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titled Survivors from the Dinosaur Age by Hannah Nordhaus. For one hundred sixty two million years, sturgeons have fended off everything they have ever faced, until humans push them to the brink of extinction. Inside the urgent flight to fight to protect the last of these living fossils, the river

flows vast and soundless. It's December and southern Kazakhistan, and the landscape near the Sir Darya River is smudged in shades of brown and toupe, dormant grasses, silted floodplains, leafless trees. This is not the most picturesque stretch of river bank, strewn as it is with food wrappers, bottles, and decomposing sedan. Overhead, the sun is obscured by a haze of coal and wood smoke. But when it comes to what Berney. Cahooja

is searching for the spot feels perfect. This is the habitat we need, says Cahuja, an aquatic conservation biologist with the Tennessee Aquarium Conservation Institute. He's hoping to find a species of sturgeon, the sir Daria, that's native to these waters but hasn't been seen since the nineteen sixties after a series of Soviet dams were built throughout the river system.

Those projects blocked access to the fish's spawning grounds, and fewer changed forever change the flow of the sir Dharia, which drains from the high peaks of Kyrgyzstan into what is now the remnants of the Aral Sea. If the sturgeon somehow still Existskohuja thinks this silty, shallow expanse of

river is where it can be found. Some months earlier, khojaen contact had been contacted by the conservation organization REWILD, which administers a program to search for what it calls lost species creatures that haven't been seen for at least a decade and could be extinct, but there's not enough data to be conclusive. The officials at REWILD reached out to Kooja, knowing that he was one of a very small collection of scientists who have ever laid eyes on

the Sir Darja star sturgeon. As a graduate student in the nineteen nineties, he visited museums in London, Moscow and Saint Petersburg and videotaped twenty seven spindled specimens bleached away from years of storage. They said, you're the expert, Cahuja said, remembering the call with rewild, and I said, well, I've seen them dead in a jar. The circuit Darya sturgeon is a distinctive looking fish, and, at a maximum length of roughly nine inches, is the smallest of the twenty

six species of sturgeons. The largest is the Beluga, the biggest ever recorded, pulled from the Volga River in eighteen twenty seven, measuring more than twenty three feet and weighing over thirty two hundred pounds. All sturgeons have a long, flat snout, dangling whisker like barbeles that detect bottom dwelling prey, and five lines of horny bony scouts that climb vertically up the length of their bodies. It's hard to mistake

this ancient fish for anything else. Cross a catfish, a shark, a stegosaurus, and a pruning saw, and you're not far from imagining a sturgeon. For one hundred sixty two million years, they lived through climate swings, continental shifts, volcanic eruptions, and a mass extinction. They survived the asteroid that killed the dinosaurs. Everything that nature and space could throw at them, says Cahoja, everything except humanity. Today, they are most the most endangered

group of fish in the world. Since nineteen seventy, global sturgeon populations have dropped a catastrophic ninety four percent. The International Union for Conservation of Nature IUCN lists twenty five sturgeon species as vulnerable or endangered, seventeen critically so, and one species is extinct in the wild. Three of the critically endangered species, including the sir Daria, are feared extinct as well. Ecologically, sturgeons are on the brink. Economically, they

are some of the most valuable animals on Earth. Much of the sturgeons decline can be attributed to overfishing. Caviare the fish profuse Obsidian eggs is salted and sold across the globe as an edible symbol of status and wealth. Some tins surpass six hundred dollars an ounce, But even for species like the sir Daria that aren't sought for their row, human made decisions and environmental changes have been devastating. It took only two hundred years for humans to destroy

every riverine habitat where sturgeons live. Cahoja says. Sturgeons evolved over one hundred and sixty million years ago in free flowing rivers places without barriers. All sturgeons migrate, says Cahooja, there are now simply too many things in their way. Dams, reservoirs, dredging and irrigation diversions block migration to spawning grounds upstream,

and strand larvae floating downstream. Runoff from agriculture can create toxic algal blooms, while development, logging and mining destroys spawning habitat and produce harmful sediments. Gohujah hopes some small number of sier Dharia sturgeons have survived this age of man. If the fish could be found, Cahoja will follow a now well worn playbook, capture a breeding population of males and females, set them up in a hatchery, and raise

