A record night on the Rioni: 117 juvenile sturgeons
Never before had so many juvenile sturgeons been caught on the Rioni in one night. In 2026 the team caught more sturgeons than in the previous eight years combined.
A research team led by Fauna & Flora and its local partners caught 117 juvenile sturgeons in a single night on the Rioni River. The organisation announced the record on 13 October 2026. Every fish was sampled for DNA, measured and returned to the river. Juvenile sturgeons mean that sturgeon are still breeding in the Rioni.
What happened on the Rioni?
Fauna & Flora has worked to save the Rioni’s sturgeon since 2017. Its team works on the river from early spring to autumn, often until well after midnight. On one such night it caught 117 juvenile sturgeons. The organisation calls this a record. The date of the night is not given.
The record night is part of a bigger year. In 2026 the team caught more sturgeons than in the previous eight years combined. Dozens of other juveniles were recorded on other nights in recent months. Every fish was sampled for DNA and measured, then released unharmed into the river.
The juveniles are only a few centimetres long. Their bodies are slimy and covered in sharp spines. They look strange, but for the researchers every one of them is a prize.
Why do juveniles matter so much?
A juvenile sturgeon found in a river is evidence of spawning. Early in 2018, during a pilot project, the team carried out the first baseline study of Georgia’s sturgeons. Very little was known about the Rioni sturgeon then, compared with those of the Danube and the Garonne. It was not even clear whether sturgeon still bred in the Rioni at all.
The first answer came during that pilot. The team caught a tiny juvenile stellate sturgeon (Acipenser stellatus). The species is named for the star-like markings on the flanks of the adult fish.
In 2020, within less than a month, two ship sturgeons (Acipenser nudiventris) were caught in the Rioni. Until then, many believed the species was extinct. Both fish were juveniles, each estimated to be less than three years old. That raised the prospect that the ship sturgeon might still breed in the Rioni.
Genetic studies show that at least three species spawn in the Rioni today: Russian sturgeon (Acipenser gueldenstaedtii), stellate sturgeon and ship sturgeon. For the details, see our article on the new Rioni protected area.
Who works out which species it is?
Samples from every captured sturgeon go to Ilia State University for genetic analysis. The analysis helps identify the species and shows which sturgeons survive in the Rioni. Tamar Beridze of the university also analyses environmental DNA (eDNA) samples to find out which species live in Georgia’s rivers.
Fishers collect data too. The monitoring team patrols the river regularly and asks fishers to report and release any sturgeon they catch, to use only legal fishing methods, and to help collect data on wild sturgeon. The ship sturgeon in the photo above was found in the Rioni by a local fisher. If you fish on the Rioni and catch a sturgeon, report it and let it go.
Why is the Rioni so important?
There are 27 sturgeon species in the world, and all but four are close to extinction. According to the IUCN Red List, no other group on Earth is so critically endangered. Sturgeon once lived in all of Europe’s major rivers. Overharvesting, poaching and the loss of spawning grounds have almost wiped them out.
Today the Rioni is one of the last three sturgeon refuges in the whole of Europe. Fauna & Flora counts four, possibly five, critically endangered sturgeon species still surviving there. For the organisation, the record night and the 2026 catches are further proof that the Rioni is crucial for these fish.
The spawning ground gets protection
On 28 May 2026 parliament approved a 554-hectare protected area on the Rioni in Samtredia Municipality, Imereti. It covers the stretch where sturgeon spawned historically. In 2024 a protected area was also created in the Rioni delta, where the river meets the Black Sea.
Both areas connect with an existing marine protected area. Together they form a network of river, coastal and marine habitats. Sturgeon need exactly that: they hatch in the river, move out to sea, and return upstream as adults to spawn.
What remains unclear?
Date and species. The announcement does not say on which night the 117 juveniles were caught, or which species they belonged to. It gives no results of the genetic analysis.
Numbers. 117 caught fish is not a population estimate. Neither this announcement nor the other sources we used give an estimate of sturgeon numbers in the Rioni.
Number of species. Fauna & Flora names “four, possibly five” sturgeon species in the Rioni. A 2023 genetic study confirmed spawning in the Rioni for three species, while beluga (Huso huso) were found only as adults in Georgia’s Black Sea waters.
Sturgeons are not in this atlas. See other news for more records.
