Mono Lake, California, is described in Wikipedia, the online encyclopedia, as follows:

Mono Lake (/ˈmoʊnoʊ/ MOH-noh) is a large, shallow, saline soda lake in Mono County, California, formed at least 760,000 years ago as a terminal lake in a basin that has no outlet to the ocean. The lack of an outlet causes high levels of salts to accumulate in the lake. These salts also make the lake water alkaline.

I visited this natural wonder years ago when its water level was at an all-time low, due to excessive water diversion by the City of Los Angeles. (A legal challenge later provided some remedy.)

The rocks in the photo are not in Mono Lake, of course, but right here in Hardy Pond, just south of Smith Point. The white bands appeared for the first time this winter, stirring my memories of the evaporative deposits at Mono Lake. I took the photo on January 9, 2012, during the brief and only appearance this past winter of ice on the pond.

I’ve looked out upon this scene every day for twelve years, but had never seen those vivid white bands before this winter. Through my window, I can still see them now, three months later in March. They may, in fact, have grown wider. They’re visible when the rocks are dry and sun is on them.

We’ve heard several explanations of the recent sunfish die-off, except the 800-pound gorilla in the room: poor flushing of the pond due to the silting of its outlet channel. This narrow, quarter-mile channel discharges to Chester Brook, and ultimately to the Charles River. Is the pond behaving like Mono Lake, building up natural mineral deposits, or toxins, or decaying organic matter (that depletes oxygen in the water), because it has no effective outlet? A testing program could provide answers.

Fish kills due to natural oxygen depletion (anoxia), though common other times of year, are almost unheard of in the spring, according to MassWildlife. Natural oxygen depletion is a seasonal effect, they say, occurring either in winter during prolonged ice cover, or in summer when water temperatures become elevated — but almost never in the spring. There was ice on Hardy Pond for no more than a few days this past winter, so isn’t it reasonable to look for other causes?

The outlet channel remains silted up two years after the great floods of March 2010. This should be a matter of overriding concern. Both water quality and flood control are dependent on a free-flowing channel. This quarter-mile stretch urgently needs to be cleaned out, as an outside engineering study (pdf) recommended late in 2010, and as an earlier study called for in 2002. As of this writing, more than a year after the recent report, little or nothing has been done.

Update, July 2012: As I reported above, I saw the white bands as late as March of this year, but they vanished after the ensuing spring rains.

See related posts: High Water*, High Water II*, High Water III, and Dead Fish*. See also special page: The Great Flood*. Click image to enlarge it, and browser’s back arrow to close.


3 Responses to Mono Lake*

  1. Robin Mirollo says:

    Something should be done. You’ve got your tell-tale sign of high salinity right there in that photo Ron, and it may very well explain the fish die off. Have you sent this photo and your blog to any responsible agency in your town?

    The fish kill has me thinking about the arrival of the bald eagle. While inarguably noble creatures, bald eagles tend to scavenge more than hunt for food. Do you think the presence of the dead fish may have lured it to the pond?

    • Ron Cohen says:

      Thoughtful comments, Robin. Yes, the white bands certainly look like an evaporative deposit of some kind, but they could be anything, a salt, an alkali, or perhaps not a deposit at all, but a fungus. They really need to be examined.

      Yes, every city official who might be involved in a decision about the pond is on my email list, so presumably they’ve all seen this post. Beyond that, I’ve had conversations with our city councilor about the issue.

      Yes, The Sibley Guide to Birds says that the Bald Eagle, “feeds mainly on fish (often scavenged) and waterfowl captured in pursuit.” By “scavenged” perhaps they mean live fish snatched from other predators, for I’ve never seen a pond bird eat a dead fish. There are no more notorious scavengers than the Gulls, and they won’t touch them. The two dead fish that I photographed are still lying there, on a rock. The Bald Eagles, themselves, are superb fishers, quite capable of catching live fish; in fact, one was seen catching a fish by a neighbor. What’s more, the Bald Eagles were seen first by my neighbor, Becca, back in January, long before the fish began to die off. So, I’m hard-pressed to see a connection between the fish die-off and the arrival of the Bald Eagles.

      • Robin Mirollo says:

        I’m happy to hear that city officials are on the email list. I was merely speculating on the bald eagles’ presence and as you said, they arrived before the dead fish were spotted (or at least before anyone noticed the dead fish). I would like to think the eagles’ presence connotes a relatively healthy Hardy Pond, but without the neccesary testing it’s difficult to say. Nevertheless I hope you and your neighbors continue to enjoy your wonderful eagle guests.

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