Rauchua (Rauchuvan, Big Baranikha)
Rauchua (Rauchuvan, Big Baranikha) – a river in the Chukotka Autonomous Okrug, Russia. It meets the East Siberian Sea via several channels. R. stems from the northern slopes of the Anyui Ridge, flowing through the lake of Rauchuvagytkyn. Its total length is approx. 320 km. In the upper and middle streamways of the river, this is the mid-mountain tundra with pebbled spits, rifts, and willow thickets along creek banks and midstream sandbanks. At its mouth, the river enters the maritime plain covered with a mass of lagoon-cave-in lakes, creeks, and halophytic meadows. The depth in the coastal waters of the East Siberian Sea is 1.5–5 m. Wind-surge sea level fluctuations is 1–1.5 m. The basin area is 15,400 km2. The river freezes in October and stays under ice until May. It is nourished due to snow and rains.
The lower reaches of the river are approached by Pacific salmons – pink and chum, as well as by anadromous loaches – malma trout and Tarantsev loach. Deep thermal erosion lakes are inhabited by Arctic char. In the lower reaches of rivers and lakes, there are various whitefish species: Siberian whitefish, broad whitefish, Arctic cisco, humpbacked whitefish, East Siberian grayling, rainbow herring, capelin, and minnow. The fish stocks of the lower reaches of R. are undermined by excessively long-term fishing.