The North Sea is a partially enclosed body of the Atlantic Ocean located at the edge of northwestern Europe. It is bordered by the United Kingdom on the west, Norway and Denmark on the east, and The Netherlands and Germany on the south. The North Sea possesses the world's busiest shipping port, Rotterdam, The Netherlands, which processes 250 million tons of cargo per year. Coastal industries, including fishing, oil and gas extraction, and sand-gravel mining, are cornerstones of the regional economy and culture. The region's fishing, oil drilling, and mining industries have had major impacts on the North Sea. Overfishing, in particular, has impacted the ecological balance of this ocean environment Overall, it is estimated that more than 50 percent of the total reserves of North Sea oil had been removed from the undersea terrain as of 2008. The cold North Sea currents are plentiful in nutrients that support a diversity of marine species.