First assessment of anthropogenic impacts in submarine canyon systems off southwestern Australia.

We assessed the anthropogenic impacts on southwestern Australian submarine canyons by quantifying macro-litter discovered during Remotely Operated Vehicle surveys. The study area encompasses the Bremer canyon systems and Perth Canyon. The categories of macro-litter identified by our study are plastic, metal, aluminium, glass, fabric, mixed, derelict fishing gear, and unclassified. The anthropogenic impacts in the canyons explored is minimal, especially in the Bremer canyon systems, whereas Perth Canyon has comparatively more macro-litter, presumably due to intense maritime traffic and nearby urban development. On a global scale, however, the environmental status of southwestern Australian canyons is relatively pristine. This analysis provides a baseline for the monitoring and enduring stewardship of these habitats where lush and diverse biota, including deep-sea corals, thrive.