The effects of experimental spills of natural gas condensate on three plant communities on Sable Island, Nova Scotia, Canada

We examined the effects of an experimental oiling with natural gas condensate on three plant communities on Sable Island, a sandy, temperate island located 160 km east of Nova Scotia in the Atlantic Ocean. The plant communities were: (i) a dune grassland dominated by Ammophila breviligulata; (ii) a herbaceous beach community dominated by Honckenya peploides; and (iii) a heath dominated by Empetrum nigrum, Myrica pensylvanica, Rosa virginiana, and Vaccinium angustifolium. The experimental treatments were: (i) control; (ii) sprayed with 6·3 litres of condensate/25 m² and (iii) sprayed with 12·5 litres/25 m². Initially, in all three communities there was a severe herbicidal effect on most above-ground plant tissues that were directly impacted by the condensate. However, below-ground perennating tissues were little affected by the hydrocarbon treatment, and the vigorous regeneration that issued from these tissues allowed an essentially complete recovery of most species after one or two post-spill growing seasons.