It is quickly becoming clear that offshore hydrocarbon development is costly, polluting and dangerous, even before considering an oil spill. No matter how you look at it, the impacts are far-reaching and long-lasting.
Since the Gulf of Saint-Lawrence is a small, semi-closed inland sea with complex sea currents (approximately 6.5 times smaller than the Gulf of Mexico), the impacts of an oil spill could have serious consequences. According to the first Strategic Environmental Assessment report (PDF) by the Quebec government, "it is generally accepted that oil spills can cause immediate and catastrophic damage to coastal communities, both in terms of losses in biomass and biodiversity, despite the resilience of several species [...]".
Five provinces border the Gulf of St. Lawrence, and communities rely on it for socio-economic activities. Overall, a spill in this area would have a catastrophic effect on the Magdalen Island population. In the Magdalen Islands alone (located near "Old Harry"), fishing activities directly and indirectly impact 75 per cent of the local population and generate annual revenues of nearly $78 million. The tourism industry that is essential to all maritime economies would also be greatly affected by an oil spill.
Beyond the socio-economic aspects, the Gulf of Saint-Lawrence is a unique and fragile ecosystem essential to the reproduction, growth and migration of hundreds of marine species. Several of these species are endangered, such as the codfish, the blue whale and the leatherback turtle. Considering that even under the best circumstances, only 15 per cent of oil spills can be cleaned, it's clear that the risks associated with oil development far outweigh the benefits. Even the smallest quantities of oil and sludge can harm marine life across an extensive area, and a shoreline can remain polluted for decades after a major oil spill (the effects of the Exxon Valdez spill from 20 years ago are still being felt today).
It is worth noting that risks associated with offshore incidents are consistently under-assessed by drilling companies, as demonstrated by the numerous incidents in various offshore drilling regions.