It is estimated that 143 mussel species are native to the Mississippi Basin.

Their names are fantastical—as colorful as their nacres:

Today, 15 native species are extinct
41 are endangered
2 are threatened

Overall, mussel populations have declined 70% in the last 100 years.

Saokio-tapi (Anglicized: Blackfeet) mythology refers to a mussel shell as the container in which all the world's water is held. It is an apt description.

Freshwater mussels have high ecological significance, providing filtration, substrate stabilization, and oxygen.

When describing mussels, western scientists also turned to myth, calling them Naiads, after the enigmatic and often mischievious Greek water spirits.

When an irritant, such as a parasite, or a grain of sand, enters the shell of a freshwater mussel, the mussel forms a hard coating of nacre, otherwise known as mother of pearl, around the object. Over time, a pearl is formed.

An 1870 fasion advertisment published by Currier & Ives that prominently features pearls.

In the late 19th century, pearls were considered an upretentious form of jewerly, as suitable for queens and millionaires as for commoners.

Coincidentally, in 1890, the average monthly wage for a hired farm hand was $18.33.

However, a single freshwater pearl could fetch anywhere from a few cents, to hundreds, even thousands of dollars. Particularly large, or colorful pearls were often announced in newspapers, sometimes several states away.

A Kansas newspaper notice of a prominent pearl sold in Pairie du Chien, Wisconsin.

If a stretch of river became known for large pearls, such as the Fox River in Illinois, Pearl Rushes typically followed.

New York Times article from September 28, 1902.

The lure of pearl riches decimated local mussel populations. While some did find fortune, most pearlers switched occupations after rushes subsided.

Some, however, turned to a different part of the mussel for their fortune...

According to legend, in the 1890s, a German immigrant named John Boepple cut his foot on a mussel in the Sangamom River, and then had a brilliant thought: why not use the shell to make buttons?

John Boepple cutting buttons. Year unknown.

In reality, Boepple had been a button manufactuer in Germany, and was lured to the Upper Mississippi by the prospect of abundant mussel resources.

In 1890, with aid from the McKinley Tariff, which raised prices on imported marine mussel shells, Boepple started his own button cutting factory in Muscatine, Iowa. Within 10 years, Muscatine was the button capital of the world, housing dozens of factories, and buying shells from up and down the Mississippi.

Beopple's Button Factory in Muscatine, Iowa, 1902.

4th Street, Muscatine, Iowa, paved with discarded mussel shells. 1902

Over 38,000 tons of shells were harvested in 1908, and the industry itself peaked in the 1910s.

The industry was so vital to the economies of river towns, that when initial scientific reports suggested that mussel populations were being depleated at unsustainable rates, the U.S Department of Fisheries promised to breed and restock mussel populations themselves, rather than regulate the industry.

Weber and Sons Quality Buttons, 1918

These efforts failed.

Beopple himself struggled to compete with the rapid growth of new technology, and watched the industry surpass him. In 1911, he cut his foot on a mussel while wading in the Mississippi, and later died of infection. When the Naiads of Greek Mythology were angered, they often sought vengence.

Prior to European colonization, mussels carpeted many rivers in the Mississippi Basin, especially the Tennessee and Cumberland.

Lock and Dam No. 19, AKA the Keokuk Dam, in the 1980s.

In 1910, construction began on Lock and Dam No. 19, otherwise known as the Keokuk Dam, in Keokuk, Iowa. The dam was first large dam construction on the main channel of the Mississippi, and one of the largest hydroelectric dams in the world at the time.

For many years, the Ebonyshell (Fusconaia ebena) was the staple mussel of the button industry. But ebonyshells relied on the migratory skipjack shad, and only the skipjack shad, to transport their larva. The Keokuk Dam was impassible to Skipjack, and without their assistance, ebonyshell populations upstream of the dam could never replenish.

Interior of an Ebonyshell (Fusconaia ebena).

But the most catastrophic effect of dams on mussel populations is their fundamental alteration of habitats. Changing temperatures and reducing flows. For sensitive mussels, these changes were often impossible to overcome.

Tennessee Valley Authority propaganda poster from World War II

The dam construction work of the Tennessee Valley Authority, and the similar dam building efforts it inspired across the west, changed the landscape of American waterways. And its mussels.

Of the 15 species of extinct mussels in the Mississippi Basin, all of them were native to the Ohio, Tennessee, and Cumberland rivers in the Eastern Basin.

By the 1950s, the button industry was dead, dam construction was occuring at the same breakneck pace it would for the next half-century, and freshwater mussels everywhere were paying the price of progress.

Cargo ships, staples of the global economy, often unwittingly carry passengers in their ballast water, that are then released when the water is discharged. Prior to 1996, there were no restrictions on ballast water discharge in the United States. In 1988, this lack of regulation led to the arrival of a devastating invader: the Zebra mussel.

Zebra mussels infesting a current meter on Lake Michigan, 2007

Quickly, the small opportunistic mussels reaked havoc in Lake Michigan, and quickly spread throughout the Ohio and Upper Mississippi rivers.

Unlike most freshwater mussels in the Mississippi, Zebra mussels attach to any hard surface they can find, be it substrate, or other mussels. Due to their massive numbers, Zebra mussels reduce the availability of nutrients and plankton in an ecosystem, causing major stress on native mussels

Zebra mussels attached to a larger mussel.

In northern waters, Zebra mussels are devastating, in some cases extirpating already stressed native mussel populations entirely. However, Zebra mussels in southern, warmer waters may have difficulty establishing, meaning that native mussels in the southern basin may escape their effects.

But for many streams, and especially lakes, there is no recourse.