nitinat; methane lake

[jump'njibe'njim]

On my last trip to Nitinat I was surprised to learn that the Nit is a Methane Lake! Not only that, but it's meromictic and could produce a limnic eruption! If you're interested, check these words out at Wikipedia, as well as Lake Kiva.
A nice fellow with his family (didn't get his name) and I were talking about the big trees with stumps that are on the beach. He told me how they came in during a really, really big storm about three years ago (?). The same storm caused methane gas dissolved in the bottom of the lake to come to the surface, killing the fish in the hatchery. Government scientists and divers came to investigate the kill and realized that Nitinat is one of a few methane lakes in the world. As he explained it, the far side of the lake is quite deep, having cracks on the bottom that zig-zag down quite a ways. Logging debis, having acccumulated in great quantities, rots away in the fresh water from the streams which sinks below the salt water that ebbs and flows with the tide. The fresh water is trapped down there with methane building up constantly from the rotting wood. Pressure at depth keeps the gas dissolved in the water until it rises to the surface where bubbles of methane form. The storm was so fierce that it caused the lakewater to roll, bringing the fresh water with it's dissolved methane to the surface, killing the fish. If it hadn't been very windy, the gas could have filled the valley causing people and animals to die of asphyxiation as they did in large numbers in Africa at other methane lakes.
So watch out for bubbles on the far side. It could get, well, interesting.
If anyone knows more about this, or if the nice fellow who told me about it reads this, I would be interested to know more. It's just too wild and crazy to ignore.

[Mattdog]

So when you think you smell noxious farts wafting over from my tent, it isn't me at all. It's the legendary Nitiness Fartilator.

[KUS]

I've been told trees (wood) apparently don't decay (quickly?) when submerged in fresh water.....which is why you can still salvage huge sunken stumps/logs out of Harrison, Stave, Cowichan and other large lakes that used to float booms and make a killing with the awesome straight grain first growth timbers that are waiting below

[more force 4]

Wood rotting has to be only part of the story. All lakes have wood rotting but very few have a methane buildup. I THINK its to do with the layering. Anyone else chime in - Randy K?

[mortontoemike]

I'm not sure it's "methane" that is the problem. H2S, hydrogen sulphide, is the problem apparently. There is an MSc thesis on Nitinat at:

http://supercritical.civil.ubc.ca/~efmweb/glamont/

published by a student in Civil Eng. at UBC. It discusses the deep water chemistry, H2S, and upwelling events at the lake. See pages 19-20 regarding the anoxic nature of the lake at depths and the history of upwelling events releasing H2S causing trouble at the hatchery.

[downwind dave]

203m deep! i guess ill never get those sunglasses back.

[KUS]

the several sets of glasses, those fins, that 1990 universal (good place to find out the thing sinks when adjusting mast track mid lake, was a good swim).....yer not alone, DWD

[Mattdog]

Kus how do you afford it? You're like the component destructor man. .

[~~~~~4j~~]

Interesting read. I have copied the history section below:

1.8 History of Anoxic Water Upwelling

Localized upwelling events have been observed on the lake by both the Ditidaht First Nations and Nitinat Fish Hatchery employees, and have caused significant fish kills in the lake. Upwelling events are usually localized and are often detected by smell (‘rotten egg’) or by sight (surface waters turn a ‘brown color’ - Shortreed, 1987). The record of
events is incomplete as there has never been continuous monitoring of the lake, but does provide a starting point for examining conditions that lead to upwelling events (Table 1.8.1). Ozretich (1975) suggests two possible causes leading to upwelling; either strong outflow winds or coastal ocean upwelling coupled with high tides leading to deep water
renewal.

