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 scarce due to the harsh climate. The summer plankton bloom is short but intense, producing 5 million tonnes of plankton in August and September, whereas the annual production is 7 million tonnes. The nutrients in water are mostly provided by river discharges and coastal erosion. The plankton species are dominated by the Pacific species of copepods. The sea shores and icefields host ringed seals ("Phoca hispida"), bearded seals ("Erignathus barbatus") and walruses ("Odobenus rosmarus") along with their predator, polar bear ("Ursus maritimus"). Birds include seagulls, uria and cormorants. Sea waters are often visited by bowhead whale ("Balaena mysticetus"), gray whale