish-eating mammals and birds as hosts and it is not known
if humans can also be hosts."

Tapeworms are ubiquitous in waters where fish live, but the incidence of
the parasites infecting fish has surged in the past two years, according
to DNR officials. State officials said the problem may be due to changes
at the base of the Great Lakes food chain caused by zebra and quagga
mussels, two other invasive species.

Asian fish tapeworms were carried into the U.S. in the 1960s by federal
officials who imported Asian carp to control algae in Arkansas fish
ponds. The invader has since spread to lakes and rivers across much of
North America, according to federal records.

The invasive tapeworms enter the fish food chain when zooplankton ingest
the creatures and become hosts for the parasite. The tapeworms move up
the food chain as zooplankton are eaten by small fish; the pests mature
and produce eggs once in the intestinal tracts of walleye and other fish
species.

Fish excrete tapeworm eggs in their feces. The eggs settle on lake
bottoms, where zooplankton eat them and give rise to a new generation of
the pests.

The mere sight of tapeworms can tarnish a fishing trip -- the creatures
are known to slither out of the mouths and gills of dead fish.

To avoid finding a tapeworm in your fish cooler, DNR officials recommend
gutting fish immediately after catching them and disposing of the
entrails after returning to land. It is illegal to discard fish guts in
Michigan waters.

[Melbs7]

Sweet!! Another invasive species introduced by a government agency!!! Gotta Love it!!!

[blufloyd]

The native fish tapeworm Diphyllo something is way more scary, think 30 feet.

[taxi1]

Sweet!! Another invasive species introduced by a government agency!!! Gotta Love it!!!

What's even sweeter is the feds who bring all this crap in or are incompetent are supposed to protect us from this stuff. 

[jkw]

dang that sucks you guys......im sorry to hear it.....i dont think we have any tapeworms or any parasites here except for some kind of mussell that is pretty much controlled in the kenai river mouth.  the government is just a bunch of screw ups anyway....just on a higher scale...we are worried here in alaska about pike infesting our salmon streams and lakes.....small worries i guess compared to you guys.....northern pike are not native to southcentral alaska.....so if they get a good foothold in a salmon system they WIPE it out, and quick......Alexander Lake and creek used to be one of the best places to catch king salmon and silver salmon, and used to have awesome rainbow trout fishing, but now theres hardly anything left but pike......in the lake they is nothing but big 24" and up, and they pretty much just eat each other there.....

[Adam Bomb]

These have been around in numbers on Saginaw Bay for at least the last 3 years. Its funny how when you fish out there youll hit a pod of fish that has them. Other days you catch just as many and none are infected....Hard to believe we keep getting all these invasives. Somethings gotta change.

[taxi1]

Right now APHIS (the feds) are making us fish farmers test for the VHS virus on our fish farms rather than do anything about the way these exotics are getting into our Great Lakes and beyond. Never mind the virus has not been found on any fish farms and probably won't. Then they want to take it a step farther and want fish farmers with open water sources to test monthly. That makes the health testing costs for one trout farmer I know in Michigan to jump to $60,000 annually which I doubt he even makes a year. So obviously that would put him out of business. And he's not alone.

I used to be so naive. I thought the government actually knew what it was doing and those PHD's actually meant something. I was so wrong.

[Lobes]

So what's next? Do you suppose they'll try to tell us there might be a good reason we shouldn't eat raw fish guts?   

                                             
NBG

[taxi1]

So what's next? Do you suppose they'll try to tell us there might be a good reason we shouldn't eat raw fish guts?   

                                             
NBG

What's next? Another exotic of course. We are now up to 186 on exotics in the Great lakes. It's anyone's guess what comes next. Another pathogen? Another shellfish? Another fish species? Considering the bighead carp is right on the verge of Lake Michigan and one government agency is fighting to keep voltage down on the weir it's just a matter of time before Lake Michigan and Lake Huron are packed with these things. It's thought they could devastate the food chain in those lakes. One individual tells me when water levels are high they can go around the weir anyway. Not sure if that's the case but if it is...

