Confusion reigns? A review of marine megafauna interactions with tidal-stream environments

Energetic tidal-stream environments are characterized by frequent, variable, yet broadly predictable currents containing ephemeral flow structures that change across multiple spatio-temporal scales. Marine mammals and seabirds (marine megafauna) often frequent such sites, but increasingly these locations are targeted for renewable energy extraction; little is known, however, about how marine megafauna use these habitats and any potential impacts. This review aims to summarize existing knowledge concerning usage by marine megafauna and considers their wider ecological significance. The review describes the physical processes occurring within tidal-stream environments that generate the oceanographic structures of potential ecological relevance, such as jets, boils, eddies, and fronts. Important physical features of these environments include lateral transport, turbulence-driven