Dataset contains hydrochemistry data from the Romanian inner shelf waters (bottom depths between 15 and 67 m), in July 2022. Data were collected on board R/V Mare Nigrum, during a cruise conducted within the national project "Multidisciplinary research to improve knowledge of the climate change and human pressure interaction and its effects on the Black Sea ecosystem" – PN 19 20 01 02. Twenty-one stations distributed along 4 main transects (Sf. Gheorghe-SE, Portita-SE, Constanta-SE, and Mangalia-E) were performed for water column investigations by the GeoEcoMar team. In situ measurements of physical-chemical seawater parameters were done at each sampling station using a YSI EXO2 multiparameter sonde. Seawater samples were collected with 5L Niskin bottles from different depths and further analyzed in the GeoEcoMar lab for nutrients and chlorophylls (both by spectrometry).