A photo‐identification technique based on the unique detail of the head markings of individual fish was developed and utilised in a long‐term (>10 years) study at four discrete populations of the southern blue devil ( Paraplesiops meleagris ), a small demersal fish endemic to Australia's Great Southern Reef (GSR). The study revealed novel information on its life history and behaviour, including that population sizes were relat...

Marine fisheries in coastal ecosystems in many areas of the world have historically removed large‐bodied individuals, potentially impairing ecosystem functioning and the long‐term sustainability of fish populations. Reporting on size‐based indicators that link to food‐web structure can contribute to ecosystem‐based management, but the application of these indicators over large (cross‐ecosystem) geographical scales has been lim...