Reflecting on an anniversary. The 1970 SS Arrow oil spill in Chedabucto Bay, Nova Scotia, Canada.

Fifty years ago, the tanker SS Arrow ran aground in Chedabucto Bay on the east coast of Canada, causing a massive spill of Bunker C oil in winter conditions. This article reflects on this anniversary, briefly describing the spill response and the considerable follow-up research over five decades on the fate and effects of oils spilled in northern cold marine waters. Importantly, the spill led to considerable work in Canada on spill control and bioremediation measures, and advice about oil spills as a marine pollutant of global importance.