It remains unknown how tidal stream turbines could impact deep diving seabird populations such as auks Alcidae sp and cormorants Phalacrocorax sp. Predicting whether and how devices could affect populations is hampered by poor knowledge of what influences seabird foraging distributions in the tidal pass habitats favoured for installations. Here distributions of foraging seabirds are compared with a suite of concurrent environmental variables within the Fall of Warness, Orkney, UK to investigate associations between auks, cormorants and oceanographical processes. Results are presented for Atlantic puffins Fratercula arctica, black guillemots Cepphus grylle, common guillemots Uria algaa and European shags Phalacrocorax aristotelis. These studies provide the information that is needed to predict auk and cormorant distributions within tidal pass over different scenarios, revealing which and when species may interact with devices within these habitats.