In situ pore water sampling in deep intertidal flat sediments

Abstract

In this study, we present a multilevel in situ pore water sampler that allows pore water sampling down to 5 m sediment depth. The sampler forms a crucial tool to study biogeochemical processes on different time scales in advective pore water systems. After insertion into the sediment, the sampler stays on site, allowing repetitive sampling at identical locations and depth intervals. The sampler has been successfully tested for 1 year in sandy sediments in the backbarrier tidal flats of Spiekeroog Island at the German North Sea coast. Depth profiles of redox‐sensitive elements show a high depth resolution and are not affected by oxidation artifacts during extraction. Seasonal variations because of advection and changing microbial activity are apparent for some element species even at sediment depths of 5 m.