WPSU

Wednesday, October 13, 2010

American Pearl

Floats support metal baskets full of mussels
The October 10th installment of the SlowBoat "What IS It?" quiz showed what look like skinny little logs, floating in neat rows on the water.  We had some highly creative guesses, and the envelope, please . . . . The winner is Doug, who correctly identified this scene as a freshwater pearl farm.  (Honorable mention to Phil Mac and Cindy Mitchell, who were on the right track). Doug, send your snailmail address to slowboat@emailias.com to claim your prize, an honest-to-gum tacky postcard.



Did you know there are pearl farms in America?  The farm pictured in the "What IS It?" quiz is the famous establishment at Birdsong, the marina, "resort," and all-around Tennessee tourist destination where SlowBoat docked last Thursday and spent close to a week.  I say the place is famous, because it is.  This farm was established by John Latendresse, the first person to figure out how to culture freshwater pearls in the United States. (Before that, culturing freshwater pearls was the exclusive provenance of Japan.)  Latendresse got quite a publicity buzz for his accomplishment, with stories in National Geographic and Smithsonian and network TV interviews. 

How does pearl farming work?  Earlier last week, as we meandered along the river, dodging bass boats, we noticed other small motorboats at anchor, displaying the red flag with the white stripe that means "diver down."  The Cap'n theorized these were state wildlife agency workers, repairing the underwater structures installed to attract fish.  But in fact, these divers were grubbing in the mud for freshwater mussels, which they take alive.

Some mussel divers use scuba gear. But many carry a compressor in the boat to supply them with air at the bottom.  Here's a mussel diver's boat at Birdsong Marina, cluttered with the tools of the trade.  Divers must have a "commercial mussel harvester" license to take mussels. (Illegal poaching is a problem). Back at the farm, specially skilled workers open the shells to "implant" a "nucleus," a bit of shell around which a pearl will form.  Implanted mussels then get placed in small metal cages. (They look a bit like the wire baskets you use to broil veggies or shrimp on your backyard grill!) Then the cages are suspended from the rows of floats.  These are usually plastic, like the ones you saw in the "What IS It?" picture.  Wait a year or three, open up the mussel, and there's your pearl!

A mussel diver's boat at the Tennessee Pearl Museum.  Perched on the nearest gunwale is a wooden float, and
suspended from the float are lines with metal hooks from which mussel cages can be suspended.
Local pearl farming is a small part of the contribution that mussels make to the local economy.  Divers also take mussels and process them to send the shells to Japan. In fact mussels from the Tennessee River are the main source of nuclei for all cultured pearls worldwide. We're talking multi-million dollar business here--and significant jobs in the state.  Divers bring their mussels to processing facilities where they are steamed, tumbled to extract the meat (which goes to make animal feed), and then processed into little round marbles of various sizes.

The mussel species harvested around here have picturesque names:  River pigtoe, elephant ear, monkeyface, and pink heelsplitter  (sharp shell, painful to step on!) The most common is the washboard mussel (see photo at right), which has a heavily ribbed shell.  Some freshwater mussels grow to the size of a salad plate and weigh as much as 7 pounds. A half-shell looks much like an abalone, right down to the beautiful, iridescent, pearly coating inside the shell.                                                                              Even before the invention of freshwater pearl farming, mussels were the focus of a "gold rush" in this region. That was back in the early 1800s. People collected mussels for the valuable  wild pearls they contained.  Then, in the late 1800s and early 1900s, mussels were harvested for ANOTHER use--to make mother-of-pearl buttons.  It sounds like  small thing, but it was big business--remember, this was before plastic was invented.  To give you an idea of the economic impact, in 1899 there were 60 button factories in the Mississippi River Valley employing thousands of workers--an industry valued at 23 million dollars.

You may not particularly notice them when you are out on the river. But besides their value as a source of pearls, mussels have value in an ecosystem. They are filter feeders, which means they're the clean-up crew. Quickly and efficiently, they remove tiny suspended particles from the water. Mussels are also an important source of food for many wild animals. And finally, although they're tougher than the mussels you order steamed (with frites) at a bistro, mussels were once a popular and important food for some Native Americans.

Managing freshwater mussel populations is a challenge for the Tennessee Wildlife Resources Agency. Historically the state was home to about 130 different species of mussels. To put that in perspective, consider a far more popular and conspicuous class of wildlife, birds;  Tennessee is home to a breeding bird population of just 170 species.  My point is, 130 mussel species is a genuine plethora of mussels.  

But then rivers were stripped clean in the search for pearls . . . and then came dams, changing water flow and water temperature; and farming, with the associated runoff of fertilizers and pesticides; and siltation from land development.  Today 43 species of mussels in the state are on the FEDERAL endangered species list.  And about a dozen are already extinct.  

No comments:

Post a Comment