Using High Frequency In-Situ Monitoring to Gain New Insights into Irish Aquatic Systems

Until recent decades, most monitoring of surface waters relied exclusively on samples analysed in the laboratory for ecologically and management-relevant parameters. It is now possible, however, to automatically monitor many parameters using in-situ sensors and to provide remote web-based access to these data. Such data are typically provided at frequencies of minutes rather than at the weekly, fortnightly or monthly intervals typical of traditional monitoring and therefore capture both short-term change and, for inter-annual deployments, long-term trends. Here we give an overview of the use of high frequency monitoring (HFM) in Ireland and present case studies from a set of four sites, representative of the catchment-stream-lake-estuary continuum, to illustrate new insights that such deployments can provide. These include effects of cattle access on stream turbidity; biogeochemical processing in agricultural streams; effects of summer storms on dissolved organic matter in a catchment and lake; and changes in a trophic index in an estuarine setting. We discuss the additional information provided by such systems when compared to traditional monitoring, some of the challenges related to their use, and assess the future use of HFM to inform management of and policy for aquatic systems on the island of Ireland.