Subterreanean estuaries: A source or sink of contaminants of emerging concern to the coastal ocean?

Submarine groundwater discharge (SGD) is an understudied vector for pollution to the coastal ocean.

Earlier work demonstrated that SGD is a major source of nutrients, carbon, and metals to the ocean, but it remains unclear whether SGD is a source or sink of contaminants of emerging concern (CECs) to coastal waters. Many CECs can have negative ecological impacts even in trace quantities.

For instance, disruption to invertebrate reproductive health or promotion of antimicrobial resistance have been directly linked to CECs in numerous studies. Before reaching the ocean, SGD travels through the subterranean estuary, a natural biogeochemical hotspot.

I recently obtained initial evidence that SGD can release CEC compounds such as pharmaceuticals and industrial chemicals to the coastal ocean, but do not have insight into how microbial processes may alter CECs in subterranean estuaries.

I will study CEC behavior in the subterreanean estuary to resolve biogeochemical processing driving CEC release from contrasting coastal aquifer.

I will rely on an interdisciplinary combination of field, lab, and modeling experiments to establish the controlling factors governing CEC behavior within subterranean estuaries and their eventual release to the coastal ocean via SGD.

Field experiments will be conducted in contrasting silicate and carbonate systems to cover the wide range of conditions existing along the European coastline. Laboratory column experiments and groundwater modeling will provide conceptual insight into drivers of CEC in SGD.

I will be based at the University of Gothenburg (UGOT), Sweden with a secondment in Germany and close collaboration with researchers in Spain, France, and Poland. These results will inform future EU initiatives and provide key information for upcoming EU CEC watchlists.