The Culturing Crisis: Why Aquatic Microbiology Needs More than Sequences

Abstract Microbial communities are essential components of aquatic ecosystems, yet a stark contrast persists between the vast diversity revealed by environmental sequencing and the limited taxa recoverable by culturing. This disparity has contributed to a shift toward sequencing due to its cost‐effectiveness and broad applicability to ecological questions. Despite this, culturing remains essential for understanding microbial physiology and function. Here, we compare published culturing efforts between freshwater and marine ecosystems, focusing on select phytoplankton representatives, and present a case study of a successful culture collection. We highlight the critical need to sequence the genome of isolates to build reference repositories for aquatic science. We conclude with a call to action for expanded, standardized culture collections that bridge the gap between sequencing discovery and functional understanding.