Research project Hadal trenches as global sink for hazardous pollutants (HADAL-POP)

Sediment burial is a major removal pathway for persistent organic pollutants (POPs). Hadal trenches represent the deepest part of the ocean; they are hotspots for organic carbon burial as well as decomposition of organic matter, therefore likely hotspots also for POP burial, as transport of organic matter and POPs goes hand in hand and organic matter degradation increases its capacity to store POPs. In HADAL-POP we will perform a cruise to the Japan Trench to test hypotheses on how biogeochemistry governs the sediment capacity to accumulate pollutants. Access to samples from five hadal trenches will allow us to apply our findings from the Japan Trench on other regimes, and thereby investigate principles that govern pollutant burial also in more polluted systems. Occurrence of currently used chemicals on the remote hadal seafloor is a call to decision makers for improving current chemicals management.