Northeast Siberian coastal tundra
This coastal region borders the Laptev Sea and the East Siberian Sea , both marginal seas of the Arctic Ocean , from the Lena River delta in the west to the Kolyma River delta in the east . 
<triplet> Laptev Sea <subj> Arctic Ocean <obj> part of <triplet> East Siberian Sea <subj> Arctic Ocean <obj> part of <subj> Kolyma River <obj> inflows <triplet> Arctic Ocean <subj> Laptev Sea <obj> has part <subj> East Siberian Sea <obj> has part <triplet> Lena River <subj> Laptev Sea <obj> mouth of the watercourse <triplet> Kolyma River <subj> East Siberian Sea <obj> mouth of the watercourse