The Ob was once teeming with sturgeon, but more recently the 'Tsar Fish' has become an endangered species in the mighty river.
State of emergency declared in city of Nizhnevartovsk, which suffers worst flooding in its history.
On 1 May, the 'Ob Sea', close to Novosibirsk, was completely clear of ice.
With a larger arch span than any in Europe, it is the new signature of Siberia's largest city.
Demands increased on 3 August for a 'state of emergency' to be declared on the world's fifth longest river due to a catastrophic shortage of water.
Floodwater from Ob River is black from spill as emergency workers flight to limit damage.
This vast region has some of the world's greatest rivers, but they could do much more to support the economic regeneration and security of the country.
Spectacular ice show attracts mesmerised crowds of onlookers in Surgut as world’s 7th longest river defies spring.
Mysterious 'lakes of black oily liquid' found near Nizhnevartovsk.
New road and rail link over the Nadym River.