The 2016 survey continues the Marine Institute’s Winter Nutrients monitoring that commenced in 1990/91. In 2011 this survey was reestablished as a winter environmental survey with a broader remit to provide supporting information for OSPAR and Water Framework Directive (WFD- Directive 2000/60/EC) assessments and also to maintain the winter time series on key biogeochemical parameters in Irish waters in response to pressures such as land based inputs of nutrients and climate change. Since 2011 the survey circumnavigates the Island of Ireland every two years. This 13 day survey took place in February 2016 on board the R.V. Celtic Voyager. The survey was designed to collect multidisciplinary information on physical conditions, water chemistry (dissolved nutrients, dissolved oxygen, total alkalinity (TA), dissolved organic carbon (DOC), dissolved trace metals, and total organic carbon, salinity), sediment chemistry (persistent organic pollutants POPs and trace metals), sediment particle size distribution and benthic macroinvertebrates. In total 203 underway stations were sampled for surface water chemistry via the onboard non-toxic system; 96 CTD deployments were undertaken, typically at surface and bottom but occasionally at mid-depths where some stratification was seen in the water column, resulting in 197 CTD sampling events. The survey aims to fulfil Ireland's requirements under the Coordinated Environmental Monitoring Programme (CEMP) of the 1992 'Oslo Paris Convention for the Protection of the North East Atlantic' (OSPAR) and to contribute to assessments under the Common Procedure for the Identification of the Eutrophication Status of the OSPAR maritime area.