There was an interesting story in the Las Vegas Journal Review on August 20th. which had a passage and quote from California Senator Diane Feinstein (emphasis mine):
Both U.S. Sen. Dianne Feinstein, D-Calif., and Ensign announced that they and other members of their delegations will reintroduce a bill in Congress to provide $390 million for additional preservation projects at Lake Tahoe.
Ensign said some have called the summits “publicity gimmicks,” but they are an important way to focus at what still needs to be done.
He said he has noticed how the dense forest around the Nevada side of the lake has been thinned dramatically in an effort to prevent forest fires. Feinstein praised Nevada for its efforts to stop fires, adding she wishes she saw the same results in California.
Unlike other officials, Feinstein blamed global warming for the degradation of Lake Tahoe.
“The real culprit in my mind is global warming,” she said.
Since 1970, the water temperature of the lake has risen by about three degrees, according to scientists.
I have no dispute about the temperature rise, but I do have a dispute with her assignment of blame, especially since she is my senate representative. I’ve found something interesting that leads me to think that global warming and Lake Tahoe’s water temperature are not significantly connected.
First about her statement. Perhaps Senator Feinstein is recalling this article on Lake Tahoe from 2004 in the San Francisco Chronicle.
There was a weak caveat in that article that Feinstein likely ignored if she read it:
No one can be certain if any given change is due to human activity, but the widely held assumption is that emissions of carbon dioxide and other heat-trapping greenhouse gases are involved.
I’d like to add a reason of my own for Senator Feinstein and the Chron: turbidity.
For those who don’t know, water turbidity is defined by the EPA as:
Turbidity is a principal physical characteristic of water and is an expression of the optical property that causes light to be scattered and absorbed by particles and molecules rather than transmitted in straight lines through a water sample. It is caused by suspended matter or impurities that interfere with the clarity of the water. These impurities may include clay, silt, finely divided inorganic and organic matter, soluble colored organic compounds, and plankton and other microscopic organisms.
The EPA definition comes from the publication American Society for Testing and Materials, ASTM (2000) D1899-00 Standard test method for turbidity of water. Annual Book of ASTM Standards, Vol. 11.01.
Water clarity and turbidity has been a big issue with Lake Tahoe for many years, and there have been campaigns to reduce the amount of runoff into Lake Tahoe that is a direct consequence of the building boom that has occurred around the Lake in the last century. “Keep Tahoe Blue” is one of those and you’ll see these bumper stickers all over California:
Senator Feinstein is certainly aware of this effort to reduce turbidity and maintain clarity in Lake Tahoe, in fact she is one of the champions of the cause. She drafted the Lake Tahoe Restoration Act in 1999
Her own website has quite a section on it:
http://feinstein.senate.gov/tahoe_restoration_act.html
In that web page is this passage and graph related to it:
Sediment and algae-causing phosphorus and nitrogen, all of which contaminate the water in the lake, continue to flow into Lake Tahoe from a variety of sources. Destruction of wetlands, wet meadows and stream habitat has compromised Lake Tahoe’s ability to cleanse itself of pollutants.
There’s not one word on Feinstein’s Lake Tahoe Restoration Act web page about global warming or climate change. Zilch, nada, zero. I’ll also point out that it looks like the page has not been updated in quite some time. Perhaps after passing the act in 1999 her interest waned.
The graph above can also be found in a different form from the 2009 State of the Lake Report from the UC Davis Tahoe Environmental Research Center (TERC):
TERC writes about the clarity as defined by the Secchi depth measurement:
Secchi depth (the point below the lake surface at which a 10-inch white disk disappears from view) is the longest continuous measurement of Lake Tahoe clarity. The annual Secchi depth is the average of 20 to 25 readings made throughout the year. While lake clarity has improved for brief periods since 1968, the overall long-term trend has shown a significant decline. In the last eight years, Secchi depth measurements have been better than predicted by the long-term linear trend. Statistical analysis suggests that the decline in Lake Tahoe’s clarity has slowed, and is now better represented by the curve below than a straight line. In 2008, the Secchi depth was 69.6 feet and virtually the same as 2007. With the exception of 2005 and 2006, precipitation has been low during the past 8 years. The response of the Secchi depth to a series of normal and above normal years will be very instructive.
