This is a collection of transcripts from interviews conducted by Gregor Halfmann as part of the ERC project "The Epistemology of Data-intensive Science". The interviews served as the empirical basis for Halfmann's PhD thesis "Seafarers, Silk, and Science: Oceanographic Data in the Making", submitted at the University of Exeter in July 2018. The interviews relate to the research practices, in particular the production and processing of research samples and scientific data, by marine ecologists and biological oceanographers working at the Marine Biological Association of the UK and for the Continuous Plankton Recorder Survey. Researchers have consented to have these transcripts made available as Open Data.