Oceans play a huge role in defining Canada. With over 243,000 km along the Atlantic, Arctic and Pacific oceans, Canada has the longest coastline in the world. But the oceans are in peril...CO2, pollution, climate change and overfishing, are all contributing to major changes in the oceans' ability to sustain themselves A substantial part of Canada's economy is linked to the oceans. Between fisheries, navigation, international trade, offshore oil and gas, tourism and recreation, the ocean is an essential part of this country.