This dataset is a subset of "WFD Classification Status Cycle 2" and contains classification data for Winter Dissolved Inorganic Nitrogen (Winter DIN) in transitional and coastal water bodies. Physico-chemistry, in this case Winter DIN, is a supporting element that underpins the ecological status of a transitional or coastal water body. Data consisting of Winter DIN, salinity and Suspended Particulate Matter (SPM) records are run through the Winter DIN Water Framework Directive (WFD) classification tool. The actual (observed) values of Winter DIN are compared with a predicted value, using a different method for Clear water bodies and Not-Clear water bodies (these categories are based on average SPM). Clear waters are classified using the predicted relationship between average Winter DIN and average salinity in pristine waters; not-clear waters are classified using the predicted relationship between a 99%ile value of Winter DIN and average SPM in pristine waters. The comparison between the observed and expected values of Winter DIN is used to produce a Winter DIN classification (High, Good or Moderate only) of a transitional or coastal water body for WFD purposes. Attribution statement: © Environment Agency copyright and/or database right 2016. All rights reserved.