The introduction of a large infrastructure of marine energy technology along coastal environments raises some concern on how this will impact on the marine environment. While there are a number of potential environmental impacts of wave energy devices (eg, collision) the focus of this chapter is on the primary ecological processes that may be influenced by changes in the hydrodynamics as a direct result of the installation of wave energy converters (WECs). These processes include sediment transport, organism transport, pollution, and biogeochemical processes. While full-scale wave energy farms are still in the development phase, the most effective way to predict the environmental impacts of large infrastructure in the coastal marine environment is by coupling ecological with hydrodynamic modelling. This chapter therefore is designed to provide guidance on what factors should be considered when developing a coupled hydrodynamic-ecological model when modelling WEC arrays.