What is interesting is that the top two values of the TERC graph occurred in 1997 and 1998, the years of the super El Nino and massive amounts of rainfall (and runoff) in California. I wasn’t surprised to see those years as the peak of low clarity of the last 40, but I was surprised that TERC does not mention it in the report. Perhaps it is counter to the TERC mission to blame nature for peak values.
So we’ve established two things:
1) The water temperature of Lake Tahoe has been increasing. From the LVJR news article:
Since 1970, the water temperature of the lake has risen by about three degrees, according to scientists.
2) As measured by TERC, the turbidity of Lake Tahoe has been increasing, thus reducing the clarity.
While lake clarity has improved for brief periods since 1968, the overall long-term trend has shown a significant decline.
I should add, I think it is a good thing to reduce the runoff issues that contribute to the reduced clarity of Lake Tahoe. This is a clear case where human activities have made a measurable impact on an ecosystem. That said, I believe that same human impact affects the lake temperature. As Dr. Roger Pielke Senior argues, land use and land cover changes have significant local and regional impacts. Lake Tahoe’s clarity decline has been established to be a result of increased runoff and pollutants resulting from the local population increase around Lake Tahoe in the last century.
This USGS publication, Stream and Ground-Water Monitoring Program, Lake Tahoe Basin, Nevada and California, defines the issue:
Lake Tahoe has long been admired for its alpine setting and the clarity of its water. During the last half-century, however, human activity in the lake basin has increased while the lake has been losing water clarity at a rate of about 1 foot (ft) per year.
Now, for a look at what I believe to be a significant contributor to the water temperature increase in Lake Tahoe.
One thing nobody seems to be talking about is the relationship between water turbidity and temperature. It is a quite simple physical mechanism, and quite well established.
For example, here is a peer reviewed study, published in International Journal of Biometeorology on mosquito larvae and increased turbidity contributing to increased water temperature.
The effect of water turbidity on the near-surface water temperature of larval habitats of the malaria mosquito Anopheles gambiae
K. P. Paaijmans &W. Takken & A. K. Githeko & A. F. G. Jacobs (full PDF here)
In that study they write in the abstract:
Water turbidity affects water temperature, as suspended particles in a water column absorb and scatter sunlight and hence determine the extinction of solar radiation. To get a better understanding of the relationship between water turbidity and water temperature, a series of semi-natural larval habitats (diameter 0.32 m, water depth 0.16 m) with increasing water turbidity was created. Here we show that at midday (1300 hours) the upper water layer (thickness of 10 mm) of the water pool with the highest turbidity was on average 2.8°C warmer than the same layer of the clearest water pool. Suspended soil particles increase the water temperature and furthermore change the temperature dynamics of small water collections during daytime, exposing malaria mosquito larvae, which live in the top water layer, longer to higher temperatures.
That is a small scale experiment in shallow water. On a larger scale there are lots of other scientific references available that demonstrate a relationship between increased water turbidity and increased water temperature. Here’s one published in BAMS from the Naval Research Lab looking at turbidity in the Black Sea and water temperature relationships. (Kara et al 2005, PDF here)
The K.P. Paaijmans et al study above writes about the Kara et al 2005 Black Sea Study:
In larger water systems, turbidity is known to change the water temperature. In seas, for example, a high turbidity changes the sea surface temperature (SST), and model simulations of the SST should include turbidity to account for variations in solar radiation extinction (Kara et al. 2004). Kara et al. (2005) demonstrated that using a clear-water constant attenuation depth assumption as opposed to turbid water type to model the SST of the Black Sea, resulted in monthly SST biases as large as 3°C in the summer period.
What I find amazing is that Senator Feinstein, who championed a bill to save Lake Tahoe from reduced clarity, apparently has no idea of the relationship between water clarity and water temperature. Apparently TERC doesn’t see it either, and prefers to blame increased water temperatures on climate change.
