The sturgeon and redfish populations of the Caspian Sea are under serious threat. Once home to 80% of the world’s sturgeon stocks, the sea has now seen many of its species added to the Red List of endangered species. Experts warn the situation is far more critical than it appears.
Azerbaijan hosts six species of sturgeon, but their numbers have dropped sharply in recent years. Specialists caution that if the trend continues, all of them could disappear from the wild entirely. While fish farms are working on artificial breeding programs, these efforts cannot fully replace natural reproduction.
Iran has linked the decline of sturgeon, redfish, and sprat populations to pollution caused by Caspian littoral states. However, experts stress that contamination is only part of the problem.
Suleyman Suleymanov, head of the hydrobiology laboratory at the Institute of Zoology of Azerbaijan’s National Academy of Sciences, told Bizim.Media that the primary cause is the loss of natural spawning grounds.
“Pollution plays a role, of course. Artificial breeding helps preserve populations, but the Caspian ecosystem is undergoing major changes due to human interference, leading to fish mortality,” he said.
Suleymanov noted that artificial propagation can only prevent total extinction, not restore healthy wild populations. He cited his recent visit to the U.S., where spawning seasons are strictly protected and people can observe the process on screens. In Azerbaijan, however, sturgeon are often caught before they have laid their eggs, with immature roe ending up on dining tables.
The Kura River, the Caspian’s largest inflow, has lost 50–60% of its volume, further reducing spawning areas. “During spawning, fish are blocked by the Varvara Reservoir dam, which stops their migration. Redfish, in particular, die after spawning. Their roe must be replenished naturally, but when the cycle is interrupted, the species declines,” Suleymanov stressed.
On a more positive note, he reported that sprat stocks in the Caspian are currently stable. Previously, they had plummeted due to invasive species from the Black Sea destroying their food base, a problem now resolved.
Suleymanov concluded that without restoring the Caspian’s natural ecosystem, artificial methods alone will not be enough to save its sturgeon and other endangered fish.
