Mercury, DOC and hydrology data of James Bay rivers from summer 2018 to summer 2019

This dataset includes chemical and physical data measured in situ in surface water of natural and dammed rivers of Eastern James Bay, in Northern Quebec, Canada. Samples were collected by boat or helicopter, mostly hovering but sometimes landing on the water or on the shore, during sampling campaign of summer 2018, fall 2018, winter 2019, spring 2019 and summer 2019 (see data set for precise dates). Mercury samples were collected using a peristaltic pump, and an in-line Whatman 0.45 µm filtration capsule attached to the tubing in case of filtered samples, with a clean sampling protocol to avoid any contamination by trace metals. Dissolved organic carbon, colored dissolved organic carbon and water isotopes (deuterium excess) data are also included in this dataset. Land cover data was derived from Land use 2010 dataset (Agriculture and Agri-Foods Canada, 2015). Hydrological data used to calculate annual and seasonal discharges were obtained through Hydro Quebec from historical hydrometric stations of and from new hydrometric stations deployed in 2018 and 2019 for this project. The purpose of the data was to explore the biogeochemical drivers of mercury concentrations, exports and yields in large northern rivers of Eastern James Bay.