To the FWGNA group,
As many of you are aware, Paul Johnson (current chairman of the FMCS Gastropod
Committee) has been working for several years to artificially propagate Leptoxis
plicata, the federally endangered pleurocerid snail endemic to Alabama's
Black Warrior drainage. Earlier this week he wrote to inform us of
the successful release of almost 5,000 yearlings back to the wild.
He suggests that this may be the first release of an artificially cultured
endangered freshwater snail in the United States. I think it may be
the first anywhere in the world, ever. Congratulations, Paul!
Paul sent us an article from the Sunday edition of the Birmingham (AL) News
which offers a pretty good overview of the project and is mostly accurate.
[Paul's notations are in brackets.] We join him in thanking Paul Hartfield
of the USFWS and Stan Cook of AL-DCNR for making this small but important
step possible.
Keep the faith!
Rob
---------[Birmingham News 07/20/03]----------
At a Snail's Place
Scientists release critters to breed in Locust Fork
JERRY BAKER
News staff writer
Hoping to reverse a trend that began decades ago, research
scientists released 4,876 snails Saturday into the Locust Fork of the Black
Warrior River near Kimberly. It was the first of five annual releases planned
in hopes of restoring the population of a federally endangered species.
Though small, the plicate rocksnail is a cornerstone species upon which all
the other animals living in the river depend, said Paul Johnson, a research
scientist with the Tennessee Aquarium Research Institute. The snail lives
beneath large, flat rocks and eats algae and organic matter; it is food for
turtles and fish.
Sixty years ago, the half-inch-long snail was so plentiful
in the Locust Fork that a person standing anywhere in the river's shoals
would have a couple dozen snails under each foot, Johnson said.
Now those snails are almost gone, victims of pollution and sediment washed
into the river. Once found along the entire length of the river, their
numbers have diminished so much that they are found in only a few shoals
along a 20-mile stretch between Interstate 65 and U.S. 78, about 2 percent
of their original habitat.
Johnson and several assistants carried the snails to the
river in three one-gallon buckets in a cooler. He let the buckets sit for
a while in shallow water to adjust their water temperature, then sprinkled
the snails in an area where the water was a couple of inches deep.
The released snails are the offspring of 100 he collected from the river
in March 2002 from shoals near Sayre. Saturday's release is a result
of five years of research and development, Johnson said. "This is aimed
at trying to develop the techniques for restoring freshwater snails, especially
in the Mobile River Basin," Johnson said. The Warrior River is a part of
the Mobile River Basin.
The basin is one of the most biodiverse in the world,
Johnson said. It also is one of the most troubled. Of the 60 species of freshwater
snails that have become extinct in North America, 42 of them are from the
Mobile River Basin.
Eleven snail species are listed by the U.S. Fish and Wildlife
Service as threatened or endangered, and eight of them are from the Mobile
River Basin, he said [clarification - 11 listed species in AL only].
Sediment from development and strip mining along the rivers has washed into
the streams and covered up the snails' habitat. Pesticides and herbicides
also have contributed to snails' dwindling numbers, he said. The release
site near Kimberly was chosen because Johnson said he knows snails can survive
there. He found one snail after a couple of hours of searching a couple of
months ago but came across none in a search last week.
Johnson will visit the river several times a year to monitor
the snails. Each is marked with a one-millimeter tag affixed with dental
cement, he said. The tags help researchers monitor the progress of the snails
and ensure the same ones won't be used for breeding stock every time [clarification
- adult broodstock was tagged, not the juveniles]. This fall he will
release the 97 survivors of the original 100 he removed last year as breeding
stock. He will put those back where they came from near Sayre [error - this
was completed last year, and no adult mortality has been associated with
2003 propagation efforts].
Johnson plans to collect more each spring, and later in
the summer he will release more. Johnson hopes to improve his technique so
that about 10,000 1-and 2-year-old snails will be released each summer.
With conditions along the river improving, Johnson hopes
his repopulation efforts will give the snail the boost it needs to survive.
"They can take themselves out from the brink of extinction," Johnson said.
"We've just got to give them a chance."
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