These data addressed the COMPASS programme objective of developing cross-border capacity by drawing together two currently unrelated national hydrodynamic models, the Irish Northeast Atlantic Model and the Scottish Shelf Model (SSM), or an alternative west coast domain, into an integrated model system for the target region.

This interfaced hydrodynamic model itself addressed one of the programme’s required model outputs, providing simulations of the evolving marine environment, but it also provided the underpinning for two further models. These considered biological connectivity between sites across the region and hydrodynamic habitat type, both of key importance in understanding, developing and managing Marine Protected Area (MPA) networks.

Initial development of the connectivity model followed the release of the 2016 hydrodynamic hindcast, with results updated and released when the second year of hindcast was available. Source locations/habitats, dispersal date/duration and behaviour of specific organisms were chosen based on the best available information to represent existing or potential MPA sites and priority species. Prior feedback on these aspects was sought from organisations involved in the design and/or management of the MPA network, including NWPS (Ireland), DOENI and CNCC (Northern Ireland), Marine Scotland and SNH (Scotland) and JNCC.

Development of the hydrodynamic habitat model proceeded in parallel with the connectivity model, similarly using the initial hydrodynamic model hindcasts. A series of data levels were constructed of ecologically relevant physical parameters (including tidal current speed, residual current speed, turbulent intensity, level of summer stratification, level of winter stratification, etc.).

The habitat model defined habitat types within this parameter space, leading to the production of hydrodynamic habitat maps. While hydrodynamic factors are key determinants of marine habitat a full habitat description also requires information on seafloor topography, substrate type, etc.