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The Mississippi is one of the greatest rivers in the world. Drainage
of this river and its tributaries embraces nearly one-third of the land
surface of the United States. It is more than 4,000 miles in length from
the headwaters of the Missouri River tributary to its confluence with the
Gulf of Mexico.
The river was discovered by DeSoto in l54l. Marquette and Joliet were
the second white men to see the Mississippi when they reached the mouth
of the Wisconsin River in l673. These voyagers were warned by the Indians
before going onto the river that it was inhabited by demons and giant fish
that would most certainly destroy them.
Mark Twain believed Indian traditions were based on the presence of
giant sturgeon, paddlefish and catfish. In "Life on the Mississippi,"
he wrote of having seen monstrous-sized catfish "six feet long, weighing
250 pounds." Even today, traditions and myths survive among river
people of giant fishes and other river creatures of fabulous size.
When white men first visited Iowa, the Mississippi was a major source
of food for the native Indians. The great burial mounds along the Mississippi
River contain evidence that prehistoric tribes depended greatly on this
"Father of Waters" for stable food supplies of both freshwater
mussels and fishes.
The Mississippi River borders Iowa for more than 300 miles, entering
the state between precipitous bluffs that rise four to six hundred feet
above the river level. Bluffs diminish in size and spectacular appearance
from Bellevue southward. The river meanders east and west through numerous
side channels, chutes, and sloughs across its two- to six-mile wide valley.
From north to south along our entire border, the river becomes systematically
wider -- but shallower. The river bed is primarily sand and mud, with few
bedrock outcroppings, the most notable of which are the Chain-of-Rocks
at LeClaire and Dubuque and the falls just above the mouth of the Des Moines
River.
Waters of the Mississippi become muddy during flood conditions. Much
of the time, however, it is quite clear, this being particularly true in
late summer, autumn and winter. Our part of the river flows about two miles
per hour during normal water stages, although current speeds of up to five
miles per hour are common during high water periods.
The Mississippi River in its original appearance consisted of a seemingly
unending series of pools separated by shoals, bars and rapids, with a channel
or series of channels between -- much like our larger interior streams
today. These channels were obstructed by rocks and snags which, during
low water levels, separated into many side channels of narrow width and
little depth until the stream took on a "braided" appearance.
Initial
engineering on the Mississippi River occurred in l824 when Congress authorized
improvement for navigation by the removal of snags and other channel obstructions.
As early as l836, improvements were carried on by removal of snags and
steamboat wrecks from the rapids at Keokuk and Rock Island. Shortly after
this date, a canal and locks were constructed in the river at Keokuk. In
l905, an act of Congress permitted construction of the Keokuk power dam.
An act two years later authorized provisions of a six-foot channel for
navigation from the Missouri River to Minneapolis by "construction
works, dredging, diking, canals and locks." In l935, additional legislation
was approved which authorized a nine-foot channel over the same river reach
by means of locks and dams supplemented by dredging. The present dams now
controlling the river resulted from this act. Engineering and environmental
studies are currently being conducted to ascertain the feasibility of a
twelve-foot navigation channel with year-long navigation.
Eleven permanent channel dams affect the river bordering Iowa, starting
with Lock and Dam No. 9 at Lynxville to Lock and Dam No. l9 at Keokuk.
Other Iowa dams are located at: No. l0, Guttenberg; No. ll, Dubuque; No.
l2, Bellevue; No. l3, Clinton; No. l4, LeClaire; No. l5, Quad-Cities; No.
l6, Muscatine; No. l7, New Boston; and No. l8, Burlington.
The river was originally inhabited by unbelievable numbers of clams
(freshwater mussels) of various kinds. This abundance of clams was responsible
for the establishment of a huge pearl button industry, the largest in the
world, centered at Muscatine. Prior to dam construction, millions of tons
of shells were taken, but since the nine-foot channel was established,
suitable habitat for mollusks has largely disappeared under heavy deposits
of silt, and the remaining button industry is supported primarily from
man-made materials. By the early l930`s, commercial clamming had virtually
disappeared along the Mississippi.
Development and use of prepared clam shell pieces in the culture of
pearls revived clamming in the mid-l970`s, but clam harvest was nowhere
near that at the turn of this century. The reported catch of clammers licensed
in Iowa waters of the Mississippi in l976 was less than 300 tons, which
held stable into the l980`s. Most of this harvest was exported to the Orient
for the seeding of pearl clams in the culture of these valuable jewels.
