Water column sonar data collected by echosounders are essential for marine ecosystem research, allowing the detection, classifi cation, and quantification of fish and zooplankton from many different ocean observing platforms. However, broad usage of these data has been hindered by the lack of software tools that allow intuitive and transparent data access, processing, and interpretation. We address this gap by developing Echostack, a toolbox of open-source packages leveraging distributed computing and cloud-interfacing libraries in the scientific Python ecosystem. These tools can be used individually or orchestrated together, which we will demonstrate in an end-to-end workflow.