Of course, if we take the “global warming” route followed by Senator Feinstein, it can be argued that Lake Tahoe’s increasing air temperature is a significant contributing factor to the Lake Water temperature:
Source: NASA GISTEMP
But then you see what the measurement station looks like. Then of course that station’s data purity is brought into question for reasons of siting as well as local development nearby in Tahoe City.
Of course, we don’t know exactly what the magnitude of contribution to warmer temperatures at this station from those siting issues are, and the burn barrel has since been removed from the USHCN station enclosure shortly after I highlighted it in June 2007. The tennis courts surfaces nearby may have an effect on air temperature also.
What is important to note though, and this fact is lost on many politicians, is that the lake itself, as a large solar insolation heat sink, has more effect on local air temperatures than the other way around. The reduced clarity contributing to increased water temperature issue likely is a factor in the USHCN weather station data, given it is just a few feet from the lake.
And that brings us back to the quote from the original newspaper article:
Since 1970, the water temperature of the lake has risen by about three degrees, according to scientists.
Eyeballing our Tahoe City USHCN station graph from GISS above, it looks like we have a trend since 1970 not far from that value. Using air temperature from our world renowned center for global warming data, NASA GISS, one can certainly draw a correlation between the air temperature of the Tahoe City station and the water temperature of the lake.
But as we’ve heard so many times, correlation is not causation.
Feinstein appears to completely miss the physical connection between increased water temperature and the Lake Tahoe water clarity cause she championed. Now the need for an additional $390 million. Before she spends more citizen’s money chasing this global warming issue, let us hope she gets some “clarity” on the issue soon.
Ever wonder where some of that money goes? See TERC’s headquarters. Nice digs for studying a lake. The field station is not too shabby either.
While TERC has a really nice LEED certified HQ, I can’t find a single publication on their website about water temperature and turbidity. Unfortunately I can’t scan the content of the papers on their website since so few are posted in full text form, just titles.
Given the huge public relations effort to preserve Lake Tahoe’s clarity and, by the view of the lake’s most famous patron, Diane Feinstein, and the apparent connection to global warming, one would think that a water turbidity-temperature study would be something they would want to pursue. Either to confirm it, or to rule it out.
If I’ve missed such a study, please feel free to post it in comments.
Addendum: Additional References on turbidity (originally from comments)
Here is one where reflectivity is examined in the context of turbidity.
Citation: Witte, W. G., C. H. Whitlock, R. C. Harriss, J. W. Usry, L. R. Poole, W. M. Houghton, W. D. Morris, and E. A. Gurganus (1982), Influence of Dissolved Organic Materials on Turbid Water Optical Properties and Remote-Sensing Reflectance, J. Geophys. Res., 87(C1), 441–446.
http://www.agu.org/pubs/crossref/1982/JC087iC01p00441.shtml
“From these data it is clear that dissolved organic materials decrease upwelled reflectance from turbid waters. ”
Here is a primer on suspended solids in water from the City of Boulder Water Quality Monitoring:
http://bcn.boulder.co.us/basin/data/BACT/info/TSS.html
“High TSS (total suspended solids) can also cause an increase in surface water temperature, because the suspended particles absorb heat from sunlight.”
Here is another identical passage from the New York Harbor Survey that cites TSS and water temperature:
http://www.nynjcoast.org/NYCDEPHarbor_survey/docs/water_clarity/total.htm
“High TSS can also cause an increase in surface water temperature, because the suspended particles absorb heat from sunlight.”
From Brockport University
http://vortex.weather.brockport.edu/~jzollweg/oakorchard/docs/waterquality.pdf
On page 1 under TDS (Total Dissolved Solids):
“Similar to TSS, high concentrations of TDS may also reduce water clarity, contribute to a decrease in photosynthesis, combine with toxic compounds and heavy metals, and lead to an increase in water temperature.”
