The Sea of Okhotsk covers an area of 1,583,000 square kilometres (611,000 sq mi), with a mean depth of 859 metres (2,818 ft) and a maximum depth of 3,372 metres (11,063 ft). It is connected to the Sea of Japan on either side of Sakhalin: on the west through the Sakhalin Gulf and the Gulf of Tartary; on the south, through the La Pérouse Strait.
In winter, navigation on much of the Sea of Okhotsk becomes difficult or impossible due to the formation of large ice floes, because the large amount of freshwater from the Amur River lowers the salinity of upper levels often raising the freezing point of the sea surface. The distribution and thickness of ice floes depends on many factors: the location, the time of year, water currents, and the sea temperatures.
With the exception of Hokkaido, one of the Japanese home islands, the sea is surrounded on all sides by territory administered by the Russian Federation.
The International Hydrographic Organization defines the limits of the Sea of Okhotsk as follows:On the Southwest. The Northeastern and Northern limits on the Japan Sea [In La Perouse Strait (Sôya Kaikyô). A line joining Sôni Misaki and Nishi Notoro Misaki (45°55'N). From Cape Tuik (51°45'N) to Cape Sushcheva]. On the Southeast. A line running from Nosyappu Saki (Cape Noshap, 43°23'N) in the Island of Hokusyû (Yezo) through the Kuril or Tisima Islands to Cape Lopatka (South point of Kamchatka) in such a way that all the narrow waters between Hokusyû and Kamchatka are included in the Sea of Okhotsk.
Some of the Sea of Okhotsk's islands are quite large, including Japan's second largest island, Hokkaido, as well as Russia's largest island, Sakhalin. Practically all of the sea's islands are either in coastal waters or belong to the various islands making up the Kuril Islands chain. These fall either under undisputed Japanese or Russian ownership or disputed ownership between Japan and Russia. Iony Island is the only island located in open waters and belongs to the Khabarovsk Krai of the Russian Federation. The majority of the sea's islands are uninhabited making them ideal breeding grounds for seals, sea lions, seabirds, and other sea island fauna. Large colonies, with over a million individuals, of crested auklets use the Sea of Okhotsk as a nesting site.
The Okhotsk culture is an archaeological coastal fishing and hunter-gatherer culture of the lands surrounding the Sea of Okhotsk (600–1000 CE in Hokkaido, until 1500 or 1600 CE in the Kurils).
Some believe that Mishihase was living in the area.
Russian explorers Ivan Moskvitin and Vassili Poyarkov were the first Europeans to visit the Sea of Okhotsk (and, probably, the island of Sakhalin) in the 1640s. The Dutch captain Maarten Gerritsz Vries in the Breskens entered the Sea of Okhotsk from the south-east in 1643, and charted parts of the Sakhalin coast and Kurile Islands, but failed to realize that either Sakhalin or Hokkaido are islands.
The first and foremost Russian settlement on the shore was the port of Okhotsk, which relinquished commercial supremacy to Ayan in the 1840s. The Russian-American Company all but monopolized the commercial navigation of the sea in the first half of the 19th century.
The Second Kamchatka Expedition under Vitus Bering systematically mapped the entire coast of the sea, starting in 1733. Jean-François de La Pérouse and William Robert Broughton were the first non-Russian European navigators known to have passed through these waters other than Maarten Gerritsz Vries. Ivan Krusenstern explored the eastern coast of Sakhalin in 1805. Mamiya Rinzō and Gennady Nevelskoy determined that the Sakhalin was indeed an island separated from the mainland by a narrow strait. The first detailed summary of the hydrology of the Okhotsk sea was prepared and published by Stepan Makarov in 1894.
American and French whaleships, as well as a few German, Russian, and British, hunted whales in the Sea of Okhotsk between 1845 and 1909. They targeted two species: the right whale and the bowhead whale, the former primarily in the southern half of the sea and the latter in the northern half — though the two overlapped in the northeastern part of the sea from 56°30' to 57° N and 150 to 154° E. Bowheads were first caught in 1847, and dominated the catch between 1849 and the late 1860s. Beginning in the mid-1850s they caught the occasional gray whale, and made attempts to catch humpback, fin, blue and killer whales as well but were rarely successful. Beluga whales were also taken opportunistically. Between 1850 and 1853 the majority of the fleet went to the Bering Strait region to hunt bowheads, but intense competition, poor ice conditions, and declining catches forced the fleet back to the Sea of Okhotsk. From 1854 to 1856, an average of nearly 150 vessels cruised in the sea each year. As catches declined between 1858 and 1860 the fleet shifted back to the Bering Strait region; by the mid-1860s few ships cruised in the sea. In the 1860s the Russians also established a couple whaling stations in Tugur Bay, which operated until the mid-1870s. American and French ships, meanwhile, had abandoned the sea in the early 1870s. Several vessels returned in 1874 but the bowhead catch was so poor that season that they again deserted the area for the rest of the decade. When they returned in the 1880s and 1890s they mainly caught right whales, rarely venturing north to search for bowheads.
