Sakhalin river. Photo: Sakhalin Ecowatch
Pink salmon in southwest Sakhalin: fishery closed, rivers empty
Tuesday, August 02, 2022, 07:00 (GMT + 9)
The Sakhalin Ecological Watch surveyed pink salmon spawning grounds in 14 rivers flowing into the Tatar Strait in the southwestern part of the island.
These are the rivers of the Kholmsky and Tomarinsky districts - Krasnogorka, Parusnaya, Belinskaya, Novoeniseyskaya, Ilyinka, Cheremshanka, Tomarinka, Chernaya Rechka, Novoselka, Chekhovka, Krasnoyarka, Kostroma, Pionerskaya, Yablochnaya. The total area of pink salmon spawning grounds in them is about 2 million square meters.
The survey was conducted as part of the annual public monitoring of the filling of Sakhalin rivers with pink salmon producers.
At present, in the rivers of the southwestern coast of Sakhalin, pink salmon should be actively spawning, and its density should be maximum. But the rivers turned out to be empty, there are practically no pink salmon in them. Only in three of the fourteen surveyed rivers was it possible to reliably identify a small amount of pink salmon that came to spawn - these are the Pionerskaya, Krasnoyarka and Chekhovka rivers. The last two have salmon fish hatcheries (LRZ), which protect fish in the rivers from illegal fishing. At the same time, hatcheries releasing pink salmon are also present on two more surveyed rivers - Kostroma and Chernaya Rechka, but ecologists did not find pink salmon spawners in them, as well as the protection of natural spawning grounds.
But even in those three rivers where pink salmon was found, its quantity is extremely small and is not capable of providing full-fledged natural reproduction, and besides, in Krasnoyarka and Chekhovka, fish hatcheries seize a significant part of pink salmon producers.
Anatoly Dekshtein, an ichthyologist at Sakhalin Ecowatch, notes that the surveyed rivers no longer resemble salmon. The bottom substrate is pebbles, which the spawning salmon in their mass loosen with their bodies, creating conditions for the normal maturation of eggs, is now compacted, silted and covered with brown algae. Not only pink salmon is missing, there are also no other common inhabitants of salmon rivers - podkamenka (young salmon), rudd, Dolly Varden, lampreys, and Siberian trout. Bears, amateur fishermen and poachers have left the rivers - they have absolutely nothing to catch there.
This year, even a complete ban on fishing here, adopted for the first time for a generation of pink salmon in even years, did not help to fill the spawning grounds of southwestern Sakhalin. In all previous even-numbered years, officials of the Federal Agency for Fishery and the regional government allowed the commercial catch of pink salmon here with almost no restrictions - for example, until 2020 it was possible to use fixed seines up to 3 km long (only once, in 2018, their length was reduced to 1, 5 km). In 2010, the catch of pink salmon in the southwest of Sakhalin amounted to 2940 tons, and in 2020 - 1091 tons.
Photo: Sakhalin Ecowatch
Simultaneously with the decline in catches (three times over 10 years), the filling of spawning grounds also decreased. According to state monitoring data, in 2010 the spawning grounds of the rivers of the Kholmsky district were filled with pink salmon by an average of 40%, and the rivers of the Tomarinsky district - by 23%. In 2020, these figures fell to 4% and 3%, respectively. And now, in 2022, the logical result is that a whole generation of pink salmon from a large fishing area is absent from spawning grounds and will not give offspring.