For a fairly recent and mostly comprehensive study of Lake Tahoe’s warming, see Coats et al 2006
http://www.springerlink.com/content/6384855p5513l393/fulltext.pdf
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I work monitoring wildlife in the Tahoe National Forest. I look at annual changes in snow pack as part of my analysis on the changes in bird populations. I also like to swim the lakes in the Lake Basin area. It is very obvious that the lake waters stay cool while being fed by snowmelt but then will warm quite quickly once the snow has melted. The highly publicized study did never took into account the affect of snow pack. They simply assumed AGW attribution. If you look at the 100 year record of snow pack for the month of April on nearby Mt Rose, you will find the peak year for snow pack was 1970 with a declining trend over the past 35 years ( 1970 to present was the time of the warming study). The snow pack correlation would explain Lake Tahoe’s warming trend just as readily as Tahoe City’s rising temperature trend. The article emphasize the warming was spreading to the depths of the lake. The mechanism for this warming is harder to explain if you attribute it to atmospheric warming, but more readily explained by less cold water is feeding the lake depths.
When the article was first written I emailed a few challenges to it but never heard from the authors. The SF Chronicle editor responded to my email but was content to accept the attribution of AGW. Judging from the low snowpack in the early 1900’s I would expect any water temperature trends would actually show cooling from 1900 to 1970, but I didn’t readily find the data to test my hypothesis.
I would assume that turbidity would be a result of warming and increased alagal growth.
Hope this post was sent to Fenstein…
Sadly, Feinstein is also my US Senator.
It is the forest practices of clear-cutting followed by the shutdown of most legitimate logging, coupled with 100 years of forest fire suppression that has led to the ugly conditions of our forests.
The same interests that leveled the forests in Oregon waltzed on in to Calif. and proceeded to ravage the place. We HAD sustainable yields and excellent trees.
Not any more.
Feinstein needs to look in the mirror.
Where was she when the forests were being leveled, and where was she when the burnt areas were lawsuited into non-recoverable tinder-box brush patches?
Out to lunch.
I’ve been on (and in) and over Tahoe for years. From my own Sailor’s and Pilot’s eye the
turbidity issue is real. Also what about UHE ? Iknow the place has got to have some issues there. a warm summer day and the radiation of all that asphalt….
With more population around any lake and the increased runoff which most likely has phoshates from sewers and agricultural activities the algae population in the lake will shoot up proportionaly. The increased algae will make the temperature of the surface water go up since they absorb much solar radiation (lots of non-photonic deactivation mechanisms in plants… thermal deactivation). An algae layer will also give a stagnant water above that does not get mixed well with the bulk water of the lake. On one hand you get a low local CO2 concentration and higher O2. However, due to the increased temperature, the actual concentration of oxygen in the water is low… this is why fish die in lakes with algae bloom problems. The algae and hot water layer keeps the deeper water from getting oxygen. On the other hand, a cristal clear lake without any algae could be a sign of acidification, which is also bad for aquatic life.
Robert Wood (15:31:48) :
I visited the US in 1993 with a mate of mine. We went to Lake Tahoe and had a greatood time. We played a round of golf there and by the time we were on the last green, it was just about pitch black. We heard a shout from the tee: “is there anyone on the green?”
We met a local guy there who had a boat and he took us on a trip on the Lake the next day – a great hangover cure that was. He told us that the local Indians used to ‘bury’ their dead on the Lake because the water was so deep. He also told us that on occasion a body will still float up to the surface.
Jimmy Haigh (23:59:51)
“greatood”? Sorry – I wrote “good” initially then changed it to “great” but my keyboard is a bit dodgy. My mouse has seen better days as well…
excellent article Anthony…. Good explanation of cause and effect.
The lake’s surface water warming due to turbidity, the local atmosphere warming due to the heat released by the warm lake surface water, then being recorded by the nearby temperature station. The results then being deliberatly misrepresented or confused by the naive Senator Feinstein.
It is impossible for the temperature of the water in the lake to have a 3 degree rise due to a transfer of heat from CO2 in the atmosphere. It would be interesting to see if an AGW proponent could show that mechanism…. do any wish to try?
