Continuously monitored water quality parameters from three open-water sites in a tidal salt marsh channel in New Jersey, USA from June 2021 to June 2024

This dataset includes high-frequency measurements of key physical and biogeochemical parameters (depth, salinity, temperature, dissolved oxygen concentration and % saturation, pH, turbidity, chlorophyll a) collected at 10-minute intervals from three open-water platforms in a salt marsh tidal channel. The marsh is located landward of Seven Mile Island, a populated barrier island in Cape May County, New Jersey, and is a part of the Seven Mile Island Innovation Laboratory (SMIIL), a research initiative focused on advancing dredging and marsh restoration practices. Data were collected using In-Situ Aqua TROLL 600 multiparameter sondes, which were cleaned, recalibrated, and swapped every 4–12 weeks to enable continuous monitoring. Turbidity and chlorophyll a data are included but have highly variable coverage. The dataset comprises 18 deployments, which have been appended and quality controlled. Meteorological data (air temperature, relative humidity, atmospheric pressure) from a centrally located Young ResponseONE Weather Transmitter and Onset HOBO water level logger, along with ERA5 wind speed data, are provided for the same time period. This high-resolution, multi-year dataset supports the analysis of aquatic ecosystem metabolism and environmental variability in a marsh-dominated estuary, a system type that remains underrepresented in long-term, high-frequency monitoring efforts.