Silver Worms!!!

[Tomcat]

Caught a nice pair of silvers this evening. When I filleted the fish, I discovered that the innards of the hen were infested with clumps of what appeared to be ramen noodle-like worms. It was a big shock and really disgusting.

I was tempted to chuck the whole salmon in the garbage. However, upon closer inspection, only the guts seemed to be affected. The meat looked fine, so I'm confident that it's safe for consumption.

This is the first time that I've encountered a worm problem with any of my catch. How common are internal parasites with the salmon population in Alaska? Should I be concerned about eating fish that are carriers of this type of worm?

 

[Erik in AK]

There was an article in thursday's paper about this. The worm larvae don't enter the flesh until after the fish dies. Freezing for at least 7 days kills them and of course, cooking does.

Also you should contact F&G. They like to keep track of that kind of info.

 

[Fairweather]

More Common Than You Think

More Common Than You Think

I worked on a Power Troller/Gillnetter down in Southeast during the early 80's. When we targeted Silvers, a good day was 100-200 fish. About 10-15% had worms. Not a big deal. Just clean the fish as you normally would. Freezing and/or cooking will kill any worms/worm larva. They don't affect the taste of the fish - just think of them as extra protein!

 

[TBinKodiak]

Worms in the stomache are fairly common and not a problem. The ones you don't want to eat are the ones that have the white cystes in the meat. I seem to get one or two silvers a year with them, always feel bad about chucking them, but F&G says not to eat them.

 

[sayak]

Reds too!

Reds too!

My wife dip netted a red at the mouth of the Kenai that also had a big clump of round worms. I was surprised because i had heard that reds were primarily plankton feeders. We processed it anyway, but I noticed that the flesh was thinner than a healthy red would be. When held up to the light I could see right through the flanks.

 

[Michael Strahan]

Very Common

Very Common

They're Everywhere! I've found these worms in at least three species of salmon (kings, reds and silvers) and also in halibut. They're also in rockfish, ling cod, and all the other ocean fish we like to eat in the north country. Not a big deal at all, and very common. As was mentioned, they will move out of the intestinal tract of the fish into the flesh; it takes a few hours for them to do that. Fillet or gut your fish sooner rather than later to keep that from happening. As was mentioned, humans can become infected with these roundworms; cook your fish properly and it shouldn't be an issue. I hadn't heard that they could be killed by freezing, but it makes sense. What about the cysts and larvae?

Here are some links on it, for your reading enjoyment-

http://www.hc-sc.gc.ca/fn-an/res-rech/analy-meth/microbio/volume5/opflp_02_e.html

This article has photos: http://www.fao.org/docrep/006/y4743e/y4743e0c.htm


And this one is a real treat: http://www.healthatoz.com/healthatoz/Atoz/ency/roundworm_infections.jsp

I found some just today when I was cleaning some sockeye salmon on the lower Kenai River. Went down there for the dipnetting extention.

Regards,

-Mike

 

[Water_Gremlin]

I thought all salmon had worm, some more so than others.

 

[Michael Strahan]

They probably do

They probably do

I thought all salmon had worm, some more so than others.

WG,

They probably do; I've only found them in reds, silvers and kings, because I don't eat the others (chums and pinks). Steelhead probably have 'em too.

-Mike

 

[Sketch]

Worms are in most salmon flesh. Just don't eat it raw. Sushi grade salmon has been frozen long enough AND at a low enough temperature to kill any worms or cysts. Properly handled, there is no danger.

 

[skydiver]

freeze, heat

freeze, heat

The newspaper article was a good one. Seems I remember them saying there were two kinds of worms..one kind that moves from the guts to the flesh after the fish dies, and the other kind that's already in the flesh. Also, as was stated in the previous post, to kill the worms you have to freeze the meat for 7 days. The article stated that your average home freezer will not freeze hard enough to do the trick. Also, it's not just a matter of cooking the fish...it has to be cooked to a certain temperature. The only salmon I've seen that had worms were silvers I caught out of the Naknek River a few years ago. So many cysts in the flesh that I had to toss them.

 

[Nerka]

sockeye worms

sockeye worms

In Upper Cook inlet a number of sockeye systems are infected with the parasite Philonema sp. This parasite discharges eggs into the freshwater rearing environment of sockeye. The eggs are consumed by copepods (small zooplankton) and then eaten by sockeye fry. Therefore, the infection takes place in freshwater. Upon death of an adult fish the worms do try to leave the stomach and body cavity and can be found moving around in high concentrations.

In the Kenai River and Kasilof River system-- studies by ADF&G indicated that 1000 percent of the population was infected. Upon examination the level of infection varied widely but all fish sampled were infected. In contrast, in the Susitna drainage some lakes were totally clean. ADF&G used this in the 1980's to try and separate out northern bound fish from Kenai and Kasilof bound fish. All clean samples were headed north. So if one could figure out a percentage for the Susitna it was a possibility that an estimate of Susitna bound fish could be made. This was before genetics.

The cost of this program was not great but in 1985 ADF&G took a big budget hit because of decreased oil prices. That stopped the research. In 1989 the oil spill provided money to check out the genetic methods and the parasite approach was dropped.

Just thought you might like some history on a fun parasite. They really are neat critters.