SEEP ecology – a multiproxy approach to establish a seabed ecological baseline in the North Sea prior to human activities in the subsurface

The SEEP and SEEP ecology projects were established to generate a preproduction and syn-production baseline which can distinguish between absence of hydrocarbons (HC), natural seepage, and environmental impacts related to HC exploration and production by a multiproxy approach. The results can also be used to establish a seabed ecological baseline in the North Sea prior to human activities in the subsurface and relevant for discussing the impact of offshore wind and marine infrastructure to determine the environmental health of the seabed pre/post human activities.
To develop a methodology for an ecological baseline we use three key communities that have widely differing roles in the marine ecosystem: microbes, benthic foraminifera, and bivalves. The microbial community reveal the presence of HC degrading microbes. The different benthic foraminiferal species have adapted to distinct environments with changing oxygen and food conditions and are therefore excellent candidates for the study of both past and recent ecological conditions. The bivalves are long lived filter feeders that deposit pollutants from the benthic and planktonic environment in their shells. ´They are present in the oldest parts of the marine sediment cores dating back at least 8000 years.