USA: pallid sturgeon in danger


In this video:

U.S. Fish and Wildlife Service biologist Andy Plauck explains the plight of the Pallid Sturgeon and what is being done to save this endangered species.

From the Omaha World-Herald in the USA, about this species in danger:

Jurassic-Era Fish on Its Last fin

A Dinosaur of the Depths Faces Extinction Unless Missouri River Changes Are Made.

Publication date: 2005-11-13

ON THE MISSOURI RIVER — Wildlife biologists use the term “charismatic megafauna” to describe animals such as pandas, kangaroos and whales, popular creatures that elicit public concern and support.

The pallid sturgeon will never fall into that class of critters.

It’s a fish, for starters, and an ugly one at that.

With its pale color, bony scales and flat, spadelike head, the pallid is enough to make a channel catfish seem like Julia Roberts.

Herb Bollig of the U.S. Fish and Wildlife Service acknowledges that the pallid seems a creature that only a fisheries biologist could love.

But he thinks the public would love the fish, too, if it got to know this ancient mariner of the Missouri.

Here is a marvel that was so perfectly adapted to its environment it has swum the Missouri River’s muddy waters since the time of dinosaurs.

With a keen sense for movement and a Hoover-like mouth, the old behemoth has trolled the murky river bottoms, sucking up aquatic insects and small fish.

“They’re so ugly, they’re beautiful,” Bollig said.

“They’ve been around so long, they’re like a living dinosaur. It would be sad if they were to disappear.”

Despite its long history, the pallid sturgeon swims today at the brink of extinction.

The Jurassic-era fish is rarely caught in the wild, even when biologists sweep the Missouri bottom looking for it.

When fish are found, they are almost always 30, 40, even 50 years old — a sign the pallid long ago stopped reproducing in the wild.

Pallids raised in hatcheries as a stopgap are the only young fish on the river today.

Scientists say the only way to ensure the pallid’s survival is to return the river to a more natural state, more as it was before it was dammed, straightened and walled in by man.

The shovelnose are not endangered, but their relatives, the pallid sturgeon, are. Because a young pallid can be mistaken for a shovelnose, the U.S. Fish and Wildlife Service recently proposed declaring the shovelnose a threatened species in areas where the two types overlap, giving it regulatory authority: here.

The discovery of two lab-confirmed tiny pallid sturgeons in the Missouri River near St. Louis offers fresh proof the endangered species descending from the dinosaur era is reproducing, the Army Corps of Engineers said Tuesday: here.

Big gulf sturgeon caught: here.

Shortnose sturgeon: here.

There are far more species in danger in the USA:

SACRAMENTO, Calif. Nov 15, 2005 — More than 800 animal species in California are imperiled by development, pollution and recreational activities, a sobering assessment that should guide development throughout the nation’s most populous state, according to a two-year government study.

6 thoughts on “USA: pallid sturgeon in danger

  1. Tue Aug 8, 3:50 PM

    The population of B.C.’s largest freshwater fish – the endangered white sturgeon – has declined by more than a fifth over the past two years in the Lower Fraser River, researchers say.

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    The white sturgeon are prehistoric survivors, dating back to the time of the dinosaurs about 200 million years ago. They can live about 100 years and grow up to six metres in length.

    In British Columbia, they were almost fished out a century ago, but their numbers have grown since then until 2004, when more than 60,000 white sturgeon were swimming between Chilliwack and the mouth of the Fraser.

    But then the trend was reversed. Craig Orr of Watershed Watch Salmon Society said the same waterways now contain about 49,000 white sturgeon.

    “That’s a decline of 21 per cent over the last two years, which is quite troubling because there had been a bit of an increase in recent years.”

    Orr says the decline is happening among smaller juvenile sturgeon that are small and spiny – because they are prickly enough to get caught up in salmon fishermen’s nets.

    “They seem to be vulnerable especially for nets set for salmon. That seems to be where a lot of the mortality is, but it’s not entirely related to that,” he said.

    “There is also a lower growth rate, probably an indication of poor ecosystem health.” Sturgeon are the world’s longest living fish.

    Most of the sturgeon caught and released these days are 90 to 120 centimetres in length, with big ones up 270 centimetres long.

    Orr said that 100 years ago, before it was overfished, the river contained monster sturgeons up to six metres long.

    cbc.ca

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  2. Posted February 21, 2007

    Sturgeon was carrying nearly 55 pounds of eggs

    For The Reporter

    A 158-pound sturgeon listed as the eighth largest on record taken from Lake Winnebago was carrying more than 54 pounds of eggs and would have spawned this year, according to a report by the Wisconsin Department of Natural Resources.

