
© Zeb Hogan
The giant freshwater stingray is the largest freshwater fish in the world
Scientists are trying to understand why 70 giant freshwater stingrays, some as big as a car, have been
found dead in Thailand over the past few weeks. The die-off has been taking place in the Mae Klong River.
Thai officials have found the river to be slightly more acidic than normal, but aren't sure if that could be the cause. Some speculate that the rays may have been poisoned by cyanide or succumbed to a recent spill from an ethanol plant.
"One thing is clear: a reduction of pollution from surrounding factories is needed to improve the health of the river and save the stingrays in the long term," Zeb Hogan, host of the Monster Fish series on Nat Geo Wild, said.
The
WWF says that these rays are being increasingly isolated into separate groups due to construction of
large hydropower dams, reducing genetic diversity. They are vulnerable to siltation as they spend much of their time along the river's sandy bottom. And they can be caught up in fishing activities such as longlines and gill nets, and may be killed as bycatch.
Comment: A few days ago huge hailstones and 3000 lightning strikes hit Brisbane, Australia.