INDEPENDENCE — The dense forest that buffers the Verdigris River from barren bean and corn fields tells the story of last May's devastating flood in southeast Kansas.
The flood destroyed the crops, and their remnants hang lifeless from the trees some 30 feet up a steep hill from the river. That's how far the river rose.
New crops will have to wait another year, but already the Verdigris is on the mend, with help from the freshwater mussels that for centuries have worked to keep the water clean and provide food for the river's fish and other wildlife.
As a canary once warned miners of a precarious dwindling air supply, mussels act as an indicator of a river's water quality. The stronger the mussel population, the cleaner the water.
The hard-shelled creatures - which live submerged along riverbeds throughout the state, including along the Kansas River - are sometimes only noticeable by the small siphons that draw and expel water. A single mussel can filter 8 gallons of water a day.
But freshwater mussels are struggling to survive. Today, mussels are among the largest group of federally threatened or endangered species, according to the U.S. Fish & Wildlife Service. More than 70 percent of the nearly 300 species found in the United States are listed as threatened or endangered.
There have been 45 species of freshwater mussels historically found in Kansas, 24 of them are on the federal or state list as being a concern and four species are thought to be extirpated from state waters.
Environmentalists say nearly a century of harvesting, pollution and changes to the mussels' habitat have led to today's situation.
Freshwater mussels have two shells connected by a hinge-like ligament. Adults range in size from a small stone to as big as a pie plate. Mussels can live to be 100 years old; the ridges on their shells reveal their years, like a tree. By their siphoning actions, mussels filter bacteria, algae and other small particles.
While mussels' shells are rugged-looking on the outside, their insides are beautiful pearly purples, pinks and whites.
As settlers moved west and towns sprung up along major Midwestern rivers, mussel shells became important in the garment and jewelry industry, said Bryan Simmons, terrestrial/aquatic ecologist for the state Department of Wildlife and Parks.
Shells were harvested and shipped to factories, where they were turned into buttons and jewelry. This became a major industry along eastern Kansas rivers such as the Verdigris. Waste button shells also were used in building foundations and bases for sidewalks and roads.
Some 85 million mussels were removed from Kansas' Neosho River in 1912, which represented about 17 percent of the nation's total pearly products, Simmons said.
"Plastics in the 1940s helped to save the mussels," added Edwin Miller, wildlife biologist for Wildlife & Parks. "Plastic buttons were cheaper and easier to make than buttons made from a mussel's shell."
But between pollution and harvesting, the damage had been done.
Mussels continue to be harvested in the United States. Their shells are sold to Asian markets and are used as a host for beads that are placed inside to create pearls.
Kansas lawmakers enacted a 10-year ban on harvesting mussels in 2002. Four people have since been prosecuted, but each fled the state before trial, say state authorities.
Not yet endangered
Miller and Simmons recently returned to a spot along the Verdigris where they surveyed the mussel population in 2003. Wearing waders and aqua socks, the scientists quickly pointed out hundreds of freshwater mussels lining the bottom of the shallow river. The mussels were prospering despite the May floods, they declared.
"The flood did not have much of an impact on the mussel here," Miller said. "The area has good bedrock, which stabilizes the gravel. Mussels are adaptive to that. The problem is when we affect the river's flow."
The 2003 survey found 149 mussels in one square meter. The average was 56 per square meter, and the river is likely still in that range, they said.
The last thing Miller and Simmons would want is for mussels to be listed as federal endangered species.
"Keep them common where they are still common," Miller said. That way, he added, he and Simmons won't have to jump through political hoops that the government requires when dealing with endangered creatures.
For instance, the state has a hatchery that is helping to reintroduce mussels in areas where they previously struggled.
Zebra mussels, which are proliferating and causing problems in some Kansas reservoirs, are not a concern in the state's rivers, Miller and Simmons said, because the rivers see less of the boat traffic that can spread the invasive species.
Better water quality
Mussels in the Spring River in Cherokee County in southeast Kansas - where zinc and coal mining thrived was the major industry until the 1960s - are not doing as well as those in the Verdigris. There, a recent Kansas Department of Health and Environment survey determined that mining nearly killed off the mussel population.
But some native mussel species are returning, said Bob Angelo, a KDHE environmental specialist, who headed the survey.
"We're seeing a gradual improvement in that area as a result of federal, state and tribal remediation," Angelo said. "When you have an area that is contaminated to that extent, you have to look at long-term remediation. It is very important that where you still have some of these pockets (of improvement)."
Angelo credits overall water quality improvements to the Clean Water Act of 1972 that set standards for, among other things, waste water discharges. The Act also led more recently to grants and low-interest loans for improvements to existing treatment plants and the design of new facilities.
Also doing their part to clean Kansas' rivers are the fresh water mussels.