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 the sea centre, reaching 31–32‰ at its northern outskirts. Salinity decreases in summer by some 5‰ due to the snow melting. It also decreases by some 5–7‰ from the sea bottom to the surface. There are constant currents at the sea surface directed from west to east. They are weak and thus can temporarily change direction due to the wind. The tides are semidiurnal (rising twice a day) with the amplitude between 5 and 25 cm. The tidal wave weakens toward the coast due to shallow waters. The sea level is maximal in summer, due to the river runoff, and