An integrated dataset of hydrological, meteorological, oceanographic and water-column biogeochemical observations in the Mar Menor coastal lagoon, southeastern Spain

The Mar Menor coastal lagoon (SE Spain) is a highly dynamic and vulnerable semi-enclosed system that has undergone severe environmental degradation in recent decades due to cumulative anthropogenic pressures. Here we present an integrated, harmonised dataset compiling hydrological, meteorological, oceanographic, and water-column biogeochemical observations collected across the lagoon and its watershed. The dataset spans from 1933 to early 2025, with most records covering the period since 1981, and combines data from in situ monitoring programmes, autonomous platforms, remote sensing products, and regional observational networks.

The data are organised into five thematic categories: hydrology, meteorology, oceanography, biogeochemistry, and particles and optics, providing a consistent framework to characterise environmental variability across the system. All datasets are distributed in NetCDF format following CF-1.8 conventions, ensuring interoperability and facilitating reuse. A harmonisation workflow was applied to standardise temporal and spatial references and metadata, while preserving original measurement units and quality control procedures.

This dataset provides a comprehensive, high-resolution observational basis for studying land–sea interactions, eutrophication processes, and ecosystem responses in coastal lagoons. It is intended to support environmental monitoring, model development, and evidence-based management of vulnerable coastal systems under increasing climatic and anthropogenic pressures.