NZ Mud Snails

[tcorfey]

This past year while I was fishing the Stanislaus River and after I was finished struck up a conversation with some other anglers and they started talking about going to another river. I asked them if they knew that they needed to treat their wading equipment due to the Mud Snails and they responded that they were unaware that the Stanislaus had them. They thanked me for letting them know. I did some further research and found this reference, thought it would be a good for everyone.

(PS I keep this on my phone as a note to reference before I fish)

Infected areas:

- Eastern Sierras
Hot Creek
Owens River
Rush Creek
Lone Pine Creek

- Western Sierras
Calaveras River
Stanislaus River
Mokelumne River
Lower American River
Shasta Lake

- Valley
Putah Creek
Napa River
Piru Creek
Alameda Creek
Hayward Creek
San Lorenzo River
Antioch Creek
Baxter Creek

Major Rivers
Truckee River
Russian River
Klamath River
Smith River
(Since they are in Shasta Lake and Lower American and Putah I would assume
The lower Sacramento River also has them but it is not listed.)

Humboldt
Big Lagoon
Lake Earl
Lake Talawa


Info from:
http://www.flyline.com/environmental/nzms/

Pdf on controlling:
https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=3867
Or Google
controlling the spread of new zealand mud snails on wading gear

[Fly Guy Dave]

Thanks for the detailed info, very useful!

And on a related topic...

This does bring up another question that I am curious about. Since it has been several years since the accidental introduction of these snails to these waters, does anyone out there have any information or data on how the NZ mud snail has affected these fisheries? I recall some pretty draconian predictions about how these snails were going to overwhelm all of the lower aquatic life, thereby snuffing out any organisms higher up on the food chain (like trout), but I've fished some of these waters for quite a long time and I haven't seen any drastic changes from how they were before and how they are now.

I believe I've asked this question in the past, but I don't recall any definitive information either pro or con. I assume that DFW or USFW would have an ongoing study, but I haven't heard anything new about the NZ mud snail for a long, long time. If anyone has some insight on the NZ mud snail issue, I would greatly appreciate it.

Thanks!

[Bob Loblaw]

Full disclosure - I'm practicing marine biology here without a license.

My understanding of these pesky critters is that once they are introduced into a system they have a huge population explosion for a couple of years and can really mess up a fishery, but after that their numbers decline to a manageable level and they don't pose a serious threat to a river....they compete for food and we'd all rather they were not there, but they don't pose a huge risk to the ecosystem once their numbers stabilize.

[JAnderson]

Besides the lower Stan they are also on the lower Merced River as well fyi...