Canada is once again debating a northern pipeline, a project that would move Alberta oil to the British Columbia coast and open up tanker traffic along some of the most fragile, remote, and culturally significant marine environments in the country. A new agreement between the federal government and Alberta has put the idea back on the table, but many are sounding alarms. Rick Steiner is a renowned marine conservationist who spent 30 years as a professor with the University of Alaska, working across the Arctic, Prince William Sound, and Anchorage. He spoke to Andrew Carter.