Research beyond the Arctic Circle: studying the wintering of ichthyofauna in the Gulf of Ob

 

The Ob Bay is the most valuable and largest freshwater habitat for whitefish in the world. Due to the climatic features of its location, the Ob Bay is locked in ice for about 9 months a year. It is here that the fish concentrate and spend the long winter months, while most of the reservoirs of the middle and lower reaches of the Ob are covered by freezes that extend for several thousand kilometers. All this time, the ichthyofauna lives in conditions of low oxygen.

 

Every year, from April to May, industry scientists go beyond the Arctic Circle to assess how the ichthyofauna has survived the winter. For more than a month, scientists continuously monitor the populations of the main commercial fish and their habitat.

 

During fishery research, employees of the Tyumen branch of VNIRO conducted a full biological analysis and mass measurements of fish from the commercial catches of the local fish factory. They collected hydrochemical and hydrobiological samples for subsequent research, including determining the food supply of fish. Every day, specialists monitored abiotic indicators, primarily the oxygen level in the water.

 

Very soon, small rivers flowing into the estuary will be freed from ice. "Fresh breath" will allow the fish to leave their wintering grounds and begin a long feeding and spawning migration along the filled floodplain and the system of sors of the Lower Ob basin. This important stage in the life cycle of ichthyofauna will also take place under the control of fishery science.

 

The complex data obtained will provide information on the state of fish stocks and their habitat. They will form the basis for the formation of generally permissible and recommended catches for subsequent years.

 

Press service of VNIRO