evidence: Bolshoi Ussuriysky Island (Russian: Большо́й Уссури́йский о́стров, romanized: Bol'shoy Ussuriyskiy Ostrov), or Heixiazi Island (simplified Chinese: 黑瞎子岛; traditional Chinese: 黑瞎子島; pinyin: Hēixiāzi Dǎo; lit. 'black bear island'[a]), is a sedimentary island at the confluence of the Ussuri and Amur rivers. Since the Sino-Russian Border Agreement that was fully implemented in 2008, Bolshoy Ussuriysky Island was divided between China and Russia. China was given control over part of the island, and Russia retained the rest. Since then, the issue has been peacefully settled, and China no longer claims the entire island. It has an area of about 327 to 350 km2 and is bounded closely by Yinlong/Tarabarov Island, and over 90 islets.[b] Its position at the confluence of the Amur and the Ussuri, and right next to the major Russian city of Khabarovsk, has given it great strategic importance. [...] On October 14, 2004, the Complementary Agreement between the People's Republic of China and the Russian Federation on the Eastern Section of the China-Russia Boundary was signed, in which Russia agreed to relinquish control over Yinlong Island and around half of Bolshoy Ussuriysky. About 170 square kilometres of Bolshoy Ussuriysky was transferred to mainland China, while the rest remained under Russia's jurisdiction.[citation needed] In return, mainland China agreed to drop all territorial claims to the remainder of Bolshoy Ussuriysky kept by Russia and received the right to navigate ships along the main channel of the Amur.[citation needed]