Urban shading and artificial light at night alter natural light regimes and affect marine intertidal assemblages.

Urban development in many coastal cities has resulted in altered natural light regimes, with many coastal habitats being artificially shaded during the daytime by built structures such as seawalls and piers, while artificial light emitted from buildings and associated infrastructure creates pollution at night. As a result, these habitats may experience changes to community structure and impacts on key ecological processes such as grazing. This study investigated how changes to light regimes affect the abundance of grazers on natural and artificial intertidal habitats in Sydney Harbour, Australia.