Snail Die Off in Lake Davis

[Tracy Chimenti]

I hope they recover. They eat alto of them in the fall and winter.

let's just hope they don't bunch of slimy, brood-stock snails.

[1flyfisher]

Well I have not received a response from CADFG regarding the letter I sent to them inquiring as to why the snails have died off in davis lake so I called today. Of course I never got through and was only able to get to Amber Rossi's voice mail. So, I left a message for her to either call me back or email me back,,,,I am still waiting to hear back and see if they have looked into it and if they have any answers.

[michaeln]

Thanks for the update. I'm not surprised they have not responded though.

[1flyfisher]

Neither am I.

Thanks for the update. I'm not surprised they have not responded though.

[ycflyfisher]

1,

I'm actually quite shocked you haven't gotten a response to this one. I've never posed a question to a DFG staffer that didn't get a response in a reasonable amount of time. Even if the response was time consuming to craft or if the staffer in question was not able to either answer my question or thought my concern was "off base". I've always gotten a response of some kind. Your original message is definitely one deserving of some kind of response IMO. I'd suggest contacting another staffer in the same office in the event that Amber may be out for a prolonged period of time and simply forgot or didn't have the chance to update her email autoresponse or voicemail.

[1flyfisher]

I emailed her on July 21 and I called yesterday Aug17 and re-sent the original email again yesterday to the email address listed. So I will give them a week or so then I may try calling the local dfg office in portola if I can find another contact there. The ph # I have is just to A Rossi's vm. so I will have to find another ph number. If anyone knows the office ph# or another contact there or another email I can send my letter to please post it. I'd like to speak to someone that is involved with Davis and not a sac office person.

1,

I'm actually quite shocked you haven't gotten a response to this one. I've never posed a question to a DFG staffer that didn't get a response in a reasonable amount of time. Even if the response was time consuming to craft or if the staffer in question was not able to either answer my question or thought my concern was "off base". I've always gotten a response of some kind. Your original message is definitely one deserving of some kind of response IMO. I'd suggest contacting another staffer in the same office in the event that Amber may be out for a prolonged period of time and simply forgot or didn't have the chance to update her email autoresponse or voicemail.

[1flyfisher]

On Thursday, August 26th, 2010 my co-worker and I sampled three
separate portions of Lake Davis via D-ring dip net and boat
electrofishing. The dip net samples and the rainbow trout stomach
contents verified that there are four families of snail (Lymnaeidae,
Planorbidae, Physidae, and Valvatidae) currently residing in the lake.
More than likely, the snail populations are fluctuating as the lake get
back into its normal cycles. I was able to find a paper which
demonstrated the results of the first chemical treatment of Lake Davis
in 1997. I have attached a link to the paper in this email. Basically,
the paper shows a decline in snail population immediately after the 1997
lake treatment, followed by a rise in snail population as the years
progressed post treatment.

http://www.dfg.ca.gov/lakedavis/docs...cInvertRpt.pdf

[1flyfisher]

As for the fish parasites, we are aware of the situation at Lake Davis.
We examined a number of trout from Lake Davis last year to confirm the
identity the organisms being seen. We found light to heavy numbers of
copepods on the fish. The majority of the fish lice we observed were of
the genus Salmincola. There may be a few of the genus Lernaea as well.
Common names for these copepods are “anchor worm, fish maggot” etc.
The organisms found on these particular fish are commonly found in
waters throughout the western United States. This organism usually does
not affect fish health, though its appearance on fish can be
unattractive.
The presence of this organism on fish does not render the fish unfit
for human consumption. It is not an internal parasite, but rather
infects the gills, fins and flanks of susceptible species of fish. There
are no practical treatment options available for lakes and reservoirs.

The increased numbers of these organisms being seen this year is most
likely due to the warming of the water and the high number of fish
planted into Lake Davis. The organisms were already in Lake Davis.
When Fish and Game planted the large number of trout into the lake we
provided a large number of hosts for the parasite to live on and
multiply from. The copepod numbers will decline with cooling water
temperatures and decreasing fish numbers.

Please feel free to contact me if you have any other questions.

Sincerely,

Amber


Amber S. Rossi
District Fisheries Biologist: Plumas/Sierra County
California Department of Fish and Game
P.O. Box 419
Quincy, CA 95971
Phone (530) 283-6864
Cell (530) 520-4753
Fax (530) 283-2938
arossi@dfg.ca.gov

[michaeln]

The copepod letter is the same one they sent me and also to a guy on another board. It's a form letter, whether it be on paper or email. They aren't looking into it and are hoping it will go away.

[Darian]

I'm curious about why we should expect a personalized response to a number of inquiries about the same subject

Seems to me that the info in the note addresses the questions that have been raised by posters on this BB. Snails are still in the lake but maybe in a down cycle and Copepods were already in the lake and will probably die off during periods of cold water.... Since there doesn't seem to be anything else look in too, they probably won't spend much time on it. But, I'm sure they don't hope that "....it...." will just go away.

IMHO, the DFG response seems adequate for the questions asked whether in a form letter or not. If their response doesn't satisfy, ask a new question(s)....