Lower-voltage carp barrier gets Coast Guard's blessing
<http://www.jsonline.com/news/wisconsin/36280069.html>
 
Less than a week after a group of 29 U.S. senators and representatives
wrote a letter demanding answers as to why an electric Asian carp
barrier built in 2006 to keep the monstrous fish from invading the Great
Lakes had not been turned on, the Coast Guard has given it the green light.

But the agency wants the barrier to operate at only one volt per inch,
or one-quarter its capacity, which biologists say is not strong enough
to repel all sizes of fish.

If push comes to shove

Jones said if the Corps decided to operate the barrier against the Coast
Guard's wishes, the only recourse the Coast Guard would have is to shut
the waterway to navigation. He said that is unlikely, but his boss said
earlier this fall it is a possibility if it's determined that
dangerously high voltages are needed at some points of the year to repel
juvenile fish.

http://www.jsonline.com/news/wisconsin/36280069.html

[taxi1]

These have been around in numbers on Saginaw Bay for at least the last 3 years. Its funny how when you fish out there youll hit a pod of fish that has them. Other days you catch just as many and none are infected....Hard to believe we keep getting all these invasives. Somethings gotta change.

Are you sure they are the same species? There are several species of tapeworms.

[Adam Bomb]

Hard to say. From what i understand unless your a parasitologist its difficult to distinguish between the different tapeworms. All i know is theres been tape worms showing up in numbers on the bay for the past 3 years solid. From what ive just read, In 2007 the abundant complaints from anglers about tapeworms finally warranted a look at things from biologists. All of the samples taken were of fish with native tape worms.

But, heres where my logic comes in. For parasitologists to come acrossed walleyes with the Asian strand it would make it seem that they must be in our walleyes in some kind of numbers. Otherwise they would be pretty lucky to have found it if it were an isolated occurance...Ecspeciall y on a body of water as vast as Lake Huron...At least IMV. So, although it didnt show up in their samples, i personally think it may have been there already...maybe not in strong numbers, but a contributing factor.

I can say this, on several occasions over the last three seasons we've brought fish through the ice or in the boat that have had tapeworms hanging out their anus. Some are fairly long. Long, thin/flat, white segmented wriggling tapeworms.

Heres an article from the DNR page on tapeworms.
http://www.michigan.gov/documents/dnr/tapeworm-walleye_231757_7.pdf

[taxi1]

Heres an article from the DNR page on tapeworms.
http://www.michigan.gov/documents/dnr/tapeworm-walleye_231757_7.pdf

Good article but it must be noted how your DNR neglects to mention overstocking of salmonids may have also been a factor in the reduction of alewife populations. 

[Adam Bomb]

Theres no question about it...You wont get an argument here. Salmon get big in 4 years. To accomplish that they put the feed bag on big time.

[taxi1]

Theres no question about it...You wont get an argument here. Salmon get big in 4 years. To accomplish that they put the feed bag on big time.

True, but when the data said the states on the Great Lakes needed to reduce their stocking rates some bowed to angler and political pressure to keep up the present rates.

[Adam Bomb]

I would agree with that as well. The salmon fishery is very popular with anglers and businesses alike on the Great Lakes. Those fish draw allot of attention from folks within/out of state to the towns that dot the shoreline where salmon are/were prevelent. Anglers really enjoy catching salmon and while theyre there they spend allot of money at local businesses stimulationg the local economy. So, its not really a surprise that there was heavy pressure to keep the stocking rates high...Right or wrong, thats politics for ya.

[taxi1]

I would agree with that as well. The salmon fishery is very popular with anglers and businesses alike on the Great Lakes. Those fish draw allot of attention from folks within/out of state to the towns that dot the shoreline where salmon are/were prevelent. Anglers really enjoy catching salmon and while theyre there they spend allot of money at local businesses stimulationg the local economy. So, its not really a surprise that there was heavy pressure to keep the stocking rates high...Right or wrong, thats politics for ya.

Absolutely!