East Siberian Sea runoff into the East Siberian Sea is relatively small at about 250 km/year that makes only 10% of the total runoff in all the Arctic seas of Russia. The largest contribution is from the Kolyma River at 132 km, followed by the Indigirka River at 59 km. Most runoff (90%) occurs in summer; it is concentrated near the coast, owing to the weak river currents, and therefore does not significantly affect the sea hydrology. The water exchange between the neighboring seas is as follows. The annual outflow to the Laptev Sea, Chukchi Sea and Arctic Ocean is 3,240, 6,600 and
East Siberian Sea ("Eschrichtius robustus"), beluga ("Delphinapterus leucas") and narwhal ("Monodon monoceros"). Major fish species are grayling and "Coregonus" (whitefishes), such as muksun ("Coregonus muksun"), broad whitefish ("Coregonus nasus") and omul ("Coregonus autumnalis"). Also common are polar smelt, saffron cod, polar cod, flounder and Arctic char. The coast of the East Siberian Sea was inhabited for ages by the native peoples of northern Siberia such as Yukaghirs and Chukchi (eastern areas). Those tribes were engaged in fishing, hunting and reindeer husbandry, as reindeer sleds were essential for transportation and hunting. They were joined and absorbed by Evens and Evenks around the 2nd century