„Prom“ for fingerlings
September 1, 2015
Indeed, during the last three years over three million chum salmon fingerlings were released into the rivers of the Sakhalin Island where onshore exploration activities were underway. This season, some of young chum salmon were reared at the Pobedinsky Hatchery for the first time. It is precisely the place on the Sakhalin Island where the Gazprom Geologorazvedka experts decided to go and to supervise what is going on in a so-called ‘finny prom’.
The Pobedinsky Hatchery is located in the picturesque forested area 20 kilometers away from Pobedino settlement (Smirnykhovsky District, Sakhalin Region). Bears are frequent and unwelcome guests here; this is why it may be not quite safe to walk far from the salmon breeding plant.
The hatchery employs 13 people who live with their families in houses near the workplace. So every member of this tiny community, except children of course, is busy with fish farming.
This is the most important part of the hatchery – a rearing area divided into 35 tanks. Newly hatched eggs – baby salmonids called alevin – start their lives here. Each tank contains roughly about 400 thousand fries (grown-up alevins).
Fish breeding experts keep an eye on little chum salmon all the time. Fish food, nutritious and rich in minerals, gets into the tanks in an automatic mode and almost non-stop.
Fries ‘are moved’ to the hatchery in batches in the end of spring. Their release usually starts in the second half of June and lasts for a couple of weeks. Five or four tanks, full of chum salmon fingerlings, are released into the Rybovodny stream every two days.
Before little fish enters the adulthood, the experts do some biological checks. First, fingerlings are examined under microscope to make sure that they are healthy and parasite-free. In the photo – Ivan Kolesov, fishery manager of the 2nd grade.
Later on, juvenile salmonids are weighed and measured and then an average value is obtained. By the ‘prom’, a fingerling should put on between 700 and 800 milligrams of weigh and grow up to 5 centimeters long. Little chum salmon of this size will be hard to catch for such predators as rudds and, subsequently, they will have more chance to survive. Ulyana Radchenko, Ivan Kolesov’s spouse and workmate, and also fishery manager of the 2nd grade, gives him a helping hand.
Now everything is ready for a big leaving day. Fanis Sakhautdinov, Environmental Protection Division Head at Gazprom Geologorazvedka (right), together with Ivan Kolesov remove protection beams. Alla Mamaeva, Chief Fishery Manager at the Pobedinsky Hatchery, supervises the whole process. Washed out by the water, fingerlings make their way to the channel and the adult life!
Fanis is watching little fish swimming in the channel; after a while, they will reach the Rybovodny stream, and the next step will be the Poronay River, a big basin in Sakhalin, popular with spawning fish. By the way, fingerlings are usually released in the evening, when it’s dark, to make the entire process much less stressful for the ‘graduates’.
Here in the Poronay River the fingerlings will grow up a little and will have more strength to start their big journey – migrate downstream to the Sea of Okhotsk. Well, only the toughest and the luckiest will eventually get there as a lot of death traps are waiting for chump salmon in the wild.
Adult salmonids will spend three to seven years in the Sea of Okhotsk, and later on, driven by a powerful sense of homing, will return to their natal place for spawning.
Fingerlings entered the Poronay River through this channel; years later, the grown-ups will swim back to the Pobedinsky Hatchery via the same old channel. Only one per cent of fish adults manage to come back home, because of unforgiving natural selection in the wild. However, the hatchery is considered to be highly productive.
Besides, in all scenarios in the wild chum salmon dies shortly after spawning. In the weaning unit fish eggs are collected for subsequent fertilization; and fish is being prepared for sale. In the photo – the incubators where fertilized eggs are reared from September to February.
Later on, fries will find themselves in the hatchery – cleaned, decontaminated and ready to welcome the newcomers.
Viktor Shagalov, Director of the Pobedinsky Hatchery (right) hopes that the cooperation with Gazprom Geologorazvedka will continue in the future. Thanks to the business relationship with Russian energy companies, the fish breeding plant is fully loaded; au contraire, government contracts for caviar production cover just three-fourth of the hatchery’s capacities.
Fanis Sakhautdinov and Irina Yemelyanova, Gazprom Geologorazvedka experts, wished all the best to the ‘graduates’. No doubt that the compensatory release of fingerlings will help repopulate the waters of the Sakhalin Island and bolster the overall numbers of chum salmon, which will have a great impact on the local fishing industry.