Arctic Ocean relate to the radioactive contamination of the Arctic Ocean from, for example, Russian radioactive waste dump sites in the Kara Sea and Cold War nuclear test sites such as Novaya Zemlya. In addition, Shell planned to drill exploratory wells in the Chukchi and Beaufort seas during the summer of 2012, which environmental groups filed a lawsuit about in an attempt to protect native communities, endangered wildlife, and the Arctic Ocean in the event of a major oil spill. On 16 July 2015, five nations (United States of America, Russia, Canada, Norway, Denmark/Greenland) signed a declaration committing to keep their fishing
Severnaya Zemlya as Arctic lemming, which is present on all of the large islands and, in some places has been recorded to reach a density of 500 per km (1,300 per sq mi). The Arctic fox ("Alopex lagopus") has been known to den on the islands, with several hundred observed in the 1980s. Other mammals occasionally observed include the wolf ("Canis lupus"), the polar bear ("Ursus maritimus"), ermine ("Mustela erminea"), Arctic hare ("Lepus timidus"), and reindeer ("Rangifer tarandus"). The discovery of Severnaya Zemlya is the subject of Veniamin Kaverin's novel "The Two Captains" as well as its stage adaptation, "Nord-Ost". Severnaya Zemlya