A pilot Coastal Observatory has been established in Liverpool Bay (Eastern Irish Sea, UK) that integrates (near) real-time measurements with coupled models in a pre-operational coastal prediction system and displays all measurements and model outputs on the Coastal Observatory web-site (http://coastobs.pol.ac.uk). The system began in 2002 and will run beyond 2006. The aim is to understand a coastal sea’s response to natural forcing and the consequences of human activity. The foci are the impacts of storms, seasonality, and variations in river discharge (freshwater and nutrients) on the functioning of Liverpool Bay. One aim is to integrate a variety of measurement sampling strategies – timeseries, monthly spatial surveys, daily instrumented ferries, HF radar – both as an integrated measurement array and with 3-D hydrodynamic and ecosystem models. The first 2 years of operation will be reviewed and the relevance of this approach as a scientific underpinning for the ecosystem based approach to marine management is considered.