CNN
 — 

When scientists heard stories that a big, mysterious fish had been caught in Cambodia in 2020, pleasure stirred. May this be the “Mekong Ghost,” they requested – an elusive fish that hadn’t been seen since 2005 and was feared extinct?

Pictures of the fish and its telltale identifiers – an odd-shaped mouth and a protruding knob at its jaw – appeared to verify it.

However the fish, which might develop as massive as 66 kilos, was offered earlier than scientists may get a more in-depth look. It didn’t “really feel like definitive proof,” stated Zeb Hogan, a analysis biologist on the College of Nevada, Reno, and head of the US government-funded Wonders of the Mekong venture, an initiative to review and preserve one of the crucial biodiverse rivers on this planet.

Three years later, they struck gold.

Cambodian fishermen caught two fish within the Mekong River, measuring between 11 and 13 kilos and two to 3 toes lengthy. This time researchers had been in a position to buy and study the fish for themselves.

“Though the fishermen … hadn’t seen the fish earlier than, they knew that they’d one thing exceptional, uncommon. They knew that it was price contacting us,” stated Hogan, a part of a world staff of scientists who work with the Cambodian fisheries division, in an interview with CNN.

“As quickly as anybody who was a part of this seek for this fish noticed the photographs, we knew what it was.”

The researchers revealed their findings on Tuesday in a examine within the Organic Conservation journal.

It was a second of celebration for the staff, which works to guard the Mekong, one of many world’s longest rivers and a lifeline to tens of tens of millions of individuals.

Which means “Mom of Rivers” in Thai and Lao languages, the Mekong winds by means of a number of Southeast Asian international locations and is extraordinarily wealthy in biodiversity. Nevertheless it additionally faces varied challenges together with hydropower growth, overfishing and habitat degradation.

These challenges are why scientists have lengthy fearful that the “Mekong Ghost,” a critically endangered large salmon carp that may measure as much as 4 toes lengthy, may have been quietly worn out as years handed with no sighting.

The fish, native to the Mekong, has been shrouded in thriller because it was formally named in 1991. Since then, fewer than 30 people have been recorded, making it a extremely uncommon species, in accordance with a press launch from the College of Nevada, Reno.

Hogan’s staff of researchers – who additionally examine different species and components of the Mekong’s surroundings – have saved an eye fixed out for the large salmon carp, perusing fish markets and doing outreach applications with native fishermen. Hogan himself, who has devoted a lot of his profession to finding out fish within the Mekong River Basin, has solely seen it as soon as within the early 2000s.

“I’ve been searching for it since then, sort of fascinated by it as a result of it’s a really uncommon large fish,” Hogan stated. “I believed it was most likely extinct, and so to listen to that it had been discovered once more – I’ve been ready 20 years for that information.”

“It’s an indication of hope,” he added. “It implies that it’s not too late.”

The examine’s lead creator, Bunyeth Chan from Cambodia’s Svay Rieng College, echoed this sentiment, saying in a press launch: “The rediscovery of the large salmon carp is a cause for hope, not only for this species however for your entire Mekong ecosystem.”

There’s so much researchers nonetheless don’t know, like what number of large salmon carp really exist or the place these populations reside.

The three fish that had been discovered between 2020 and 2023 had been discovered exterior their regular vary – which may both imply there are extra fish residing in areas beforehand unknown or that they migrated there from neighboring Laos and Thailand.

And although it’s uncommon to search out three particular person fish in fast succession after the species disappeared for almost 20 years, Hogan credit this to the work they’ve been doing on the bottom – constructing good relationships with native communities who know to contact them in the event that they spot something out of the atypical.

However researchers say extra must be performed because the Mekong fights off threats from varied fronts, together with local weather change, with the area dealing with extra extreme flooding and drought every year consequently.

Human tasks reminiscent of hydropower dams and sand mining have additional degraded marine habitats and disrupted life for the Mekong’s greater than 1,100 fish species, lots of that are discovered nowhere else on Earth.

Almost a fifth of the Mekong’s fish are threatened with extinction, in accordance with a report launched in March this yr, a collaboration between 25 organizations together with the World Wildlife Fund and Wonders of the Mekong.

Cambodia can also be not a straightforward place to be an environmental activist. Many have been jailed or killed through the years as they search to lift consciousness about corruption and enterprise tasks which have impacted the surroundings in a nation the place little political opposition is tolerated.

Earlier this yr, 10 younger activists from the group Mom Nature Cambodia had been sentenced to as much as six years in jail, every on fees of conspiring in opposition to the state, a conviction that was condemned by opposition politicians in exile and distinguished youth environmentalist Greta Thunberg.

Researchers behind the most recent report hope the large salmon carp’s rediscovery can construct momentum for extra examine and conservation motion – together with creating a world staff throughout Cambodia, Laos and Thailand to additional examine the “Mekong Ghost.”

“This fish is an indicator of river well being as a result of it’s a big fish, it’s susceptible,” stated Hogan.

“Nevertheless it’s additionally emblematic of all of those different fish that happen within the space which can be key fishery species and which can be crucial for folks’s livelihoods, and crucial for folks’s vitamin and meals.”