Storm induced turbidity currents are important mechanisms for introducing sands into water. The following picture is an example of deep water ‘turbidite’ sands from Anzoategui State in Venezuela. The rocks here are Upper Cretacous in age, approximately 75 million years old. In general the sands ‘fine upwards’ and a typical sequence goes from coarse sand through to silt. After the turbidite has been deposited, background sedimentation of mudstone continues.
http://i919.photobucket.com/albums/ad34/Jimmy1960/Taguayasands.jpg
Turbidite sand bodies are important oil/gas reservoirs. The Paleocene Forties Formation of The North Sea is a good example.
I seem to recall that the Grand Banks of Newfoundland earthquake of 1929 caused a turbidity current which severed several undersea communication lines. I’d look for a link but the baby has just woken up and normal service has to resume…
Mike D. (18:00:04)
Someone once said the government is the problem.
$390,000,000.00, hmmm, how much senior health could that buy?
For a discussion of the greenhouse gas emissions from forest fires, see Bonnicksen, Thomas M. The Forest Carbon And Emissions Model. 2008. The Forest Foundation, Auburn, CA, here:
http://westinstenv.org/ffsci/2008/03/14/the-forest-carbon-and-emissions-model-fcem/
FCEM is a model (what else?) but it is useful making rough calculations. For instance, one acre of forest burned severely emits the GHG equivalent of 9 to 15 cars driven all year. Then as the fire-killed (but not consumed) wood rots, an addition 3 to 4 times that much is emitted (over the next few decades).
Considering that 5 to 10 million acres of forest is burned in wildfires in the U.S. each year, the GHG equivalent of 150 to 600 million cars is emitted.
Using FCEM I calculated that in 2007 in Oregon 56 teragrams of CO2 was emitted by forest fires (a teragram is 10^12 grams, or one million megagrams; a megagram is one million grams and is also called a metric tonne). That was approximately the same amount emitted by the transportation, waste, residential, commercial, industrial, and agriculture sectors combined (in Oregon). Reducing forest fire acreage by half would reduce total CO2 emissions by 25% in our state.
Personally, I am not all afliver to reduce CO2 emissions because I am a climate realist. However, reducing forest fire acreage would benefit watersheds, soils, wildlife, public health and safety, and the economy, as well as dozens of other natural and human environmental resources (such as reducing erosion and improving water runoff quality).
Ref Sea Turbidity Question
You may not have seen this http://www.aslo.org/lo/toc/vol_46/issue_5/1100.pdf
Regarding turbidity currents, I should also point out that not only can they redistribute sand and silt from shallow water or continental environments into deeper water, be it lacustrine (as in the case of Lake Tahoe) or marine environments but they also introduce land based or shallow water biota into deeper environments. They also redistribute warm surface waters into cold deep environments. Storms are the major source of turbidity currents but earthquakes can also cause them.
Here’s another photo from the Pliocene age outcrops on the south coast of Trinidad of a possible earthquake induced coarse water deposit of Pliocene age in Trinidad. Some of the sediment blocks here were up to 100m in size! Here, coals and fluvial flood plain mudstiones sit in a very deep water marine environment; perhaps several hundreds of meters. This particular deposit was possibly caused by a tsunami of the same magnitude of the 2004 Indonesian event. It may also have been caused by a hurricane.
In the photo, (in which yours truly appears!), we can see a chaotic extremely coarse grained and poorly sorted unit. The large block above my head is a clast of shallow marine sandstone and the smaller blocks are a mixture of shallow and non marine sediments. The depositional environment of the unit was deep water – in the order of a couple of hundred metres as evidenced by deep water microfossils.
http://i919.photobucket.com/albums/ad34/Jimmy1960/mdb2.jpg
It is MUCH easier (and more popular) to blame it on Global Warming that to actually tackle the problem. How do you think this would go over: Completely eliminate all towns around Lake Tahoe. Take out all the concrete and asphalt, replant trees. Remove all storm drain systems. Oh, and you have to make that a joint project with Nevada.