    Bill Nelson speared the fish Monday and allowed the DNR to take a look at the fish Monday night.

    The 74-inch female hasn’t been aged yet but is likely more than 50 or 60 years old.

    It was in a “black egg stage of egg development, meaning it would have spawned this year in 2007,” according to Ron Bruch of the DNR. “The total weight of both ovaries was 54.8 pounds (34.7 percent of the fish’s body weight) — in other words, the fish was carrying 54.8 pounds or an estimated 1,273,000 eggs.”

    The stomach contents will be examined by Dr. Anindo Choudhury of St. Norbert’s College in DePere, an expert on sturgeon parasites.

    Thirty-four sturgeon were speared Wednesday on Lake Winnebago, bringing the season total to 1,232. A harvest of 53 more adult females will trip the 90 percent season closure trigger. Maximum season length is 16 days, or Sunday, Feb. 25.

    What do sturgeon eat?

    Sturgeon in general are often thought of as scavengers or “bottom feeders”, but in fact, while they will eat a wide range of food items from insects to fish, they are somewhat particular about what foods they most often consume, according to Bruch.

    Lake sturgeon in the Winnebago System are very dependent upon the larvae of the infamous lake flies for much of their diet. The “red worm,” as it is known by sturgeon spearers, inhabits the deep soft “mud” areas that make up the bottom of the vast majority of Lake Winnebago, and hatches into the adult form that leave the lake in huge swarms each May to breed along shorelines much to the chagrin of lakeshore property owners.

    One of the few positive characteristics (at least to lakeshore home owners) of this large cousin to the mosquito is that it doesn’t bite.

    Studies have shown that lake sturgeon in the Winnebago System get up to 65 percent of their annual nutrition from the consumption of lakefly larvae. They get another 25 percent from another bottom insect known as a sowbug, and much of the remaining 10 percent from consuming fish — primarily gizzard shad.

    Gizzard shad is one of the sturgeon’s favorite food items in the winter months due to easy availability of a high abundance of dead and dying shad that litter the bottom of Lake Winnebago in most winters caused by a natural winter die-off.

    Lake sturgeon will also eat a wide range of other food items including zebra mussels, clams, snails, crayfish, other bottom dwelling insects and fish. They (especially the males) will also consume their own eggs on the spawning areas.

    This activity may actually be beneficial though to sturgeon production by keeping the surface of spawning sites clean so eggs incubating in the interstitial spaces of the spawning rocks have adequate water flow and oxygen to survive and hatch.

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  3. Jun 27, 7:16 PM EDT

    Rare sturgeon spawning seen in S. Dakota

    SIOUX FALLS, S.D. (AP) — Scientists have documented natural spawning by the endangered pallid sturgeon in the Missouri River.

    They had suspected the six dams in the Dakotas and Montana kept the fish from spawning by altering flow, temperature and sediment content.

    But starting in March, they found successful spawning for the first time by closely following two female sturgeon between Vermillion and Blair, Neb.

    Using radio tags implanted in March, scientists from several agencies followed the sturgeon upstream. When the sturgeon were recaptured in May, both had released their eggs in an apparent attempt to spawn, said Craig Fleming, of the U.S. Army Corps of Engineers near Yankton.

    “This is the first direct evidence that pallid sturgeon do spawn” in the section of the river between Omaha, Neb., and Vermillion, Craig said. However, “we haven’t actually answered anything other than, OK, we verified spawning.”

    The research is part of a larger attempt to recover the pallid sturgeon species.

    Another part of that effort came in May 2006, when the corps released extra water from Gavins Point Dam near Yankton in a “spring pulse” meant to mimic a natural rise and thought to cue sturgeon reproduction.

    There was no artificial rise this year, but at least two pallids spawned anyway.

    “It is encouraging to know that they are spawning, but what it ultimately means to species recovery, we don’t know,” said Darin Simpkins, a fish biologist for the U.S. Geological Survey in Columbia, Mo.

    It will take several years for research to generate recommendations for changes in river management, said Wayne Nelson-Stastny, of the U.S. Fish and Wildlife Service.

    “We went through more than a century of changes,” Nelson-Stastny said. “I think people’s expectation in today’s world is for instant results, but you’ve got to think about where we’ve been with this river.”

    Information from: Argus Leader, http://www.argusleader.com

    © 2007 The Associated Press.

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