In the first case, strong winds blowing down the long axis of the lake impart a shear stress onto the surface that ‘pushes’ the surface layer towards one end of the lake. If sufficient sustained winds are present during times of weak stratification, it is possible that upwelling of anoxic water will occur at the upwind end of the lake. On Nitinat Lake an upwelling event due to wind shear is most likely to occur in the late fall after a dry summer. The upwelling event of October 1972 was most likely caused by the combination of weak stratification and strong NE winds (Ozretich 1975). In the second case, Ozretich (1975) suggests that Fraser River discharge may play a role in upwelling due to its influence on the intensity of the seasonal halocline in the Stait of Juan de Fuca. A lower than normal discharge will result in a weaker halocline off the south west coast of Vancouver Island. This allows for deeper penetration of the wind stress and results in a greater horizontal Ekman transport of water, enabling more intense upwelling to occur in the event of strong wind forcing. Strong winds may also create higher than predicted water levels through set-up and surge of surface water. If coastal upwelling were to occur during higher than normal incoming tides, it is possible that some of this dense water will enter the lake and, despite mixing across the sill, remain denser than the bottom water, thereby triggering an upwelling event as it sinks into the lake and displaces existing waters. (Ozretich, 1975). The 1970 and 1987 events were likely a result of this deep water renewal mechanism.

Upwelling induced by wind shear has been problematic on Nitinat Lake. First, the density stratification is weakest in the late fall, which coincides with the time that spawning fish are returning to the lake (Ozretich 1975). Second, it is more likely that NE winds will produce upwelling than SW winds since anoxic water is deeper at the south end of the lake than the north (Broenkow, 1969). This is unfortunate due to the fact fish pens used
by the Nitinat River Hatchery are located at the north end of the lake.

Table 1.8.1 – History of recorded upwelling events at Nitinat Lake.
Due to the remote location of lake, it is likely that many upwelling events were not recorded, and that this record is incomplete.
Date Location Comments Source

July 2, 1970 Near sill Very high tides (H=3.27m)
Strong westerly winds
Ozretich (1975)

October 13, 1970 Near sill Very high tides (H=3.21m)
Light winds
Ozretich (1975)

October 15, 1972 Near head Average tides (H=2.77m)
Strong outflow (Northerly) winds
Ozretich (1975)

October 22, 1972 Near head
(unconfirmed)
Large tides (H=3.56m)
No wind data available

Ozretich (1975)
November 5, 1987 Near head Large tides (H=3.45m)
Light winds
Shortreed et al.
(1987)

March 21, 2002 Near head
(unconfirmed)
Average tides (H=3.03m)
No wind data
DFO Nitinat Fish
Hatchery

March 8, 2003 Near head Average tides (H=2.98m)
No wind data
DFO Nitinat Fish
Hatchery

[jump'njibe'njim]

Thanks for the article, Mr MToe. It's remarkably well done. It all just makes the Nit an even more exotic place. 600 feet deep! Largest salmon hatchery in Canada? Who knew?
Gladly, it's not methane but something safer sounding (I guess). Explosions or suffocation are not likely problems. But it sure is interesting. One would have to admit that the lake is at least, a pretty unique place. It's something to think about while zipping merrily about it's surface.

[mortontoemike]

Well, I don't know about safer.

Hydrogen sulphide, H2S, is a colorless, toxic, flammable gas that is responsible for the foul odor of rotten eggs and flatulence . It often results when bacteria break down organic matter in the absence of oxygen, such as in swamps. Hydrogen sulfide is considered a broad-spectrum poison, meaning that it can poison several different systems in the body, although the nervous system is most affected. The toxicity of H2S is comparable with that of hydrogen cyanide.

Hopefully it will stay at the bottom of the lake!

[kitesurferdale]

It is said that if the lake doesn't turn over for extended periods of time, like a century or more, enough H2S can build up to become toxic to the shoreline inhabitants. So if you or I were to be sailing at the time and it turned over.....death. H2S is the same gas that kills oil field workers from time to time.

[Windsurfish]

And I thought it was all the beans I eat H2S differs from cyanide gas in that when you can smell it it is probably OK, whereas when you can smell cyanide, you are in trouble . At higher (and more toxic levels), H2S is odourless, making it a more 'evil' poison than even cyanide.....

[mortontoemike]

You are supposed to carry pennies in your pocket. H2S tarnishes the pennies by forming copper sulphide (I think). When your pennies start to tarnish it's time to head for home .... or quit eating beans ... one or the other ...

[Windsurfish]

Hmmm maybe I would have more friends if I had a pocket full of pennies