Once that is done, both the turbidity and lake level issues will have been (temporarily) addressed. Lake levels because instead of seeing huge amounts of water running into storm drains, into the lake, raising the level to spill down the Truckee River, the water will percolate into the ground and slowly filter out over the course of the summer from springs maintaining the lake level by being added to the lake gradually rather than being channeled through concrete pipes to the lake immediately.
But there is another issue. In general, Lake Tahoe and other Sierra Nevada lakes are at record high levels in a geological timescale. There are trees submerged under tens of meters of water where they once grew on dry land. What we consider “normal” rainfall patterns are actually quite wet by long-term standards. The Sierras have experienced what we would call “mega droughts” that have lasted centuries during this interglacial period. So our idea of what is “normal” is based on about a century and a half of people actually living there during an abnormally wet couple of centuries.
Politicians have no sense of scope on a geological timescale. Their scope is limited to the time to the next election. But I suppose that is OK because most people have no idea they have been living in a rainfall boom time and when things get back to more “normal” patterns, they are going to have to blame someone for it.
DiFi just wants to make sure they don’t blame her.
Just one comment/question. Where do these clueless politicians keep coming from? Is there a college to teach dropouts/idiots to become politicians? One thing is certain; none of them could hold down a real job.
@ur momisugly “van is from the maintenance man”: I guess before 1960, here was no maintenance-man-van to influence the temperature.
Why not go the whole hog and say:
‘These folks are spending millions of my tax dollars fuelling the construction boom, talking about global warming, but not actually doing the studies they are tasked to carry out to understand the CAUSES of recent temperature rises at Tahoe?’
Or am I being a tad brutal for our understated American friends?
Excellent post, Anthony. You have the nose of a super detective on the trail of evidence to determine the science of the matter. $390 million smackeroos for “additional preservation projects” at Lake Tahoe, hmmm. Perhaps more cushy buildings where academic “researchers” into global warming can do their stuff. I like the following two sentences:
“Unlike other officials, Feinstein blamed global warming for the degradation of Lake Tahoe.
“The real culprit in my mind is global warming,” she said.
We all know by now that Sen Feinstein has funneled billions of dollars to her husband Richard C. Blum, chair of the board of CB Richard Ellis Group (CBRE), “the world’s largest services firm”; “a multinational real estate corporation”; “a global leader in commercial real estate services”. The latest was legislation for $25 billion in taxpayer money to a government agency that had just awarded her husband’s real estate firm a lucrative contract to sell foreclosed properties (not in CBRE’s “commercial” expertise) at compensation rates higher than the industry norms. Lots more: http://www.washingtontimes.com/news/2009/apr/21/senate-husbands-firm-cashes-in-on-crisis. See more goodies on the crash of CBRE’s share prices; Blum buying at the bottom when CBRE’s contract was approved; prices have increased around 300%.
I am hoping that other readers have information on this couple’s sleaze in the carbon trading market. UC Berkeley now has a Richard C Blum Center for Developing Economies. Dr. Stephen Chu is a Blum Center Trustee. Al Gore was a keynote speaker in April of this year. One aspect is Live Climate, a “growing [voluntary] commodity market [in carbon offset purchase] represents a valuable new source of financing for sustainable development.”
Furthermore, the sixth annual Brookings Blum Roundtable for leaders from the climate change and global development communities convened 7/30-8/1 in preparation for Copenhagen in December. “Policy-makers must now think creatively to realize their goal of revitalizing the global economy through low carbon growth models….the roundtable forged sustainable solutions to solve the climate crisis in a way that revitalizes the global economy and lifts the lives of the poor.”