them for reintroduction into the wild. Where there are dams blocking spawning roots, there are now hatchery and transport programs. Where the overfishing, there are now laws and institutions banning or limiting unsustainable harvest. Even the caviat industry is now playing a role in bringing sturgeons back back from the brink. Before arriving at the river, Khusha had stopped at a roadside fishmonger's stand and passed around printed photo of those

museum specimens. Trucks groaned past on the highway as a fisherman studied the picture and then confirmed that he had pulled something similar out of the water a few years back, which made Khusha even more excited to get into the river. Making their way toward the water, Khushaan as colleague Dave Neelie Kirrie a custom sown net they will use to sweep the river. Three Kazakh fisheries officials have driven down from the Aral Sea in a big Soviet era truck

to supervise the efforts to find the lost fish. One of them, tinspik barak Baya, leans against the old vehicle, watching as Kahusha and Neely wade into the river. We have a chance, he says. With this chance very small, we can hope. It's April and Wisconsins Wolf River is

teeming with sturgeons. The fish prowl the rocks near the banks, their fins breaching the water in the frothing spillway of Shawano Dam, which lies between a paper mill on one side of the river and the town of Shauano's Sturgeon Park, a tiered greenway at the river's edge. Since the barrier's construction in eighteen ninety two, this is marked the farthest

point up the river where the sturgeons can swim. A crowd is beginning to gather along the banks to watch this annual rite of spring, in which thousands of sturgeons swim from Lake Wobegon one hundred twenty five miles downstream to spawn. These fish are a small number of the roughly forty thousand adult sturgeons in the Lake wobe Winnebago system. Wisconsin statewide lake sturgeon population is one of the healthiest on the planet. Theirs is a comeback story that sturgeon

advocates are seeking to emulate around the world. Sturgeons were once so abundant in North American rivers that, according to indigenous lore, you could walk across the river on the fish's backs. Lake sturgeons, the fish that are spawning below Shawano Dam and top out around seven feet, once ranged from the Great Lakes and Hudson Bay south to the Mississippi Watershed, but by the nineteen seventies they had been

largely wiped out of many of their native rivers. In Wisconsin, sturgeon populations had plunged years earlier, but foresighted management averted disaster. In nineteen fifteen, the state banned all fishing for lake sturgeons for a time, then carefully tinkeered with catch and size requirements that are still in place. Those catch limits are set by Margaret Statig, the states so called Sturgeon General, a moniker that tends to stick to all sturgeon bosses.

State ag is a fisheries biologist with the Wisconsin Department of Natural Resources charged with overseeing the health of the Lake Winnebago population. She also collaborates with the federal government on a breeding program meant to restore lakes sturgeon numbers across their former range. This is her first spawning season her predecessor pleaded no contest to misdemeanor charges of theft of caviare and as she stands along the Wolf River watching the sturgeons prepare to spawn, she points to a

female moving slowly along the rocks, bloated with eggs. She looks like a goodyear blimp, Estatic says, noting that the males are thinner and sleeker, more like torpedoes. They're more active, too, jumping out of the water from time to time, their bodies vibrating like plucked guitar strings. When a female sturgeon is ready to spawn, a group of males surrounds her, thumping her abdomen with their tails so vigorously that an onloquor perched on the river bank can feel the rocks

shake until she extrudes her eggs. Thousands at a time. The eggs and milt fish sperm meet and saddle on the rocks or gravel at the bottom of the river, hatching as larvae a week later to ride the spring runoff back down the river. They vibrate when they spawn, Static says, referring to what the locals call sturgeon thunder. Once the thunder begins, Static's team, which is here to count and characterize the fish, also gets biddy busy netting

the sturgeons and laying them on a tarp. One team member holds a fish's head, another the tail, while a third scans for telemetric tags that indicate whether the fish has been caught before. Static will set the next year's fishing harvest caps using an algorithm based on numbers of tagged and untagged fish. Thanks to these quotas, the Wolf River sturgeons are now healthy enough to sustain their own numbers. Federal officials hope to build on that success by breeding

Wolf River sturgeons to restock rivers in other states. After each fish is measured, sexed, and tagged, it is handed off to group from the U. S Fish and Wildlife Service, which collects eggs and milt from the female and male sturgeons, mixes them together with a turkey feather it's soft enough to not damage the eggs as they are stirred, then transports the fertilized eggs back to the Warm Springs National