Ships usually arrived in April or May. They first made their way to the northeastern part of the sea to hunt bowheads along the pack ice, then worked through the ice either to the northeast to Northeast Gulf (Shelikhov Gulf), north to Tausk Bay (Taui Bay), or west to Jonas Island (Iony Island). After spending a few weeks cruising around Jonas Island, many followed the retreating ice to the south and converged on the bays to the south and west of the Shantar Islands, including Shantar Bay (Tugur Bay), Mercury Bay (Ulban Bay), and Southwest Bay (Uda Gulf). On 28 July 1854, the New Bedford ship Isabella reported as many as 94 ships in sight from her deck in Shantar Bay alone. As the ice usually left the bays and gulfs in July or August, bowheads were left with nowhere to seek refuge, resulting in what has been called a "hunter's paradise". Whaling in these confined conditions and the sheer number of ships and boats cruising about also led to the recovery of numbers of "stinkers", dead whales that had been lost by other vessels; right whales, on the other hand, were caught in "open, often rough water", so when they sank they were lost in these deeper waters.
The ships would anchor in one of these bays and send out whaleboats to cruise for whales for days or even weeks. They searched for whales during the long daylight hours and camped on the beach at night. Once they found a whale, they typically sailed up to it, fastened to it with hand-held harpoons, and killed it either with hand-held lances or (beginning in the late 1850s) fired bomb lances into them from shoulder guns. Whales were usually towed to the ship, but distance and ice sometimes forced the men to tow whales ashore at high water, flense them at low water, and raft the blubber to the ship. Boat crews were often lost in the dense fogs prevalent in these waters. Fortunately, most were picked up by other vessels and safely returned to their ships. In September the fleet would rendezvous at the anchorage south of Feklistova, where they could obtain wood and water and repair any damage to their vessels. They usually left in October due to persistent stormy weather. Between 1851 and 1867, over twenty ships were lost in these storms, were run ashore and wrecked during a dense fog, or were stove by the ice and abandoned. Most of the crews were rescued by nearby vessels, but some perished, either drowning in their attempt to reach shore or dying of cold, hunger, or illness.
In late May 1865, the Confederate States Navy steamer Shenandoah sailed into the Sea of Okhotsk to hunt Union whaling ships. The ship spent more than three weeks there, but because of the dangerous ice, only destroyed one Union whaleship. It then moved on to the Bering Strait where it burned or bonded a number of the American whaleships, capturing 24 ships.
During the Cold War, the Sea of Okhotsk was the scene of several successful U.S. Navy operations (including Operation Ivy Bells) to tap Soviet Navy undersea communications cables. These operations were documented in the book Blind Man's Bluff: The Untold Story of American Submarine Espionage. The sea (and surrounding area) were also the scene of the Soviet PVO Strany attack on Korean Air Flight 007 in 1983. The Soviet Pacific Fleet used the Sea as a ballistic missile submarine bastion, a strategy that Russia continues.
In the Japanese language, the sea has no traditional Japanese name despite its close location to the Japanese territories and is called Ohōtsuku-kai (オホーツク海), which is a transcription of the Russian name. Additionally, Okhotsk Subprefecture, Hokkaidō which faces the sea, also known as Okhotsk region (オホーツク地方, Ohōtsuku-chihō), is named after the sea.
29 zones of possible oil and gas accumulation have been identified on the Sea of Okhotsk shelf, which runs along the coast. Total reserves are estimated at 3.5 billion tons of equivalent fuel, including 1.2 billion tons of oil and 1.5 billion cubic meters of gas.
On 18 December 2011 the Russian oil drilling rig Kolskaya capsized and sank in a storm in the Sea of Okhotsk, some 124 km from Sakhalin Island, where it was being towed from Kamchatka. Reportedly its pumps failed, causing it to take on water and sink. The platform carried 67 people, of which 14 were initially rescued by the icebreaker Magadan and the tugboat Natftogaz-55. The platform was subcontracted to a company working for the Russian energy giant Gazprom.