Short answers, pulled from the story.
The Sea of Okhotsk covers an area of 1,583,000 square kilometers with a mean depth of 859 meters and a maximum depth of 3,372 meters. It sits between Russia's Kamchatka Peninsula on the east and Japan's island of Hokkaido on the south.
Cold air from Siberia creates sea ice in the northwestern Sea of Okhotsk during winter months while freshwater from the Amur River lowers salinity levels which raises the freezing point of surface water. As ice forms it expels salt into deeper layers creating heavy water that flows east toward the Pacific Ocean.
Russian explorers Vassili Poyarkov visited the Sea of Okhotsk in 1639 followed by Ivan Moskvitin in 1645. Vitus Bering's Second Kamchatka Expedition systematically mapped entire coastline starting in 1733.
The Sea of Okhotsk has warmed in some places by as much as 3 degrees Celsius since preindustrial times rising three times faster than the global mean average temperature increase. Rising temperatures inhibit formation of sea ice and drive fish populations further northward causing salmon catches on the northern Japanese coast to fall 70 percent over fifteen years.
The Peanut Hole area spans approximately 200 kilometers wide and 300 kilometers long at center of Sea of Okhotsk lying outside Russian exclusive economic zone allowing any country to fish there since 1991. The Russian Federation petitioned United Nations declaring it part of continental shelf in November 2013 with full Commission ruling favorably for Russia in March 2014 regarding boundary disputes.