There's no scientific name for it. So hydrologists like Doyle Stephens use the same name the rest of us do: Lake Stink.
After a century and a half in the Salt Lake Valley, Utahns have not yet come up with a better description. Or a way to get rid of the smell. Lake Stink, in fact, is a pungent reminder that, for all our technologies, we still are at the mercy of bacteria and a strong breeze.At its odoriferous heart, Lake Stink is about decay. But to fill up the valley with Lake Stink's unique aroma of rotten eggs and dead-sea creatures, it's also necessary to have a hefty wind blowing in from the north or northwest.
So far, the summer of 1997 has proved to be particularly smelly, with several pungent episodes in July and July. Unusually windy days were partly to blame.
Not much lives in the briny Great Salt Lake. But what does live eventually has to die, including a substance usually called "blue green algae" - actually a type of stringy bacteria called cyano-bacteria.
Cyanobacteria, as well as real algae, flourish when there is plenty of light, warm temperatures, a good supply of nutrients and just the right amount of salinity.
"The warmer it gets, the more the biology gets cranked up," explains U.S. Geologic Survey hydrologist Stephens.
And the warmer it gets, the more that process includes the smelly business of death. As the cyano-bacteria get old, die and decompose they become lunch for other kinds of bacteria in the lake. In the process, these other bacteria change the organic sulfur in the algae and cyanobacteria, and sulfates in the water, into sulfides such as hydrogen sulfide - the source of the rotten egg part of Lake Stink.
"It's the smell of recycling," says Stephens.
The human nose is especially sensitive to hydrogen sulfide. It takes only parts per trillion to be noticed - nature's way of providing an early warning, since at the parts per million range (roughly a thousand parts per million) it can be deadly.
The smelliest of the algae and cyanobacteria in the Great Salt Lake is Nodularia spumigenia, says Brigham Young University botanist Sam Rushforth. Nodularia grows best, he says, in years when the salt content of the lake is lower than normal - in other words, in years of heavy snowmelt.
But plants aren't the only things decaying at the lake. Decomposing brine shrimp and brine flies release two gases whose names "pretty much describe them," says Stephens: cadaverine and putrescine. The two chemicals are part of a bigger class of smelly chemicals called mercaptans. One of the most famous mercaptans, although not by name, is that released by skunks.
But all those foul smells would only affect noses right near the lake, and in fact only near the shoreline, if it weren't for an occasional strong wind.
When the wind blows from the north or northwest it can stir up those gases and send them wafting across the valley. The wind can churn up the lake water, pulling decomposed matter up from the lake bottom, and it can also stir up the decomposed matter on the shore. As the lake recedes each year from its springtime high levels, more and more of that matter is exposed.
That's why Lake Stink is usually most pronounced in the late summer and fall, even into November. The valley then gets a respite during the winter months, when biologic processes slow down and some of the lake freezes.
When the world comes to Salt Lake City in the winter of 2002 it shouldn't be smelly at all.