Nature’s Water Filters Vanishing : Mussels: Pearls of the River in Peril
Ecologist Richard Sparks has worked the muddy bottoms of the Mississippi and Illinois rivers studying freshwater clams and mussels--nature’s water filters--and he doesn’t like what he sees.
The shelled creatures are disappearing from their native North American riverbeds, where they spend their lives filtering polluted water through hairline openings in their shells. Scientists cite two reasons.
One is massive die-offs, as yet unexplained.
The other is the voracious appetite of the Japanese cultured pearl industry, which grinds tiny beads from mussel shells and embeds them in oysters to produce pearls. Overzealous shellers are staging a rush on U.S. mussel beds, further harming supplies.
“There used to be 50 species of mussels on the upper Mississippi, and now there are only 36 to 38 left,” said Sparks, a river ecologist with the Illinois Natural History Survey at its river research lab in Havana.
Sparks is one of dozens of scientists and others in states across the Midwest concerned about the plight of mussels and clams, which come in all sizes and shapes and live as long as 50 years.
“I’ve been buying shells on the Mississippi River for 14 years,” said D.E. (Butch) Ballenger, owner of the Mississippi Valley Shell Co., in Muscatine, Iowa. “I plan on doing this a long time. That’s why me and another buyer pushed for laws in Wisconsin and Iowa to limit the season and shell size.”
Ballenger, 49, employs about 130 harvesters. He exports his shells to Japan and is working with environmentalists to get state action to protect the mussels from over-harvest.
He worries about the recent influx of shellers from such states as Oklahoma, Texas, Alabama, Tennessee and Kentucky.
“We’re getting more and more shellers from out of state,” Ballenger said. “The mussel beds down south are exhausted, and they’re moving up here. States along the upper Mississippi shouldn’t sell out-of-state shelling licenses.”
Shelling is a multimillion-dollar industry in the United States, with shells alone selling for $300 to $1,000 per ton.
In 1987, 1,128 tons were collected from Illinois and 1,016 tons from Iowa. Wisconsin waters yielded 667 tons of shells in 1986, the only full year for which figures were available.
Freshwater clams and mussels are harvested by hand, using hooks on poles or by dredging riverbeds.
In Camden, Tenn., John Latendresse has branched out from simply selling shells to Japan through his Tennessee Shell Co. Now, he is growing pearls and producing jewelry--the first American to crack the Japanese-dominated industry.
He said the cultured pearl industry accounts for 3,000 jobs in Japan, and his dream is to bring as many of those as possible to the United States. But the industry may be short-lived, Latendresse said, unless state and federal lawmakers act to protect American mussel beds.
“We exported $16 million worth of mussels to Japan in 1986,” said Latendresse, citing industry research. “Cultured pearls are a $500-million-a-year industry over there. We’re exhausting our mussel beds to supply their industry. It’s a big problem, and I’m very concerned about it.”
Even representatives of Japan’s cultured pearl industry are concerned about over-harvest in the United States.
“It’s a free-for-all out there,” said Nori Sakata, president of the Sakata Pearl Co. of Tokyo, referring to the competition between shellers on American rivers. “It’s not just the Mississippi River. It’s the Ohio River and others. They definitely need restrictions.
“The commercial harvesters are over-dredging the rivers. They don’t give the mussel beds a chance for any new growth to occur. Everybody’s trying to get in on it, and they’re starting to dredge smaller rivers. It doesn’t do any good for the ecology.”
Sakata runs the Chicago office of the company, which imports jewelry and cultured pearls grown at the family oyster farm in Japan. Founded in 1956, the company began its U.S. operation 25 years ago and had $3.5 million in sales last year.
Persian Pearl Industry Dead
“I think they might need to protect their resources better,” Sakata said. “The Persian Oriental Pearl industry is dead because they didn’t protect it. The Persian Gulf used to be a hotbed for pearls.
“If people don’t protect their resources, they’re going to lose them.”
Ron Refsnider, a staff biologist for the federal Department of the Interior’s Fish and Wildlife Service in Minneapolis, said several states have laws governing mussel shells, although they are inconsistent and vary widely.
Refsnider said it is unlikely the agency will impose quotas or restrict shelling, even though 25 species of mussels are on the endangered list and 75 species are candidates.
“If anything regarding the threat to mussels is overstated, it’s the ease of solving the problem,” Refsnider said.
“Mussels are very good indicators of the biological health of an ecosystem. A lot of factors have contributed to the very serious mussel decline. It would cost millions of dollars to solve, and no one is certain as to the cause.”
Mussels Lack Charisma
Mussels don’t help their cause any, Refsnider said, because they are “not a real charismatic species.” They have largely been ignored except for their commercial value.
Mussels and their cousins, clams, long have had commercial value. American Indians collected them, ate the meat and used the shells as ornaments. Prospectors set off “pearl rushes” on mussels in the 19th Century, and in 1891 the mother-of-pearl button industry was launched using discarded shells.
Development of plastics in the 1920s killed the mother-of-pearl button industry, and mussels had relative peace until water pollution started taking its toll in the 1950s.
The spread of mussels also was restricted by construction of locks and dams as well as by declines in certain species of fish that carry embryonic mussels like hitchhikers up and down river systems.
Recent studies about mussel die-offs in American rivers over the last five years have focused on an invasion of disease-carrying Asiatic clams. No matter the cause, their loss trickles down through the ecosystem. Rivers become more polluted without nature’s filters, and wildlife that once fed on the little creatures are driven from the area in their search for food.
Sanctuaries Proposed
Proposals to save freshwater mussels and clams in the United States have ranged from federal import taxes on pearls, mussel harvest quotas, shorter shelling seasons and a ban on exporting raw shells. But the solution most exciting to Sparks is creation of river sanctuaries for endangered mussels.
Seven sites along the Illinois side of the Mississippi River have been proposed as sanctuaries, where scientists would have unrestricted access to study mussels and clams.
“Sanctuaries are urgently needed on the Mississippi River,” Sparks said. “We have several endangered species, which we must save.”
But Latendresse is not impressed with the sanctuary idea.
“Several states have created sanctuaries, but they don’t follow up with research funds to study the mussels, so the sanctuaries are worthless,” he said. “There’s so much money to be made, the shellers harvest them out of the sanctuaries.”
