Tuesday, December 26, 2017

Mussels Lure Fish

Mussel with "crawfish lure" - Chris Barnhart
Dr. Chris Barnhart's videos are featured in a National Geographic posting.  While many in the Ozarks know him from his passionate support of the Butterfly House at the Springfield Botanical Center, his day job is in research on fresh water mussels and the methods of raising them in laboratories which takes him around the globe. 

Mussels are the Rodney Dangerfield of the rivers, getting no respect.  In a word association game, if you say "mussel" the usual response is "Zebra".  If you Google mussel images, you might think that mussels live only in pots on a stove.  And in real life, don't they just lay on the stream bed and suck up water?

Consider for a minute their family history.  Unable to move great distances, how can they be found upstream after floods?  The answer is fish.  They depend upon fish to raise their babies and deliver them upstream.  Their deceptive methods to entice fish into hauling their newborn around are described in this National Geographic link.

Mussel ready to grab a fish - Chris Barnhart
While most countries have fewer than 20 mussel species, North America has 300+ species.  Our Midwest region has 78 species but more than half are endangered.  So why should we care whether they survive?
  • They require clean water and their declining numbers are a red flag warning us about the health of our streams.
  • As filter feeders, they clean up plankton and silt, then become another link in the food chain; prey for raccoons, otters, herons and occasionally fish.  
  • They are sold to Asian industries to put into oysters as the nucleus to create pearls.
  • Mussels don't get cancer. Could their secret help us prevent cancer?
Mussels were important as a food source for Native Americans as evidenced by large shell middens along the Mississippi and Ohio valleys.  The shells were used as tools, decorations and trade items, showing up at inland sites.

Around the turn of the 19th Century, mussels were a major industry on the White River in Arkansas and southern Missouri, first as pearls and then for the shells as buttons.  Elmo Ingenthron described this period in The Pearly Waters, beginning with the "1891 finding of a 14 grain fine luster, pinkish-colored pearl which sparked a virtual stampede of pearl hunters into the river."  The popularity grew as everyone "dived in" so to speak and by 1903 the market made $125,000.  Meanwhile several factories popped up along the White River, cutting button blanks to be sent for drilling elsewhere.
Crow-hooks- Stateoftheozarks

"Shellers jury-rigged lines of heavy “crow-hooks” stretched across long bars which were then trolled through the clear, cold water behind john boats. Mussel species snap shut when provoked and crow-hook trolling proved an efficient method of collection. The mussels would close on the hooks and be hoisted up. Onshore, buyers steamed the mussels and removed the innards (which were then sold as hog feed). The cleaned shells were taken by barge to local button factories. Early records suggest as many as two million pounds — and an estimated eight million of these mussels — were pulled from the White River each year." Stateoftheozarks.net