Key Takeaways:
– The giant salmon carp, known as the ‘Mekong ghost’, thought extinct has resurfaced.
– Scientists discovered three specimens in Cambodian waters from 2020 to 2023.
– The Mekong River is home to the most diverse array of megafish on our planet.
– Dams, overfishing, and climate change are significant threats to these river giants.
Rediscovery of Mythical Fish
The giant salmon carp, commonly known as the ‘Mekong ghost,’ can be considered a myth no more. This aquatic titan, akin to the eponymous character in the Rip Van Winkle story, had seemingly faded into folklore after not being documented since 2005. This disappearance led many to speculate that this species had silently slipped into extinction.
However, recent discoveries by scientists have brought a renewed sense of optimism for the survival of this marine creature. Between 2020 and 2023, researchers confirmed the discovery of three individual instances of the ghost fish caught in Cambodian waters. Their findings, published in the November issue of Biological Conservation, have renewed hope for the megafish’s continued existence.
Working with Local Communities
Researchers seeking the elusive species worked hand in hand with local fishing communities. They conveyed their interest in obtaining “pa sanak,” the local term for the carp. In 2020, their efforts bore fruit when a fisherman contacted the Cambodian Fisheries Administration with news about an unusual catch. However, without the physical specimen, the scientists couldn’t definitively identify its species based solely on photographs.
The situation improved in 2022 and 2023 when two more specimens were provided by fishermen, allowing scientists to confirm the identity of the Mekong ghost. “The existence of Aaptosyax in the Mekong after its long-disappearance took me by surprise and excited me” said Chan of Svay Rieng University in Cambodia.
Distinct Features and Challenges
The giant salmon carp, characterized by its distinctive hooked jaw and salmonlike body, can grow up to 1.3 meters long and weigh over 30 kilograms. The Mekong River, its habitat, houses a larger variety of megafish than any other river, including the Mekong giant catfish and the giant freshwater stingray.
Despite the optimistic discovery, the future of these aquatic behemoths remains lined with challenges. Many of these species, including the giant salmon carp, are migratory, relying on seasonal movement to find food and reproduce. Unfortunately, the construction of dams throughout the Mekong River system has disrupted these migrations. Climatic change and overfishing further complicate their survival.
A Glimmer of Hope
Interestingly, the fact that the recently discovered giant salmon carps were found outside their hypothesized historic range suggests the species might be more widespread than initially presumed. The Cambodian government, recognizing the significant discovery, has added the giant salmon carp to its list of protected species. This rediscovery could also trigger renewed efforts to protect the fragile Mekong ecosystem.
“This discovery isn’t solely about the survival of the salmon carp but also acts as a call to protect one of the world’s most significant biodiversity hotspots,” says study co-author Zeb Hogan, a fish biologist at the University of Nevada, Reno, who leads the USAID-funded Wonders of the Mekong project. With concerted efforts, it is hoped that this rediscovery can help salvage and restore the Mekong’s rich biodiversity.