Coastlines are dynamic features, reshaped by tides, storms and longer‑term processes such as erosion and sea‑level rise. Monitoring those changes accurately over years requires repeated measurements from fixed locations — a labour‑intensive task for professional teams.
To broaden the scope of observation, the CoastSnap citizen‑science initiative enlists beachgoers to take standardised photographs from dedicated vantage points. The project began in Australia in 2017 and has since expanded to more than 200 sites around the world. Participants typically rest their phones on a small cradle and follow instructions on a nearby sign to capture and submit images via an app.
The standardised images form time series that researchers can use to track shoreline position and how it evolves after particular weather events or across seasons. Because the photos are taken from the same marked viewpoints, they provide consistent visual records that complement other monitoring methods and widen spatial and temporal coverage without requiring continuous field teams.
Organisers say the simplicity of the setup — a camera phone, a cradle and a sign pointing users to the app — has helped the scheme spread to beaches worldwide. For scientists, the resulting archive of photographs is a valuable resource for studying coastal change, informing local management and improving understanding of how beaches respond to natural variability and human pressures.
While CoastSnap relies on volunteer contributions, it demonstrates how distributed public participation can produce robust datasets at scales that would be difficult and costly for researchers alone. The approach illustrates a growing trend in environmental science: blending low‑cost technology with community engagement to monitor changing landscapes over time.