Many marine plants and animals use carbonate minerals to build their shells and skeletons. The most well-known examples include coral and shellfish, but several important groups of plankton (organisms that spend their lives afloat in the ocean) do the same. The BEYΩND project aims to better understand what drives these minerals to dissolve in the ocean, which is a key part of the global carbon cycle that has an important influence on Earth’s climate. BEYΩND includes a research expedition to investigate dissolution in situ in the ocean, which has now underway. Together with collaborators from several Dutch (NIOZ, UU, Naturalis, UvA, RUG) and Belgian (VLIZ) institutes, we are conducting a wide range of observations and experiments including measuring seawater chemistry, catching plankton and other particles with various nets and sediment traps, collecting seafloor sediment, and deploying a mooring carrying different types of carbonate minerals across a wide range of depths.