Observing the “ladder of migrations” to the deep sea

• Applicant: Dr. Jan Taucher
• Subject Area: Oceanography
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564897882

The deep ocean is the largest but least-understood habitat on Earth. As life at depth depends on primary production in the surface, pathways of “vertical connectivity” are critical in linking ecosystems across the water column. One of the most enigmatic phenomena is the so far virtually unexplored “ladder of vertical migrations”: this mechanism is hypothesized to link food-webs across several thousands of meters through synchronized and spatially overlapping vertical migrations of a multitude of species in increasingly deeper water layers. This cruise addresses this knowledge gap and will be an integral part of the ERC Consolidator project SEA-THROUGH. We will study the occurrence and functioning of the “ladder of migrations” in the subtropical and tropical North Atlantic by applying novel in situ imaging technologies, which provide unparalleled and highly detailed observations of deep-sea organisms. Supported by state-of-the-art methods (eDNA, acoustics, food-web tracers), this will allow us to resolve the ecological complexity, and spatial and temporal scales, to identify the “ladder of migrations”. Beyond this primary objective, the cruise will provide a holistic picture of biodiversity and food-web structure from the surface down to >5000m depth, thereby yielding new insights into the functioning of deep-sea ecosystems, their vertical connectivity, and differences between regions with contrasting productivity. To reach these objectives, we will assemble an international team of scientists combining expertise on in situ imaging technology and computer science, deep-sea ecology and taxonomy, as well as food-web studies.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 2520: Infrastructure area - Research Vessels
• International Connection: Spain
• Co-Investigator: Dr. Véronique Merten
• Cooperation Partner: Professor Dr. Santiago Hernández León