Nutrient data for autumn 2018 and spring 2019 in the Celtic Sea

Nutrient concentration data collected on the RV Cefas Endeavour as part of CEND17_18, CEND03_19 and CEND04_19, including concentrations of nitrite, nitrate, ammonia, phosphate and silicate. Samples were collected for use in eutrophication assessments and to test the Ferrybox water sampler. Samples were collected using three different methods: ( 1.)Manually from the continuous flow (CF) with mercuric chloride added. ( 2.)Manually from the continuous flow then frozen. ( 3.)Automatically with a water sampler attached to the Ferrybox with mercuric chloride added.