Kamchatka fish hatchery producing coho fry in thermal waters
Paratunsky fish hatchery located in Kamchatka has released to the sea coho fry which has been experimentally grown in thermal waters, reports www.fishnet-russia.com (www.fishnet.ru) with reference to Novosti.
More specifically, the coho fry which have hatched from roes stocked into the hatchery in autumn 2008 have been cultured in the water of plus 12 degrees Celsius, 4 degrees up on usual water temperature used for coho breeding.
As a result, the fry has gained a double weight of 10 grams as the average size of fry released into the rivers in the previous years amounts to 5 grams.
The water temperature has been increased due to the heat of geothermal waters flowing into the hatcheries heat exchangers.
Almost all wild salmons spawn in the waters of Kamchatka, they are coho, chum, pink, Chinook and sockeye. Coho is the only Pacific salmon whose fry do not migrate to the ocean in the year of their hatching from the roes, but remain in the fresh water of the rivers until the age of 2.
Specialists say that the experiment of growing fry to double weight in thermal waters will allow the fish to spawn not in two years, but already in the next year as small coho are supposed to migrate to the ocean this summer thus omitting several months of staying in fresh waters. In the oceanic waters coho will feed up in the course of the whole year and return to the native river to spawn there next summer.
In Kamchatka salmon reproduction activities are carried out by five fish hatcheries. In the year 2008 they stocked 36.6 million roes of coho, chum salmon, sockeye and Chinook. This summer the fry will escape to the ocean to feed there and return back to Kamchatka rivers for spawning where the fish will be harvested in summer 2009.
In summer 2009 Kamchatka-based fish hatcheries are planning to stock 43.6 million roes of valuable species.