WILLISTON, N.D. — A bison skull and a car’s transmission are two of the strangest things Ryan Wilson has pulled up in a drift net from the bottom of the Yellowstone River while trying to capture wild pallid sturgeon.
“I would not want to see the river bottom here,” said Wilson, a biological technician for the U.S. Fish and Wildlife Service. “Imagine the number of trees on the bottom.”
Wilson has been casting and pulling up nets on the Yellowstone and Missouri rivers in search of pallid sturgeon for 13 years as part of a federal program to capture adult fish for spawning, as well as to learn their habits. The eggs from captured fish are raised in hatcheries with the young released back into the rivers to ensure the endangered species does not die out.
“They’re a tough fish,” Wilson said in admiration of a species whose ancestors date back 70 million years in the fossil record. “Last year two girls swam from here up above Wolf Point (on the Missouri River), then swam down here and spawned. It was a 300-mile roundtrip in three days.”
The pallid sturgeon netters’ “office” is gray as the day begins, thanks to high clouds that resemble the ribs of a downy beast. The cottonwoods that crowd the high sandy banks of the Yellowstone River are still naked, just beginning to leaf out after the extended cold winter. Jagged white scars mar the trunks of some, while smaller trees are plowed flat, evidence of the winter’s destructive ice jams that tore across the landscape like slow-moving bulldozers. As the high water gnaws at the sandy banks, large chunks of earth continually slough off like little glaciers calving, splashing loudly into the river. The muddied water gives the air an earthy, musty scent like a just-cultivated garden.
For the netting crews, their four days on the water began each morning last week at about 8 at the confluence boat launch, just below where the Missouri and Yellowstone rivers meet below badland hills in western North Dakota. From there, the USFWS and Montana Department of Fish Wildlife and Parks teams jet-boat upstream in a search for pallid sturgeon before they spawn. The early May weather is fickle. One day it’s snowing, windy and cold. The next day the sun peeks out, the wind is uncharacteristically calm, and it’s practically balmy.
“You never know what you’re going to find on the river,” said Tyler Berger, a USFWS technician.
Tools of the trade
The crews’ tools are fairly basic. The nets are 150 feet long and 6 feet deep with leaded line along the bottom to help the nets remain upright. The two-man netting crews split duties. One drives the aluminum jet boat close to shore where the other, standing in the bow, throws out a buoy to which the net is attached. Then the driver backs the boat away from shore as the net spools out, trying to keep the net straight away from the boat.
For about 10 minutes the boat and net drift downstream, the boat driver occasionally starting up the engine
and repositioning the boat to keep the drifting net stretched out.
Where the pallid sturgeon are hiding on the brooding, broad brown river is hard to say. The joke is that some have been captured so many times that when they hear the boats coming they flee.
“They try to avoid the strong currents,” Wilson said.
Studies have shown the fish traversing from side to side as they work their way upstream, he said, using dunes along the river bottom to swim behind, blocking the stronger current. For the netters, those same dunes pose problems, giving the fish a place to hide.
Even when a radio-tagged fish is located, crews can drift and drift over the fish time after time and still not catch it. That can be frustrating.
“You can be right over the top of them and drift net after net and still not catch them,” said Everett Nelson, a USFWS technician, shaking his head in disbelief.
“It’s kind of just a needle in a haystack,” he added while maneuvering the jet boat. “They don’t like to go in real deep water, under 4 feet is what I like to look for, and stay away from where the water is really ripping and snags.”
At the same time of year when the crews are trying to net pallid sturgeon, paddlefish are also swimming upstream from Lake Sakakawea in North Dakota to spawn in the Missouri and Yellowstone rivers. They are a big fish, some weighing 100 pounds or more. They get their names from their long, paddle-shaped snouts, called rostrums. Unfortunately, they seem to be caught in the drift nets more often than pallid sturgeon and are much more unruly, thrashing their muscular gray girth to get free as the men struggle to untangle the net. Once freed, each paddlefish is carefully released. It’s even better when they somehow free themselves.
“Some days you get five or six and your like, that’s enough,” Wilson said. “They are a very strong fish.”
It’s no wonder the crew catches more paddlefish, there are more of them. The North Dakota Game and Fish Department estimates there are about 50,000 paddlefish in the Missouri and Yellowstone rivers above Sakakawea. That’s down from an estimated 100,000 in the late 1970s. In comparison, there are only about 100 adult pallid sturgeon in the rivers. North Dakota and Montana still have snagging seasons for the plankton-eating paddlefish, cutting off the harvest at 1,000 fish a year in each state. Pallid sturgeon, if caught by anglers, must be released.
Luck be a lady
Last Thursday there seemed to be plenty of big paddlefish finding their way into the USFWS nets, but no pallid sturgeon. Then Wilson received a phone call from one of the FWP crews that was netting farther upstream. They had caught a female pallid and were boating it downstream so that a blood and egg sample could be drawn to see how close the fish was to spawning.
The 38-pound female was subdued as it nosed around in the galvanized tank’s muddy river water. The fish had a brassy colored back while its stomach was pure white. Two large whisker-like barbels extended from its mouth, located on the bottom of its head. Tiny eyes probably see little in the murky waters the fish inhabits. Ridges that were rough scutes when it was younger have been worn smooth on the fish that’s probably more than 60 years old. The sturgeon’s body narrows considerably just before the tall, upright tail fin. Her nose is long, broad and relatively flat, nearly coming to a point like a large arrowhead. Everything about her body seems streamlined to ease through the current in this rugged river.
“She doesn’t have a long history of being in our hands,” said Dave Fuller, an FWP fisheries technician who has been working on the pallid project since 1996.
By scanning a microchip planted in her skin, they discover that she got her radio tag in 2004. In 2006 she was taken to the Garrison Dam National Fish Hatchery to be spawned. About 500 of her progeny were stocked on the Missouri River at Fred Robinson Bridge, above Fort Peck Reservoir. Twenty-nine of her offspring have been captured since then.
“So it seems her progeny here will carry on,” Fuller said.
That, after all, is what these long, often cold days on the Yellowstone River are all about for the netting crews – ensuring the survival of an endangered fish. And even though there are fewer adult pallid sturgeon every year as the fish die, the crews will keep on netting in hopes of finding one that has somehow eluded them all these years.
So the netting teams, like fishermen, are always hopeful when they motor out onto the water in the morning. They are hoping that they won’t snag trees or pull up an auto transmission in the net, instead finding a new pallid sturgeon so that its genetics can be ensured in this rugged watery ecosystem.