Fish Hatchery and Georgia About a month later. Grow out facilities like the Tennessee Aquarium where Cahoja works pick up the fish and raise them in tanks, feeding them a diet of brine, shrimp and blood worms. After the fish have grown six inches long, they are released into rivers where sturgeons were long ago wiped out by overfishing, dredging, pollution,

and dams. Since two thousand, the aquarium and its partners have reintroduced more than three hundred thousand lake sturgeons into the Tennessee and Cumberland rivers, hoping they will thrive in

the stretches between dams. The first females are just now reaching reproductive age somewhere north of twenty years in lake sturgeons, though Cahooja and his team have yet to see evidence that the reintroduced fish have successfully spawned and the larvae have survived the perilous float through the river systems many stagnant reservoirs to transform into juvenile fish, but restocked lakes sturgeons have reproduced in river systems with longer free flowing

stretches in the Kusa River basin in Georgia, and the researchers continue to hope when you start a sturgeon regeneration program, you are in it for a century, says Khuja who joined the team in Wisconsin to collect thin cliffs to chart hatchery genetics. It's a long term investment. Before Statics team finishes its work, members count out seventy three sturgeons to deliver to the Memomini tribe, whose reservation lies above Shiuano Dam. For thousands of years, the Mini people gathered

each spring for a feast and ceremony. We would wait for the sturgeon to come after the long which are months, says David Grignon, the tribe's historic preservation officer. When the dam was built more than one hundred thirty years ago, the sturgeon migration was blocked and the ceremony ceased. A century later, thanks to the state's recovery efforts, Wisconsin officials, in collaboration with the tribe, began hauling the fish around

the dams. They transport them up in big trucks and tanks each spring, says Grignon, and the tribe revised its ceremony that features dancers who mimic the movement of the sturgeons up the river. Tribal officials are also working to install a passage in one dam to restore the natural migration of sturgeons to the reservation, but for now, sturgeon generals like statig must serve as midwives too, trucking the

fish across unbreachable human boundaries. Ironically, the very industry that caused the decline of some many sturgeon species is now playing a key role in their comeback and his family's sturgeon farm outside of Milan, Italy, Gio Giovannini stands on a metal grill above the water and points beneath his feet to a fish named Cavallo. Today, most of the world's caviar is produced in aquaculture facilities like this one, farms that sturgeon advocates hope can play a part in

saving many European caviar species. The Gioini family raises three hundred thousand Adriatic Russians, stirlet and stellate sturgeons to sell on the global market. Most of those fish will be sold for caviar and meat, not Cavallo. Everyone had assumed Cavallo, which was sleek and jumped like a stallion, was a male, hence the masculine name. But in twenty twenty, after the family moved Cavallo from a site fed by spring water, to the farm's river fed tanks. Cavallo produced eggs for

the first time she was around fifty years old. Now she's contributing those eggs to the future of the species. We give this lady sturgeon river water, and after three four years, miracles happened Giovanni. He says, it is also something of a miracle that Cavallo and the other Adriatic sturgeons on the farm exist at all. Sergio's father, Jacinto, purchased Cavallo and around sixty other Adriatic sturgeons from fishermen on the Po River and its tributaries in the mid

nineteen seventies, before Sergo was born. They were among the last wild Adriatic sturgeons captured alive. The species was designated by the IUCN as critically endangered and possibly extinct in the wild in twenty ten. Though Giuscinto had experienced breeding trout and pike, he had no idea how to breed sturgeons in captivity. He had heard the Soviets had been successfully fertilizing Capcian Caspian sturgeon species since the eighteen sixties.

In the nineteen forties, their scientists figure out how do introduce ovulation with injections of pituitary home warns, and in nineteen sixty nine they retrieved the eggs using laparoctomies invasive surgeries to access the gametes, much like human caesarean sections. When Giuccinto sought the Soviets help for Adriatic sturgeons in nineteen seventy eight, they refused. Instead, he learned through trial and error with the assistance of French and Italian scientists.

In nineteen eighty eight, around the time wild sturgeon fishing was largely banned, he finally succeeded using a non invasive stripping method, applying gentle pressure to a ripe female's abdomen to squeeze the eggs out of the fish, no incisions required. Soon after, he distributed his first adriatic fingerlings to conservation organizations for restocking, and then in the nineteen nineties he began raising Adriatic and other species for caviare production as well.