From an infant industry in the early river settlements, commercial fishing
grew as the population in the midwest increased. Rapid transportation facilities
and refrigeration, plus the introduction and establishment of carp in the
l880`s, put commercial fishing on the Mississippi River into a "big
time" class. Commercial food-fish catches from the river provide a
large proportion of the freshwater fish species consumed in the midwest
and along the east coast today. Value of the fishery in Iowa exceeds well
over one million dollars each year.
The fishing industry on the Mississippi supports wholly or, in part,
many families. Over the past forty years, the annual catch of fish has
not changed a great deal. The average commercial fish harvest for the five-year
period l943-48 was about three million pounds, the catch being made up
of 47 percent carp, 22 percent buffalo, l5 percent catfish, l0 percent
drum, and 6 percent other species. During the thirteen-year period l970-82,
total catch was slightly over 3.l million pounds each year. Species composition
was 34 percent carp, 27 percent buffalo, l7 percent catfish, l5 percent
drum, and 7 percent miscellaneous species. The most dramatic change has
been the number of commercial fishermen licensed. Prior to l970, seldom
were there more than 400 licenses purchased. But in the mid-70`s, that
number increased systematically until by l983 over 2,250 Iowans were licensed
to commercial fish -- most in the Mississippi River. Over the years, the
number of full-time commercial fishermen has declined to only a few, while
the number of part-time operators has increased dramatically.
Most of the commercial fish species are taken with nets and seines,
although large numbers of catfish are caught on trotlines both in the river
channel and in the backwaters and chutes. Commercial fishing is strictly
regulated, with fishermen being required to license all gear and equipment
and report the number and kinds of fish taken. Catfish populations, which
are intensively fished, are protected from overharvest by a l5-inch minimum
length limit. Prior to channelization of the Mississippi River, angling
was undoubtedly much the same as that carried out in the larger interior
Iowa streams at the present time.
With
construction of the six-foot navigation channel in l907, large numbers
of wing dams and channel training structures jutting out from the shore
into the current to deepen the channel were built. This profoundly changed
earlier angling activities. Considerable fishing was done on the wing dams,
where large numbers of crappie, northern pike, walleye, and smallmouth
bass were taken. The wing dams, along with extensive shoreline riprapping,
provided lush feeding grounds for fish, and they had a tendency to congregate
in the areas where small forage fish found food and shelter. The six-foot
channel probably had very little effect on fishing in the rapid chutes
between the numerous islands in the Mississippi. Here, too, large congregations
of foraging game fish were the source of excellent fishing.
With establishment of the nine-foot channel dams, most of the wing dams
were submerged. Also, most of the rapid chutes between islands and even
the islands themselves were inundated by backwaters, forever destroying
many of the formerly productive game fishing grounds.
With the navigation locks and dams creating a series of lake-type pools
in the river, there was a decided change in the make-up of fish populations.
Fast-flowing water fish species, such as smallmouth bass, declined in abundance,
and fishes that preferred more pond-like habitat, such as crappie, bluegill,
walleye, carp and freshwater drum increased in abundance. The new channel
dams also changed favorite locations for fishing.
Best
fishing for species such as walleye, sauger, and paddlefish is directly
in the tailrace of the navigation dams, especially in late spring and autumn.
The popularity of fishing below the dams is accounted for by several basic
factors that influence fish behavior. In the first place, for the large
part of each year, the dams represent a physical barrier to fish movement
-- mostly in the upstream direction. For some distance below each stucture,
the bottom is scoured into a series of deep holes containing diverse fish
habitats, giving a particularly favorable bottom environment with highly
oxygenated water. These conditions afford excellent environment for forage
fishes and other forms of fish food. Predacious sport fishes concentrate
in these havens of easy feeding. Most of the dams are easily accessible
for fishing either from the shoreline or by boat. Boat ramps and parking
facilities are located within a short distance of all Mississippi locks
and dams. There are a total of 58 launching facilities on the Iowa side
of the river. Public lands usually stretch a considerable distance downstream
and are open to fishing. Some restrictions for safety are in effect at
all dams and must be obeyed.
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