“Turbid” in its figurative meaning is “confused, muddled”. These global corporate types who have taken over the U.S. government, the U.S. media, and academia want to keep us confused and muddled about their real intentions — unimaginable wealth for themselves under the guise of helping those in poverty and saving the world from GHGs while throwing a few bones — $390 million — to their lackeys.
http://earthobservatory.nasa.gov/IOTD/view.php?id=39891
John F. Hultquist (17:24:12) :
“I realize the burn barrel has been moved and maybe no longer used but I wonder what they burned there. Our county in Washington State no longer allows burn barrels, in part, because folks tend to try to burn all sorts of things that are better sent to a landfill and because the barrels are usually not constructed to facilitate complete combustion. ”
Notice that the barrel is sitting on a wooden pallet. Clearly it was not used for burning within the enclosure, but merely stored there.
I have no idea of the size of the lake you are talking about but another problem that I have not seen discussed is stratification. The temperature of the top layer will alter quite rapidly in accordance with the weather – sunshine, wind, rain, season. Temperature then drops quite dramatically at greater depths and becomes anaerobic. When the air temperature drops significantly after a hot spell, there is a corresponding drop in temp of the top layer. If this falls below the temp of the water below, this can cause inversion with anaerobic water coming to the surface causing dramatic fish kill.
There is a simple method to alleviate this by drawing the water from depth to the surface where it is naturally oxygenated. If this is done slowly but constantly, the water will be more healthy at much greater depth and the turbidity will be considerably reduced. There are simple wind powered machines that can do this. It floats on the water, suitably anchored, with a vertical pipe, say 12 inches in diameter, going down to the required depth. A propellor at the top just below the water surface is driven by the wind drawing the initially anaerobic water to the surface. A large lake would naturally need quite a few of these but I believe that one unit can successfully transform a 2 acre lake. Lake Aid is based in the USA and provides these products – or did so a few years ago.
All the best solutions are the simplest and cheapest!
On the other hand, turbidity is also caused by the natural process whereby necessary nutrients (iron rich dust) being injected (or nutrient rich sediment being brought up) into surface layers so that the food chain can be maintained. Clear lakes that stay clear usually have few fish at hand. Why? No food source. High glacier lakes in the Wallowas are stocked with fish every year to enhance tourism (when the budget allows) because otherwise, there is no possible way for fish to get there and there is not enough of a food chain to sustain a fishable lake.
It is quite possible that natural forest cycles (decadal growth and burn) create the necessary wash of nutrient rich soil into large bodies of lakes which in turn maintains its food chain. Fire supression, or logging practices that do not mimic natural fire cycles, reduce and disrupt the food chain.
In summary, natural turbidity cycles are a necessary food chain mechanism. To disrupt that by over-enthusiastic control measures, or to overwhelm it by using the lake as a constant water runoff garbage dump, will result in a disrupted food chain with consequences throughout the flora and fauna ecosystem.
After reading clarity and heat Buffalo Springfield comes to mind–and I enjoy reinterpreting their masterwork for the climate change saga:
“There’s something happening here
What it is ain’t exactly clear
…
What a field-day for the heat
A thousand people in the street
Singing songs and carrying signs
Mostly say, hooray for our side”
Listen to the whole thing, if you got it. Or Youtube it:
– Mike
After Yellowstone was allowed to burn naturally, much understanding was developed about fire behavior. Where fuel loads were high, the fire clearcut the forest into meadows. Where fuel loads were low, the fire cleared the forest floor but did not harm as many trees. It appears in natural cycles that clear cutting fires are as necessary as forest floor fires. Both seem to enhance the natural meadow and forest combinations seen in untouched and allowed to burn forests. These cycles should be studied and mimicked in managed forests.
To do this, I think that all federal forests should be returned to the states and the federal budget sent with the forests. Each state should then be allowed to create a state forestry department that works with specific forest managers and loggers to develop logging practices unique to each forest type and that both sustains and utilizes forestry products for the benefit of forest product companies, loggers and the surrounding communities.
Disband any and all Federal forestry departments, including oversite of national parks, and return lands and control to states.
Perhaps the real problem for Lake Tahoe is that she has not found a way to funnel cleanup money to her family’s defense contractor corporation?
http://www.indybay.org/newsitems/2009/05/14/18594789.php