It's thought every Adriatic sturgeon in the world today is descended from the breeding stock Chiacinto collected in the seventies. Looking back, says Baadas Strival, writer the World Wide fund for Nature's Sturgeon initiative lead. You can say the Giovannines have probably saved the Adriatic sturgeon. Experts hope these sorts of efforts can protect other species, such as the Russian and sterlet sturgeons and Belugas, the grandest, most coveted of

them all. Belugas came under crushing population pressure when sturgeon numbers crashed in the twentieth century as a result of overfishing and dam construction. A black market free for all then flourished with egg bearing beluga females estimated to have fetched as much as three million dollars each. Belugas could once be found and fished in northern Italy. Now they are gone from Italian rivers and found only in very small numbers in the Caspian and Black seas and on farms.

While the illegal caviar trade persists, expanding aquaculture makes it less. When I kill fish with my right hand, with my left, I can also be involved with conservation, says Sergio Giovannini's brother John, who along with Sergio, continues to provide breeding stock for ongoing Adriatic sturgeon reintroduction efforts. From the Giavigninis, the farmed sturgeons travel by truck to Cavier Processor Agrohitica Lombardo in the nearby industrial town of Calvisando, Augretique Death.

Lombardo processes almost processes almost thirty one tons of caviare each year. Unlike the Giuviannini's breeding program, the caviar harvest still requires killing the fish. The sturgeons are unloaded into a V shaped slaughtering trough, then move to processing rooms where employees clad in surgical gloves and gowns, remove the ovaries and pull out hundreds of thousands of glistening dark eggs, accounting for up to twenty five percent of a fish's

total weight. Then rinse, taste, grade whegh salt, hack, press, and finely can and label them for sale. During processing, tiny black rows scatter across the tables, wash buckets, and floor. When you buy caviar, you don't buy the eggs of sturgeon. You buy a perception, says Paolo Bronzi, president of the World Sturgeon Conservation Society. A luxury product, something special, just for rich people. Champagne caviar. A nice girl in the

grating room. One of the workers offers me a taste of ost cetra caviar from the critically endangered Russian sturgeon. It's true, it tastes like abundance birth salt sea life. In Kazakhstan on the banks of the Sir Dharya, the Kazakh Fisheries officials smoke cigarettes and weight sympathetic as kut Cahouja's struggles to keep his footing on the silty river bottom. He and Neelie drag a net beneath the surface. On their first pass, they pull up countless branches and cockleburrs,

along with a few minnows. At the river bank, they place each species they capture into a plexiglass container to measure and photograph, then untangle the net and wade back into the current, hoping that the next pass will dredge up a sturgeon no scientist has seen for more than fifty years and pave a path towards its recovery. Work like this is making an impact. Thanks to scientists and aquaculture experts like Cahoosia Static and the Giuvannines, sturgeon populations

have begun to recover. In eastern North America. Populations of Atlantic, Gulf and Lake sturgeons have all mounted comebacks from the lows of the past century. Reintroduced hatchery fish like those from Wisconsin's Wolf River have returned to their native watersheds everywhere from New York to Minnesota, to Germany to China, and in some places are beginning to reproduce for the

first time in decades. By twenty twenty one, after more than thirty years of restocking, scientists had discovered one beached egg bearing female and had detected juveniles in three Italian rivers, suggesting the restocked fish may have begun reproducing again in the wild. In April twenty twenty four, captive bread Yanksi sturgeons spawned in their native habitat for the first time, almost two years after a panel of international experts had

declared the fish extinct in the wild. The world's sturgeon generals haven't given up on the most critically endangered species either. Khoja helped identify the last Alabama sturgeon netted in the

wild in two thousand and seven. Biologists continued to comb the Alabama River for its namesake sturgeon and have found the fish's DNA in the waters there sad Lea Kuhuja won't find a seer Darya sturgeon on this expedition to Kazakhstan, but he plans to return the spring to look up river in Uzbekistan, where there are more shallow waters and

braided channels that are easier to see. Ample He believes they are there and that the next expedition may be the one that resurfaces that spindled prehistoric long sought fish. I'll recognize it the minute it breaks water, Cahucia says, and my head will spin on my neck. Ancient adaptations sturgeons have survived for millions of years. What accounts for

