Mt Whitney Zone
Posted By: wagga Livestock & pure water - 04/26/10 12:34 AM
There is a wealth of information in this article.

"It may be that 20 to 40 percent of the cattle carry Giardia," Derlet said in a presentation earlier this year, citing other studies.

"Each infected cow can shed enough cysts -- it takes only 10 cysts to get sick -- to infect the entire city of Los Angeles. That's each day. That is an incredible weapon of mass destruction."


Maybe Monty Python got it right. (would have edited it down to the cowtapult - but I don't know how).

"Both Derlet and Goldman envision a solution in their proposed string of five new national parks stretching 6,000 square miles across the high Sierra. They have even named those dreams: Eureka National Park, Lake Tahoe National Park, Mokelumne National Park, John Muir National Park and Golden Trout National Park."

Now that is a terrific idea.
Posted By: Steve C Re: Livestock & pure water - 04/26/10 04:13 AM
From the article:
"Overall, 15,045 sheep and 35,721 cattle grazed on national forests in the Sierra in 2009, the agency said.

Total grazing fees last year came to $168,942
"

Good grief! All that negative impact, and all it brings in is enough to pay for one or two staff positions!

By the way, I suddenly got a case of giardia symptoms at the end of my 4-day PCT hike through the Stanislaus N.F. area last summer. And I drank all the water untreated. HOWEVER... I got the worst attack at the end of day 4 of the hike. And the worst cattle-grazed area of the hike was covered on day 3. (I got a positive ID of the bug two weeks later.)

And I cannot find anywhere that says one can get symptoms that quickly.

This site reports:
"How soon do the symptoms appear? The incubation period is usually 5-15 days, with an average of 7-10 days."

And most other sites report, as does Wikipedia, "Symptoms usually begin 1 to 2 weeks (average 7 days) after an individual becomes infected." Although elsewhere it says a study showed 6-15 days.

The county health person who contacted me in a followup quickly dismissed the situation as caused by the water on the hike. But the numbers don't add up. I am thinking it might have been from the family pets, or maybe from the daycare my daughter was attending. But who knows?
Posted By: RoguePhotonic Re: Livestock & pure water - 04/26/10 05:47 AM
Now you should have known better Steve then to drink unfiltered water from cow roaming area! crazy
Posted By: Steve C Re: Livestock & pure water - 04/26/10 06:13 AM
> Now you should have known better Steve then to drink unfiltered water from cow roaming area!

Well, I've read stuff saying there is doubt that giardia can survive through the winter, and the area had been washed by many feet of snow melting away. And I still doubt I got the giardia from the hike.
Posted By: George Re: Livestock & pure water - 04/27/10 09:29 PM
Steve:

Strangely, I just saw Derlet a little while ago and asked him the incubation period for Giardia. He said 2 to 4 weeks and thought a few days too quick.

I've got a bunch of other articles from Bob Derlet and his colleagues at Sierra Nature Notes:
www.sierranaturenotes.com

There's also a really interesting data set that I keep meaning to publish, which I'll try to put at the top of my list. It was a fairly well done study in Yosemite by a guy named Atwill at UC Davis. Only the data is published, not a paper. Anyway, grad students (undoubtedly!) collected, weighed and took samps of horse manure between Tuolumne Meadows and Glen Aulin. They examined for both giardia and chryptosporidium. They also estimated the number of poops per mile as well as the number of cysts per poop.

Incidence of giardia from sample total over 4 years was (this is from memory) about 3 to 6% of all samples. Crypto was, I think 2 to 3%. Belding ground squirrel droppings were also sampled and found to have something like 60% giardia -- HOWEVER it was not the type that humans are susceptible to. The horse/mule giardia was the type that humans are susceptible to and is thousands of cysts per poop, to say nothing of the increased nitrogen and phosphorous loading of meadows and streams.

George
Posted By: Steve C Re: Livestock & giardia - 04/27/10 10:15 PM
The one thing I'd like to know about Giardia, though, and the other critters as well:

If that manure lies there through a winter, what is the likelihood of finding harmful bacteria and cysts? In other words, is it reasonable to assume the winter snow and runoff and harsh temperatures will neutralize them?
Posted By: George Re: Livestock & giardia - 04/28/10 11:58 PM
Steve:

As far as giardia goes, no, I think the cysts can persist for several years, though not sure of actual time. One full year at least. I'll ask Derlet next time I see him.

g.
Posted By: Steve C Re: Livestock & giardia - 04/29/10 12:30 AM
Thank you George. I understand that about Giardia cysts. But then, since Dr. Derlet is actually out taking samples, I wonder if he's been able to substantiate that in the Sierra.

The reason is that I am wondering how likely it is to get an infection. Only a few cysts surviving is different than most of them remaining viable after a winter. And after so much water has coursed through an area, I am curious how concentrated they would be in the streams I was drinking from.

Please do ask him, and ask if he's done any testing of water draining through those contaminated sites where the livestock had NOT been present since the winter.
Posted By: wagga Re: Livestock & giardia - 04/29/10 02:32 AM
At one end of the western USA population bell curve, the Sierras are a massive pain in the ass. Ask the truckers, railroaders & the Donner party (who invented autojerky).

At the other extreme, we have the members of this & other boards who revel in the wilderness experience.

But for all of us, the greatest significance of the "Range of Light" is that it is a massive watershed. A source of pure water to power the most fertile valley on earth, and on the East side, to allow the pullulating growth of the Southern California Space Station.

Eastern states are buying watershed to protect their water supplies.

So, if we could automagically create a number of new National Parks to protect all the Sierra Nevada lands above the normal snow line, how long would it take before the water becomes pure?.

Also, if Giardia is a native species, would we be obliged to protect it?.
Posted By: wagga Re: Livestock & giardia - 04/29/10 01:59 PM
Letter to the Editor in Today's Bee.
Posted By: + @ti2d Re: Livestock & giardia - 04/29/10 02:37 PM
Originally Posted By: wagga
..if Giardia is a native species, would we be obliged to protect it?...
Good point, wagga. What California needs is an official state microorganism!

Hey, put a giardia on the CA state flag since there ain't no more grizzlies!

Better yet, a cow in lieu of the bear, a giardia in lieu of the star, brown instead of green below the "cow," and "Happy Cow Lives in California Republic."
Posted By: Bee Re: Livestock & pure water - 05/01/10 04:44 AM
Originally Posted By: Steve C
Well, I've read stuff saying there is doubt that giardia can survive through the winter, and the area had been washed by many feet of snow melting away. And I still doubt I got the giardia from the hike.


While looking for info on a similar subject posted on the WPSMB, I ran across this research article:

Quoted from Effects of the Norwegian winter environment on Giardia cysts and Cryptosporidium oocysts

"Shear forces generated during freeze-thaw cycles are postulated to have disintegrated the parasites exposed to the Norwegian winter and retrospective laboratory studies support this theory. Increased dye inclusion, possibly indicative of viability loss, was also noted. The refrigerated control parasites exhibited no decline in numbers, and alteration in dye inclusion characteristics for refrigerated parasites was slower. Cryptosporidium oocysts were apparently more robust than Giardia cysts; differences between isolates were also noted. These results suggest Cryptosporidium oocysts and Giardia cysts do not persist in the Norwegian terrestrial environment over winter, and when detected, will have been excreted since the previous winter. Differences in the morphological characteristics, matrix effects, and the possible relationship of the dye data to parasite survival are discussed in relation to further studies."

http://www.ncbi.nlm.nih.gov/pubmed/14749905

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