The seafloor is the final resting place for much of the materials washed into the ocean from land, for minerals forming in the ocean, and for detritus from organism that once populated the sunlit surface ocean. But the exchange between the seafloor and the overlying water column is not a one-way process. Once the material settles on the seafloor it is often subjected to intense biological reworking and recycling. Some of this recycled substrate makes it back into the water column, and if it is picked up by upwelling currents it might even be returned to the sunlight surface to once again supply nutrients to the biota, completing the cycle. The exchange the between the water column and the seafloor is especially important in the shallow waters of the highly productive coastal oceans. In our department we study the environmental controls of this bi-directional exchange process and linkages between biology and chemistry.