The first known reproduction of the pallid sturgeon in the Lower Missouri
River in at least the last 50 years has been confirmed by U.S. Fish and
Wildlife Service biologists, who point to the startling discovery as
evidence that the fish, whose ancestors date to the days of the dinosaurs,
may have a better chance at recovery than previously believed.
"This remarkable news is more than just a testimony to the need to conserve
habitat in order to pull an endangered species back from the brink of
extinction," Secretary of the Interior Bruce Babbitt said. "It speaks
eloquently for the need to restore some natural flows to rivers so they're
more than just dammed and channelized flood control projects sluicing fresh
water toward the sea. When the Edwards Dam was removed from the Kennebec
River in Maine, Atlantic salmon were seen back in that stretch of river
almost immediately. When we let the Big Muddy be the Big Muddy, suddenly
on of America's historic and most endangered gamefish is spotted spawning
in nature once again."
"This is wonderful," said Steve Krentz, leader of the Pallid Sturgeon
Recovery Team in Bismarck, North Dakota. "Until these tiny sturgeon
specimens were found, the only young pallid sturgeon we have seen were
products of hatchery spawning operations."
The fish, which can attain a weight of 100 pounds, a length of 6 feet and
which have a lifespan of 60 years, have been listed as an endangered
species since 1990, indicating a concern that the species was headed for
extinction.
Aside from the sturgeon's importance as a natural inhabitant of the
Missouri and Mississippi River systems, the pallid sturgeon has economic
benefits as some anglers consider it one of America's premier gamefish.
Eventual full recovery could mean that the sturgeon would be considered for
removal from the endangered species list and would again be available to
sportfishing enthusiasts.
The sturgeon is also considered an indicator species whose abundance and
distribution are directly related to the quantity and quality of suitable
habitat and river hydrology. That these specimens were collected at a
habitat restoration project on a unit of the Big Muddy National Fish and
Wildlife Refuge indicates that efforts to put back some of the 500,000
acres of habitat lost to channelization can produce dramatic results.
Jim Milligan, project leader for the Fisheries Resources Office in
Columbia, Missouri, said the specimens were found along a restored sandbar
in a side channel of the Lower Missouri River that had been cut by the
flood of 1993 and expanded to a chute-island-sandbar complex by more
flooding in 1995 and in 1996. It is the first new habitat of its kind the
river has been allowed to create in more than 50 years.
"We acquired the land for the Refuge and gave the river some freedom to re-
create some lost habitat through natural processes of erosion, deposition
and succession," Milligan said.
"And the area became nursery habitat for juvenile pallid sturgeon. The
most significant aspect of this find is that it clearly demonstrates that
we can use the river's energy to restore habitat for the benefit of
threatened, endangered and declining fish species. More than 40 other
Missouri River fish species have also been documented using the restored
habitat."
Pallid sturgeon populations began to drop with the advent of dams, and also
when their habitat was altered from shallow, silty rivers with sand and
gravel bars to deeper clear channels favored by commercial river traffic.
The side channel where the sturgeon were found is not a part of the
navigation channel.
An adult pallid sturgeon is a rare find today in any segment of the
Missouri River system. In the early 1990s, the Service and its state
partners began a hatchery reproduction program and stocked the Missouri
River with at least 3,000 hatchery sturgeon to keep the species alive.
"We know the fish found in Missouri are not the result of our stocking
efforts," said Steve Krentz, leader of the Pallid Sturgeon Recovery Team in
Bismarck, North Dakota.
"The juvenile fish we placed in the river were 8 to 10 inches long and the
specimens collected in August were less than an inch long."
Pallid sturgeon historically inhabited rivers and tributaries in Arkansas,
Iowa, Illinois, Kansas, Kentucky, Louisiana, Missouri, Mississippi,
Montana, North and South Dakota, Nebraska and Tennessee. Some sturgeon
still inhabit some of those areas, Milligan said, but the populations are
far below what they were in the 1950s and 1960s.
The Missouri Department of Conservation lists the pallid sturgeon as
exceedingly rare and confined to the Missouri and Mississippi Rivers
penetrating only a few miles into the Mississippi upstream from the mouth
of the Missouri. The species is somewhat more abundant in the Missouri
River upstream of Iowa, but nowhere in its range is it common.
Unlike such finny freshwater companions as the trout and bass, the pallid
sturgeon is a homely specimen. It is distinguished by pale, bony plates
instead of scales, has a reptile-like body, sucker-type mouth and large
whisker-like growths that help it sense its surroundings. It is similar in
appearance to the shovelnose sturgeon but is much lighter in color, has
smaller eyes and a longer and sharper snout.
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