FLOOD04610

• County: Statewide
• Basin: Statewide
• Title: Overview of River-Floodplain Ecology in the Upper Mississippi River Basin
• Date: 12/9/1996
• Prepared By: USGS
• Floodplain - Doc Type: Educational/Technical/Reference Information

CHAPTER 4: ECOLOGICAL TRENDS OF SELECTED FAUNA IN THE UPPER MISSISSIPPI RIVER

43

of thousands of tons of native mussels. At about the same
time, John Boepple began exploiting mussels to produce
buttons in Muscatine, Iowa. By 1898 there were 49 but-
ton-making plants in 13 cities along the Mississippi River
(O'Hara, 1980). Thousands of people were employed in the
shell industry.
The booming button industry depended upon an end-
less supply of mussels. Mussel beds were stripped of mus-
sels without regard to size or species because there were no
harvest regulations. Carlander (1954) reported that a single
mussel bed, 2 miles long and a quarter mile wide, generated
500 tons of mussels in 1896. Another bed near New Boston,
Illinois, produced 10,000 tons of mussels (100 million indi-
viduals) in 3 years. By 1899, the decline in mussel resources
was becoming apparent. Smith (1899) reported on the
decline of mussels due to overharvest and recommended
restrictions be put in place to allow stocks to recover.
Pressure on mussel resources continued. and harvests
began declining. The decline reported by Smith was of such
concern that the U.S. Bureau of Fisheries established a bio-
logical station at Fairport, Iowa, in 1908 to investigate the
artificial propagation of mussels. Carlander (1954) cited
from a U.S. Fisheries Service Bulletin of March of 1930
that the mussel harvest in Lake Pepin declined from 3,000-
4,000 tons in 1914-1915 to only 150 tons in 1929. Between
1912 and 1914, lhere were 6,626 tons of shells harvested
from the Mississippi River and 5,890 tons from the Illinois
River (Coker, 1919). According to Coker, 55,671 tons of
mussels were processed by the button industry in 19 I 2.
Scarpino (1985) reported that, in 1916,20,000 people
were employed in the button industry and manufactured
$ I 2.5 million dollars worth of buttons, but that decreased to
about 5,000 people and $5.8 million worth of buttons in
1929. After 1930, the mussel industry began to decline even
further, due in part to a depleted source of shells and a
long-needed implementation of mussel harvest regulations.
In 1967 the last known pearl button plant near Muscatine,
Iowa, closed. In the mid-1960's, however, the industry
began a resurgence when mussel shells were found to serve
as a seed pearl in the cultured pearl industry. The harvest of
mussels from the UMR for pearl production continues
today.
Compiling accurate harvest statistics from the UMR
for the last 25 years would be difficult at best. Harvests for
commercial species, predominantly Megalonaias gigantea
(washboard) and Amblema plicara (three-ridge), fluctuated
widely for a number of reasons, such as price per pound,
institution of size limits, differences in reporting require-
ments among the Stales, and natural occurrences such as the
flood of 1993. In addition, there was a significant die-off of
mussels in the UMR during the 1980's (Neves, 1987).
Blodgett and Sparks (1987) reported that up to 33.3 percent
of mussels collected in Mississippi River Pools 14 and 15 in
a 1985 sampling effort had been dead since 1983. Because
of the die-off, relict shells have made up a major portion of

the harvest in recent years. In 1991, for example, dead
washboard shell made up 36 percent of the total harvest in
Iowa (Ackerman and DeCook, 1991).
In 1989 there were 220 licensed shellers in Wisconsin,
and washboard mussels were selling for about $0.40 per
pound. In 1990 there were 334 licensed shellers, and wash-
boards were selling for about $1.00 per pound live and
$1.50 per pound dead (Welke, 1993). By 1992 the price of
washboard (dead) had plummeted to $0.55 per pound, and
there were only I 19 licensed shellers. During 1988-1992 an
annual average of 2.5 million pounds (1,279.5 tons) was
harvested from the five UMR States of Iowa, Illinois, Wis-
consin, Missouri, and Minnesota (Welke, 1994).
The most significant factor that may affect the future
of native UMR mussel fauna is just now emerging. That
factor is the zebra mussel that was recently introduced into
the UMR watershed from the Great Lakes. The zebra mus-
sel entered the watershed in 1990. In less than 4 years, the
exotic zebra mussel has already become widely distributed
along the Mississippi and lIIinois Rivers. The Illinois Natu-
ral History Survey monitored the zebra mussels in the Illi-
nois River in 1993 and found that they were heavily
colonizing native mussel beds. Near the mouth of the illi-
nois River at Grafton, up to 99 percent ofthe native mussels
were infested (S.D. Whitney and others, unpub. data, 1993).
Investigators found freshly dead mussels so heavily infesled
they could not force the shells closed. UMR mussel biolo-
gists fear that native mussels will be devastated. or even
extirpated, before some "steady state" of coexistence is
achieved. Their concern is heightened because mussel pop-
ulations are already under stress from the factors previously
discussed, As in any biological system, components that are
already under stress are subject to potentially greater
impacts than otherwise healthy ones.
In order to draw special attention to mussel species that
are in jeopardy of extinction, extirpation, or significant
decline, the U.S. Fish and Wildlife Service and the five
UMR State natural resource agencies have each conferred a
variety of special designations for what are commonly
referred to as rare, threatened, or endangered species. Each
of the States and services has different criteria for these des-
ignations, making interpretation of a particular species' sta-
tus difficult.
Table 4-1 is a compilation derived from published lists
or resource agency data bases, specifically addressing mus-
sel species known to historically occur on the UMR main
stem. Some species that may have been present in main-
stem populations but are now extirpated may not be listed.
These unionid species could be considered those most likely
to disappear from the UMR if the ecological integrity of the
system deteriorates further.