their staying power and sudden steep decline dwindling numbers. Once prevalent in fresh and salt water habitats across North America and Eurasia, sturgeon populations have dropped ninety four percent globally since nineteen seventy, with one species now extinct in the wild. Breeding blocked all sturgeon species, even those that spend most of their lives in salt water, migrate to spawn in fresh water. Rivers Dams obstruct the upstream journey of the

adults and the downstream drifting of developing hatchlings. Jurassic bodies. Physically, sturgeons haven't changed much for more than a hundred million years. When the fish were first described by modern science, researchers assumed they were sharks because of their cartilaginous skeleton and tail shape. Next, unraveling the mysteries of the Condo Congo. For decades, one of the world's biggest rainforests was largely

invisible to climate science. Now a new band of researchers raised in Central Africa is changing that, and what they're discovering there is revolutionizing our understanding of how to protect the planet. This article by Meilani Goobi. Within the dense canopy of the Congo Basin rainforest, the afternoon light began to fade, glinting off a soaring metal tower that rose

steeply out of the jungle. Measuring one hundred eighty feet tall, the narrow steel structure resembled a massive cellular network antennae, although it was outfitted with a collection of far more critical scientific sensors. The wind had picked up, causing the spire to sway and whine with each strong gust, But a biologist named fabres Kimbasa appeared undaunted after strapping into

a safety harness. He grabbed hold of a thin metal ladder and clamored briskly upward, leaving me to catch up as he raced toward a small platform at the very top. This particular structure is what's known as an eddy covariance flux tower. When it came online in October twenty twenty, it became the first effort to be located in the Congo Basin. For climate researchers who track greenhouse gas exchanges between the forest and the atmosphere. Such spires essentially act

like enormous stethoscopes. They're capable of tracking how much carbon dioxide is released and taken up by the forest to help calculate the world's emissions being sequestered back into the earth, among many other factors, and so every day Cambsa makes the nerve racking climb to check the equipment's readings, monitoring with precision. Now other forest breathes around him. When you look at the data, you get the sense that you now have a special connection with the forest, he says,

you can see things others don't. Today, after hours of baking beneath the hot equatorial sun, the rainforest seems to be exhaling, its canopy engulfed in clouds of mist. The recorded data showed a more specific trend over the past twenty four hours. Carbon dioxide levels in the area dropped substantially during the day as trees and other plants converted the greenhouse gas to oxygen during the photosynthesis, only to creep back up after sunset. This kind of work has

never been more vital. Tropical forests were once responsible for sequestrian roughly half of Earth's carbon stored on land, but their overall efficacy is declining since a peak in the nineteen nineties. The Congo Basin encompasses the world's second largest rainforest beyond behind the Amazon, spanning about five hundred million

acres of cross central Africa. Yet, while more than a thousand flux towers have been collecting data about gas exchange rates around the globe for decades, this region has been a blank spot until twenty twenty. Several years ago, an international consortium of researchers revealed that, based on a sample of tropical old growth forest plots across the Congo Basin, the rainforest appears to be storing carbon at a steadier rate than the Amazon, where the absorption rate has rapidly diminished.

But the researchers also noted that since twenty ten, the African rainforest has seemed to be following a downward path similar to its South American counterparts. To figure out what is really happening and perhaps offer some solutions, can Basa and a cohort of newly trained Congolese scientists now operate out of a revitalized research station within the Young Gambi Biosphere Reserve, a nine hundred square mile protected area in

the Democratic Republic of Congo DRC. The idea that kim Besa, who recently graduated from the nearby University of Kisangani, might be an important contributor to this research once seemed inconceivable. The DRC, where more than half of the Congo Basin rainforest lies, still suffers from deep poverty in a history of colonial exploitation, dictatorship, and conflicts that have both held back the development of a solid university system and restricted

employment and resources for local scientists. But as the ecological significance of the region has become more apparent, it has drawn increased attention from global conservation groups such as the Center for International Forestry Research, which is teamed with governments and universities to invest millions in infrastructure, technology, and training of researchers. This concludes readings from National Geographic Magazine for today.

Your reader has been Marsha. Thank you for listening, Keep on listening and have a great day.