Tides and Transport: Application to Lofoten and Vester°alen, Northern Norway

Abstract

Tides are important drivers for the motion in many coastal seas. While tides mainly move water back and forth, the interaction between tidal currents and topography might induce residual currents and fluxes, providing an important transport component. The coastal sea around Lofoten and Vesterålen is an area where strong tidal currents interact with complex coastlines and topography. However, the tidally-induced transport has gained little attention. The coastal sea around Lofoten and Vesterålen is the main spawning ground for the Northeast Arctic cod, the most important species in Norwegian fisheries. The recruitment of this fish stock depends on ocean currents transporting eggs and larvae to its nursing ground in the Barents Sea. Thus, to identify vulnerable areas and predict fish recruitment for sustainable fisheries management, understanding the processes determining transport pathways is vital. This thesis shows the importance of tidally-induced transport in Lofoten and Vesterålen. The thesis comprises theoretical and model studies investigating different transport processes and a comparison study on particle transport with and without tides. The results show that tides largely impact the particle transport in the region, both by increasing the transport from a spawning-ground in Vestfjorden to the shelf and by influencing which routes the particles take.