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Marine fish species that form spawning aggregations are often vulnerable to exploitation, such as the European bass (Dicentrarchus labrax). Information on bass spawning aggregations is not well resolved temporally and spatially. Otolith daily growth increment (DGI) counts were conducted on 0-group bass collected in July-August 2014 & 2019 from seven settlement estuaries in the Irish and Celtic seas, to estimate the timing of spawning. These timings parameterised three-dimensional hydrodynamic and Lagrangian particle tracking models, run in reverse, to identify probable spawning locations. Estimated spawning occurred between April-May (inshore and offshore) < 200 km from each settlement area. At least two broad spawning areas were predicted: the central Irish Sea that led to post-larval recruitment in north Wales and northwest England, and the southern Irish Sea/Celtic Sea that led to post-larval recruitment in south Wales. Results indicate the current seasonal closure for northern stock bass may not protect spawning events that drive recruitment into settlement sites in Wales and northwest England. Surface temperatures and wind- and tide-driven surface currents determined the connectivity between spawning and settlement sites. Atmospheric drivers are expected to change in the future and management needs to account for potential regional shifts in spawning times and locations.

Tidal energy has the opportunity to bring reliable electricity to remote regions in the world. A resource assessment, including the response of the tidal stream resource to fluctuations in the Indonesian Through Flow (ITF) is performed using the Regional Ocean Modelling System (ROMS) to simulate four different scenarios for flow through the Lombok Strait in Indonesia. Tidal currents simulated with a variable ITF are compared against a tide-only (TO) simulation to identify how the ITF spatially changes the resource across the Lombok Strait. We find that the uncertainty in the tidal currents from the TO simulation is 50% greater than the variable ITF simulation. To identify change to resource, surface velocities from Strong ITF and Weak ITF scenarios are considered. As a result of the fluctuations in the ITF, certain characteristics, such as the asymmetry and magnitude, of the tidal current vary greatly. However, the magnitude of change is variable, with regions to the west of the strait experiencing greater modulation than in the east, suggesting that resource uncertainty can be minimised with selective site positioning.

Tidal energy has the opportunity to bring reliable electricity to remote regions in the world. A resource assessment, including the response of the tidal stream resource to fluctuations in the Indonesian Through Flow (ITF) is performed using the Regional Ocean Modelling System (ROMS) to simulate four different scenarios for flow through the Lombok Strait in Indonesia. Tidal currents simulated with a variable ITF are compared against a tide-only (TO) simulation to identify how the ITF spatially changes the resource across the Lombok Strait. We find that the uncertainty in the tidal currents from the TO simulation is 50% greater than the variable ITF simulation. To identify change to resource, surface velocities from Strong ITF and Weak ITF scenarios are considered. As a result of the fluctuations in the ITF, certain characteristics, such as the asymmetry and magnitude, of the tidal current vary greatly. However, the magnitude of change is variable, with regions to the west of the strait experiencing greater modulation than in the east, suggesting that resource uncertainty can be minimised with selective site positioning.