What if the Kurile Islands weren't there?
The Sea of Okhotsk is a double layered sea with a thin surface layer of low salt content water created by the Amur River with high salt content water underneath.
What it would be like if there were no Kurile Islands?
The low salt water which is currently stopped by the Kurile Islands would flow into the Pacific Ocean, and the Sea of Okhotsk might not have become a double layered sea.
Then, we might not be seeing the drift ice like this.